Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * clauses.c
4 : * routines to manipulate qualification clauses
5 : *
6 : * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
7 : * Portions Copyright (c) 1994, Regents of the University of California
8 : *
9 : *
10 : * IDENTIFICATION
11 : * src/backend/optimizer/util/clauses.c
12 : *
13 : * HISTORY
14 : * AUTHOR DATE MAJOR EVENT
15 : * Andrew Yu Nov 3, 1994 clause.c and clauses.c combined
16 : *
17 : *-------------------------------------------------------------------------
18 : */
19 :
20 : #include "postgres.h"
21 :
22 : #include "access/htup_details.h"
23 : #include "catalog/pg_language.h"
24 : #include "catalog/pg_operator.h"
25 : #include "catalog/pg_proc.h"
26 : #include "catalog/pg_type.h"
27 : #include "executor/executor.h"
28 : #include "executor/functions.h"
29 : #include "funcapi.h"
30 : #include "miscadmin.h"
31 : #include "nodes/makefuncs.h"
32 : #include "nodes/multibitmapset.h"
33 : #include "nodes/nodeFuncs.h"
34 : #include "nodes/subscripting.h"
35 : #include "nodes/supportnodes.h"
36 : #include "optimizer/clauses.h"
37 : #include "optimizer/cost.h"
38 : #include "optimizer/optimizer.h"
39 : #include "optimizer/plancat.h"
40 : #include "optimizer/planmain.h"
41 : #include "parser/analyze.h"
42 : #include "parser/parse_coerce.h"
43 : #include "parser/parse_func.h"
44 : #include "rewrite/rewriteHandler.h"
45 : #include "rewrite/rewriteManip.h"
46 : #include "tcop/tcopprot.h"
47 : #include "utils/acl.h"
48 : #include "utils/builtins.h"
49 : #include "utils/datum.h"
50 : #include "utils/fmgroids.h"
51 : #include "utils/json.h"
52 : #include "utils/jsonb.h"
53 : #include "utils/jsonpath.h"
54 : #include "utils/lsyscache.h"
55 : #include "utils/memutils.h"
56 : #include "utils/syscache.h"
57 : #include "utils/typcache.h"
58 :
59 : typedef struct
60 : {
61 : ParamListInfo boundParams;
62 : PlannerInfo *root;
63 : List *active_fns;
64 : Node *case_val;
65 : bool estimate;
66 : } eval_const_expressions_context;
67 :
68 : typedef struct
69 : {
70 : int nargs;
71 : List *args;
72 : int *usecounts;
73 : } substitute_actual_parameters_context;
74 :
75 : typedef struct
76 : {
77 : int nargs;
78 : List *args;
79 : int sublevels_up;
80 : } substitute_actual_srf_parameters_context;
81 :
82 : typedef struct
83 : {
84 : char *proname;
85 : char *prosrc;
86 : } inline_error_callback_arg;
87 :
88 : typedef struct
89 : {
90 : char max_hazard; /* worst proparallel hazard found so far */
91 : char max_interesting; /* worst proparallel hazard of interest */
92 : List *safe_param_ids; /* PARAM_EXEC Param IDs to treat as safe */
93 : } max_parallel_hazard_context;
94 :
95 : static bool contain_agg_clause_walker(Node *node, void *context);
96 : static bool find_window_functions_walker(Node *node, WindowFuncLists *lists);
97 : static bool contain_subplans_walker(Node *node, void *context);
98 : static bool contain_mutable_functions_walker(Node *node, void *context);
99 : static bool contain_volatile_functions_walker(Node *node, void *context);
100 : static bool contain_volatile_functions_not_nextval_walker(Node *node, void *context);
101 : static bool max_parallel_hazard_walker(Node *node,
102 : max_parallel_hazard_context *context);
103 : static bool contain_nonstrict_functions_walker(Node *node, void *context);
104 : static bool contain_exec_param_walker(Node *node, List *param_ids);
105 : static bool contain_context_dependent_node(Node *clause);
106 : static bool contain_context_dependent_node_walker(Node *node, int *flags);
107 : static bool contain_leaked_vars_walker(Node *node, void *context);
108 : static Relids find_nonnullable_rels_walker(Node *node, bool top_level);
109 : static List *find_nonnullable_vars_walker(Node *node, bool top_level);
110 : static bool is_strict_saop(ScalarArrayOpExpr *expr, bool falseOK);
111 : static bool convert_saop_to_hashed_saop_walker(Node *node, void *context);
112 : static Node *eval_const_expressions_mutator(Node *node,
113 : eval_const_expressions_context *context);
114 : static bool contain_non_const_walker(Node *node, void *context);
115 : static bool ece_function_is_safe(Oid funcid,
116 : eval_const_expressions_context *context);
117 : static List *simplify_or_arguments(List *args,
118 : eval_const_expressions_context *context,
119 : bool *haveNull, bool *forceTrue);
120 : static List *simplify_and_arguments(List *args,
121 : eval_const_expressions_context *context,
122 : bool *haveNull, bool *forceFalse);
123 : static Node *simplify_boolean_equality(Oid opno, List *args);
124 : static Expr *simplify_function(Oid funcid,
125 : Oid result_type, int32 result_typmod,
126 : Oid result_collid, Oid input_collid, List **args_p,
127 : bool funcvariadic, bool process_args, bool allow_non_const,
128 : eval_const_expressions_context *context);
129 : static List *reorder_function_arguments(List *args, int pronargs,
130 : HeapTuple func_tuple);
131 : static List *add_function_defaults(List *args, int pronargs,
132 : HeapTuple func_tuple);
133 : static List *fetch_function_defaults(HeapTuple func_tuple);
134 : static void recheck_cast_function_args(List *args, Oid result_type,
135 : Oid *proargtypes, int pronargs,
136 : HeapTuple func_tuple);
137 : static Expr *evaluate_function(Oid funcid, Oid result_type, int32 result_typmod,
138 : Oid result_collid, Oid input_collid, List *args,
139 : bool funcvariadic,
140 : HeapTuple func_tuple,
141 : eval_const_expressions_context *context);
142 : static Expr *inline_function(Oid funcid, Oid result_type, Oid result_collid,
143 : Oid input_collid, List *args,
144 : bool funcvariadic,
145 : HeapTuple func_tuple,
146 : eval_const_expressions_context *context);
147 : static Node *substitute_actual_parameters(Node *expr, int nargs, List *args,
148 : int *usecounts);
149 : static Node *substitute_actual_parameters_mutator(Node *node,
150 : substitute_actual_parameters_context *context);
151 : static void sql_inline_error_callback(void *arg);
152 : static Query *substitute_actual_srf_parameters(Query *expr,
153 : int nargs, List *args);
154 : static Node *substitute_actual_srf_parameters_mutator(Node *node,
155 : substitute_actual_srf_parameters_context *context);
156 : static bool pull_paramids_walker(Node *node, Bitmapset **context);
157 :
158 :
159 : /*****************************************************************************
160 : * Aggregate-function clause manipulation
161 : *****************************************************************************/
162 :
163 : /*
164 : * contain_agg_clause
165 : * Recursively search for Aggref/GroupingFunc nodes within a clause.
166 : *
167 : * Returns true if any aggregate found.
168 : *
169 : * This does not descend into subqueries, and so should be used only after
170 : * reduction of sublinks to subplans, or in contexts where it's known there
171 : * are no subqueries. There mustn't be outer-aggregate references either.
172 : *
173 : * (If you want something like this but able to deal with subqueries,
174 : * see rewriteManip.c's contain_aggs_of_level().)
175 : */
176 : bool
177 10326 : contain_agg_clause(Node *clause)
178 : {
179 10326 : return contain_agg_clause_walker(clause, NULL);
180 : }
181 :
182 : static bool
183 12848 : contain_agg_clause_walker(Node *node, void *context)
184 : {
185 12848 : if (node == NULL)
186 30 : return false;
187 12818 : if (IsA(node, Aggref))
188 : {
189 : Assert(((Aggref *) node)->agglevelsup == 0);
190 1276 : return true; /* abort the tree traversal and return true */
191 : }
192 11542 : if (IsA(node, GroupingFunc))
193 : {
194 : Assert(((GroupingFunc *) node)->agglevelsup == 0);
195 30 : return true; /* abort the tree traversal and return true */
196 : }
197 : Assert(!IsA(node, SubLink));
198 11512 : return expression_tree_walker(node, contain_agg_clause_walker, context);
199 : }
200 :
201 : /*****************************************************************************
202 : * Window-function clause manipulation
203 : *****************************************************************************/
204 :
205 : /*
206 : * contain_window_function
207 : * Recursively search for WindowFunc nodes within a clause.
208 : *
209 : * Since window functions don't have level fields, but are hard-wired to
210 : * be associated with the current query level, this is just the same as
211 : * rewriteManip.c's function.
212 : */
213 : bool
214 8704 : contain_window_function(Node *clause)
215 : {
216 8704 : return contain_windowfuncs(clause);
217 : }
218 :
219 : /*
220 : * find_window_functions
221 : * Locate all the WindowFunc nodes in an expression tree, and organize
222 : * them by winref ID number.
223 : *
224 : * Caller must provide an upper bound on the winref IDs expected in the tree.
225 : */
226 : WindowFuncLists *
227 2336 : find_window_functions(Node *clause, Index maxWinRef)
228 : {
229 2336 : WindowFuncLists *lists = palloc(sizeof(WindowFuncLists));
230 :
231 2336 : lists->numWindowFuncs = 0;
232 2336 : lists->maxWinRef = maxWinRef;
233 2336 : lists->windowFuncs = (List **) palloc0((maxWinRef + 1) * sizeof(List *));
234 2336 : (void) find_window_functions_walker(clause, lists);
235 2336 : return lists;
236 : }
237 :
238 : static bool
239 20694 : find_window_functions_walker(Node *node, WindowFuncLists *lists)
240 : {
241 20694 : if (node == NULL)
242 226 : return false;
243 20468 : if (IsA(node, WindowFunc))
244 : {
245 3158 : WindowFunc *wfunc = (WindowFunc *) node;
246 :
247 : /* winref is unsigned, so one-sided test is OK */
248 3158 : if (wfunc->winref > lists->maxWinRef)
249 0 : elog(ERROR, "WindowFunc contains out-of-range winref %u",
250 : wfunc->winref);
251 : /* eliminate duplicates, so that we avoid repeated computation */
252 3158 : if (!list_member(lists->windowFuncs[wfunc->winref], wfunc))
253 : {
254 6292 : lists->windowFuncs[wfunc->winref] =
255 3146 : lappend(lists->windowFuncs[wfunc->winref], wfunc);
256 3146 : lists->numWindowFuncs++;
257 : }
258 :
259 : /*
260 : * We assume that the parser checked that there are no window
261 : * functions in the arguments or filter clause. Hence, we need not
262 : * recurse into them. (If either the parser or the planner screws up
263 : * on this point, the executor will still catch it; see ExecInitExpr.)
264 : */
265 3158 : return false;
266 : }
267 : Assert(!IsA(node, SubLink));
268 17310 : return expression_tree_walker(node, find_window_functions_walker,
269 : (void *) lists);
270 : }
271 :
272 :
273 : /*****************************************************************************
274 : * Support for expressions returning sets
275 : *****************************************************************************/
276 :
277 : /*
278 : * expression_returns_set_rows
279 : * Estimate the number of rows returned by a set-returning expression.
280 : * The result is 1 if it's not a set-returning expression.
281 : *
282 : * We should only examine the top-level function or operator; it used to be
283 : * appropriate to recurse, but not anymore. (Even if there are more SRFs in
284 : * the function's inputs, their multipliers are accounted for separately.)
285 : *
286 : * Note: keep this in sync with expression_returns_set() in nodes/nodeFuncs.c.
287 : */
288 : double
289 348744 : expression_returns_set_rows(PlannerInfo *root, Node *clause)
290 : {
291 348744 : if (clause == NULL)
292 0 : return 1.0;
293 348744 : if (IsA(clause, FuncExpr))
294 : {
295 53966 : FuncExpr *expr = (FuncExpr *) clause;
296 :
297 53966 : if (expr->funcretset)
298 48558 : return clamp_row_est(get_function_rows(root, expr->funcid, clause));
299 : }
300 300186 : if (IsA(clause, OpExpr))
301 : {
302 3216 : OpExpr *expr = (OpExpr *) clause;
303 :
304 3216 : if (expr->opretset)
305 : {
306 6 : set_opfuncid(expr);
307 6 : return clamp_row_est(get_function_rows(root, expr->opfuncid, clause));
308 : }
309 : }
310 300180 : return 1.0;
311 : }
312 :
313 :
314 : /*****************************************************************************
315 : * Subplan clause manipulation
316 : *****************************************************************************/
317 :
318 : /*
319 : * contain_subplans
320 : * Recursively search for subplan nodes within a clause.
321 : *
322 : * If we see a SubLink node, we will return true. This is only possible if
323 : * the expression tree hasn't yet been transformed by subselect.c. We do not
324 : * know whether the node will produce a true subplan or just an initplan,
325 : * but we make the conservative assumption that it will be a subplan.
326 : *
327 : * Returns true if any subplan found.
328 : */
329 : bool
330 60636 : contain_subplans(Node *clause)
331 : {
332 60636 : return contain_subplans_walker(clause, NULL);
333 : }
334 :
335 : static bool
336 191778 : contain_subplans_walker(Node *node, void *context)
337 : {
338 191778 : if (node == NULL)
339 6462 : return false;
340 185316 : if (IsA(node, SubPlan) ||
341 185232 : IsA(node, AlternativeSubPlan) ||
342 185232 : IsA(node, SubLink))
343 328 : return true; /* abort the tree traversal and return true */
344 184988 : return expression_tree_walker(node, contain_subplans_walker, context);
345 : }
346 :
347 :
348 : /*****************************************************************************
349 : * Check clauses for mutable functions
350 : *****************************************************************************/
351 :
352 : /*
353 : * contain_mutable_functions
354 : * Recursively search for mutable functions within a clause.
355 : *
356 : * Returns true if any mutable function (or operator implemented by a
357 : * mutable function) is found. This test is needed so that we don't
358 : * mistakenly think that something like "WHERE random() < 0.5" can be treated
359 : * as a constant qualification.
360 : *
361 : * This will give the right answer only for clauses that have been put
362 : * through expression preprocessing. Callers outside the planner typically
363 : * should use contain_mutable_functions_after_planning() instead, for the
364 : * reasons given there.
365 : *
366 : * We will recursively look into Query nodes (i.e., SubLink sub-selects)
367 : * but not into SubPlans. See comments for contain_volatile_functions().
368 : */
369 : bool
370 166706 : contain_mutable_functions(Node *clause)
371 : {
372 166706 : return contain_mutable_functions_walker(clause, NULL);
373 : }
374 :
375 : static bool
376 122674 : contain_mutable_functions_checker(Oid func_id, void *context)
377 : {
378 122674 : return (func_volatile(func_id) != PROVOLATILE_IMMUTABLE);
379 : }
380 :
381 : static bool
382 428550 : contain_mutable_functions_walker(Node *node, void *context)
383 : {
384 428550 : if (node == NULL)
385 2280 : return false;
386 : /* Check for mutable functions in node itself */
387 426270 : if (check_functions_in_node(node, contain_mutable_functions_checker,
388 : context))
389 9418 : return true;
390 :
391 416852 : if (IsA(node, JsonConstructorExpr))
392 : {
393 0 : const JsonConstructorExpr *ctor = (JsonConstructorExpr *) node;
394 : ListCell *lc;
395 : bool is_jsonb;
396 :
397 0 : is_jsonb = ctor->returning->format->format_type == JS_FORMAT_JSONB;
398 :
399 : /*
400 : * Check argument_type => json[b] conversions specifically. We still
401 : * recurse to check 'args' below, but here we want to specifically
402 : * check whether or not the emitted clause would fail to be immutable
403 : * because of TimeZone, for example.
404 : */
405 0 : foreach(lc, ctor->args)
406 : {
407 0 : Oid typid = exprType(lfirst(lc));
408 :
409 0 : if (is_jsonb ?
410 0 : !to_jsonb_is_immutable(typid) :
411 0 : !to_json_is_immutable(typid))
412 0 : return true;
413 : }
414 :
415 : /* Check all subnodes */
416 : }
417 :
418 416852 : if (IsA(node, JsonExpr))
419 : {
420 234 : JsonExpr *jexpr = castNode(JsonExpr, node);
421 : Const *cnst;
422 :
423 234 : if (!IsA(jexpr->path_spec, Const))
424 0 : return true;
425 :
426 234 : cnst = castNode(Const, jexpr->path_spec);
427 :
428 : Assert(cnst->consttype == JSONPATHOID);
429 234 : if (cnst->constisnull)
430 0 : return false;
431 :
432 234 : if (jspIsMutable(DatumGetJsonPathP(cnst->constvalue),
433 : jexpr->passing_names, jexpr->passing_values))
434 162 : return true;
435 : }
436 :
437 416690 : if (IsA(node, SQLValueFunction))
438 : {
439 : /* all variants of SQLValueFunction are stable */
440 390 : return true;
441 : }
442 :
443 416300 : if (IsA(node, NextValueExpr))
444 : {
445 : /* NextValueExpr is volatile */
446 0 : return true;
447 : }
448 :
449 : /*
450 : * It should be safe to treat MinMaxExpr as immutable, because it will
451 : * depend on a non-cross-type btree comparison function, and those should
452 : * always be immutable. Treating XmlExpr as immutable is more dubious,
453 : * and treating CoerceToDomain as immutable is outright dangerous. But we
454 : * have done so historically, and changing this would probably cause more
455 : * problems than it would fix. In practice, if you have a non-immutable
456 : * domain constraint you are in for pain anyhow.
457 : */
458 :
459 : /* Recurse to check arguments */
460 416300 : if (IsA(node, Query))
461 : {
462 : /* Recurse into subselects */
463 0 : return query_tree_walker((Query *) node,
464 : contain_mutable_functions_walker,
465 : context, 0);
466 : }
467 416300 : return expression_tree_walker(node, contain_mutable_functions_walker,
468 : context);
469 : }
470 :
471 : /*
472 : * contain_mutable_functions_after_planning
473 : * Test whether given expression contains mutable functions.
474 : *
475 : * This is a wrapper for contain_mutable_functions() that is safe to use from
476 : * outside the planner. The difference is that it first runs the expression
477 : * through expression_planner(). There are two key reasons why we need that:
478 : *
479 : * First, function default arguments will get inserted, which may affect
480 : * volatility (consider "default now()").
481 : *
482 : * Second, inline-able functions will get inlined, which may allow us to
483 : * conclude that the function is really less volatile than it's marked.
484 : * As an example, polymorphic functions must be marked with the most volatile
485 : * behavior that they have for any input type, but once we inline the
486 : * function we may be able to conclude that it's not so volatile for the
487 : * particular input type we're dealing with.
488 : */
489 : bool
490 2294 : contain_mutable_functions_after_planning(Expr *expr)
491 : {
492 : /* We assume here that expression_planner() won't scribble on its input */
493 2294 : expr = expression_planner(expr);
494 :
495 : /* Now we can search for non-immutable functions */
496 2294 : return contain_mutable_functions((Node *) expr);
497 : }
498 :
499 :
500 : /*****************************************************************************
501 : * Check clauses for volatile functions
502 : *****************************************************************************/
503 :
504 : /*
505 : * contain_volatile_functions
506 : * Recursively search for volatile functions within a clause.
507 : *
508 : * Returns true if any volatile function (or operator implemented by a
509 : * volatile function) is found. This test prevents, for example,
510 : * invalid conversions of volatile expressions into indexscan quals.
511 : *
512 : * This will give the right answer only for clauses that have been put
513 : * through expression preprocessing. Callers outside the planner typically
514 : * should use contain_volatile_functions_after_planning() instead, for the
515 : * reasons given there.
516 : *
517 : * We will recursively look into Query nodes (i.e., SubLink sub-selects)
518 : * but not into SubPlans. This is a bit odd, but intentional. If we are
519 : * looking at a SubLink, we are probably deciding whether a query tree
520 : * transformation is safe, and a contained sub-select should affect that;
521 : * for example, duplicating a sub-select containing a volatile function
522 : * would be bad. However, once we've got to the stage of having SubPlans,
523 : * subsequent planning need not consider volatility within those, since
524 : * the executor won't change its evaluation rules for a SubPlan based on
525 : * volatility.
526 : *
527 : * For some node types, for example, RestrictInfo and PathTarget, we cache
528 : * whether we found any volatile functions or not and reuse that value in any
529 : * future checks for that node. All of the logic for determining if the
530 : * cached value should be set to VOLATILITY_NOVOLATILE or VOLATILITY_VOLATILE
531 : * belongs in this function. Any code which makes changes to these nodes
532 : * which could change the outcome this function must set the cached value back
533 : * to VOLATILITY_UNKNOWN. That allows this function to redetermine the
534 : * correct value during the next call, should we need to redetermine if the
535 : * node contains any volatile functions again in the future.
536 : */
537 : bool
538 2879088 : contain_volatile_functions(Node *clause)
539 : {
540 2879088 : return contain_volatile_functions_walker(clause, NULL);
541 : }
542 :
543 : static bool
544 729332 : contain_volatile_functions_checker(Oid func_id, void *context)
545 : {
546 729332 : return (func_volatile(func_id) == PROVOLATILE_VOLATILE);
547 : }
548 :
549 : static bool
550 6343722 : contain_volatile_functions_walker(Node *node, void *context)
551 : {
552 6343722 : if (node == NULL)
553 191792 : return false;
554 : /* Check for volatile functions in node itself */
555 6151930 : if (check_functions_in_node(node, contain_volatile_functions_checker,
556 : context))
557 1706 : return true;
558 :
559 6150224 : if (IsA(node, NextValueExpr))
560 : {
561 : /* NextValueExpr is volatile */
562 0 : return true;
563 : }
564 :
565 6150224 : if (IsA(node, RestrictInfo))
566 : {
567 1135562 : RestrictInfo *rinfo = (RestrictInfo *) node;
568 :
569 : /*
570 : * For RestrictInfo, check if we've checked the volatility of it
571 : * before. If so, we can just use the cached value and not bother
572 : * checking it again. Otherwise, check it and cache if whether we
573 : * found any volatile functions.
574 : */
575 1135562 : if (rinfo->has_volatile == VOLATILITY_NOVOLATILE)
576 706168 : return false;
577 429394 : else if (rinfo->has_volatile == VOLATILITY_VOLATILE)
578 8 : return true;
579 : else
580 : {
581 : bool hasvolatile;
582 :
583 429386 : hasvolatile = contain_volatile_functions_walker((Node *) rinfo->clause,
584 : context);
585 429386 : if (hasvolatile)
586 40 : rinfo->has_volatile = VOLATILITY_VOLATILE;
587 : else
588 429346 : rinfo->has_volatile = VOLATILITY_NOVOLATILE;
589 :
590 429386 : return hasvolatile;
591 : }
592 : }
593 :
594 5014662 : if (IsA(node, PathTarget))
595 : {
596 333592 : PathTarget *target = (PathTarget *) node;
597 :
598 : /*
599 : * We also do caching for PathTarget the same as we do above for
600 : * RestrictInfos.
601 : */
602 333592 : if (target->has_volatile_expr == VOLATILITY_NOVOLATILE)
603 280352 : return false;
604 53240 : else if (target->has_volatile_expr == VOLATILITY_VOLATILE)
605 0 : return true;
606 : else
607 : {
608 : bool hasvolatile;
609 :
610 53240 : hasvolatile = contain_volatile_functions_walker((Node *) target->exprs,
611 : context);
612 :
613 53240 : if (hasvolatile)
614 0 : target->has_volatile_expr = VOLATILITY_VOLATILE;
615 : else
616 53240 : target->has_volatile_expr = VOLATILITY_NOVOLATILE;
617 :
618 53240 : return hasvolatile;
619 : }
620 : }
621 :
622 : /*
623 : * See notes in contain_mutable_functions_walker about why we treat
624 : * MinMaxExpr, XmlExpr, and CoerceToDomain as immutable, while
625 : * SQLValueFunction is stable. Hence, none of them are of interest here.
626 : */
627 :
628 : /* Recurse to check arguments */
629 4681070 : if (IsA(node, Query))
630 : {
631 : /* Recurse into subselects */
632 6132 : return query_tree_walker((Query *) node,
633 : contain_volatile_functions_walker,
634 : context, 0);
635 : }
636 4674938 : return expression_tree_walker(node, contain_volatile_functions_walker,
637 : context);
638 : }
639 :
640 : /*
641 : * contain_volatile_functions_after_planning
642 : * Test whether given expression contains volatile functions.
643 : *
644 : * This is a wrapper for contain_volatile_functions() that is safe to use from
645 : * outside the planner. The difference is that it first runs the expression
646 : * through expression_planner(). There are two key reasons why we need that:
647 : *
648 : * First, function default arguments will get inserted, which may affect
649 : * volatility (consider "default random()").
650 : *
651 : * Second, inline-able functions will get inlined, which may allow us to
652 : * conclude that the function is really less volatile than it's marked.
653 : * As an example, polymorphic functions must be marked with the most volatile
654 : * behavior that they have for any input type, but once we inline the
655 : * function we may be able to conclude that it's not so volatile for the
656 : * particular input type we're dealing with.
657 : */
658 : bool
659 560 : contain_volatile_functions_after_planning(Expr *expr)
660 : {
661 : /* We assume here that expression_planner() won't scribble on its input */
662 560 : expr = expression_planner(expr);
663 :
664 : /* Now we can search for volatile functions */
665 560 : return contain_volatile_functions((Node *) expr);
666 : }
667 :
668 : /*
669 : * Special purpose version of contain_volatile_functions() for use in COPY:
670 : * ignore nextval(), but treat all other functions normally.
671 : */
672 : bool
673 252 : contain_volatile_functions_not_nextval(Node *clause)
674 : {
675 252 : return contain_volatile_functions_not_nextval_walker(clause, NULL);
676 : }
677 :
678 : static bool
679 64 : contain_volatile_functions_not_nextval_checker(Oid func_id, void *context)
680 : {
681 104 : return (func_id != F_NEXTVAL &&
682 40 : func_volatile(func_id) == PROVOLATILE_VOLATILE);
683 : }
684 :
685 : static bool
686 312 : contain_volatile_functions_not_nextval_walker(Node *node, void *context)
687 : {
688 312 : if (node == NULL)
689 0 : return false;
690 : /* Check for volatile functions in node itself */
691 312 : if (check_functions_in_node(node,
692 : contain_volatile_functions_not_nextval_checker,
693 : context))
694 6 : return true;
695 :
696 : /*
697 : * See notes in contain_mutable_functions_walker about why we treat
698 : * MinMaxExpr, XmlExpr, and CoerceToDomain as immutable, while
699 : * SQLValueFunction is stable. Hence, none of them are of interest here.
700 : * Also, since we're intentionally ignoring nextval(), presumably we
701 : * should ignore NextValueExpr.
702 : */
703 :
704 : /* Recurse to check arguments */
705 306 : if (IsA(node, Query))
706 : {
707 : /* Recurse into subselects */
708 0 : return query_tree_walker((Query *) node,
709 : contain_volatile_functions_not_nextval_walker,
710 : context, 0);
711 : }
712 306 : return expression_tree_walker(node,
713 : contain_volatile_functions_not_nextval_walker,
714 : context);
715 : }
716 :
717 :
718 : /*****************************************************************************
719 : * Check queries for parallel unsafe and/or restricted constructs
720 : *****************************************************************************/
721 :
722 : /*
723 : * max_parallel_hazard
724 : * Find the worst parallel-hazard level in the given query
725 : *
726 : * Returns the worst function hazard property (the earliest in this list:
727 : * PROPARALLEL_UNSAFE, PROPARALLEL_RESTRICTED, PROPARALLEL_SAFE) that can
728 : * be found in the given parsetree. We use this to find out whether the query
729 : * can be parallelized at all. The caller will also save the result in
730 : * PlannerGlobal so as to short-circuit checks of portions of the querytree
731 : * later, in the common case where everything is SAFE.
732 : */
733 : char
734 342840 : max_parallel_hazard(Query *parse)
735 : {
736 : max_parallel_hazard_context context;
737 :
738 342840 : context.max_hazard = PROPARALLEL_SAFE;
739 342840 : context.max_interesting = PROPARALLEL_UNSAFE;
740 342840 : context.safe_param_ids = NIL;
741 342840 : (void) max_parallel_hazard_walker((Node *) parse, &context);
742 342840 : return context.max_hazard;
743 : }
744 :
745 : /*
746 : * is_parallel_safe
747 : * Detect whether the given expr contains only parallel-safe functions
748 : *
749 : * root->glob->maxParallelHazard must previously have been set to the
750 : * result of max_parallel_hazard() on the whole query.
751 : */
752 : bool
753 2061516 : is_parallel_safe(PlannerInfo *root, Node *node)
754 : {
755 : max_parallel_hazard_context context;
756 : PlannerInfo *proot;
757 : ListCell *l;
758 :
759 : /*
760 : * Even if the original querytree contained nothing unsafe, we need to
761 : * search the expression if we have generated any PARAM_EXEC Params while
762 : * planning, because those are parallel-restricted and there might be one
763 : * in this expression. But otherwise we don't need to look.
764 : */
765 2061516 : if (root->glob->maxParallelHazard == PROPARALLEL_SAFE &&
766 1257738 : root->glob->paramExecTypes == NIL)
767 1226296 : return true;
768 : /* Else use max_parallel_hazard's search logic, but stop on RESTRICTED */
769 835220 : context.max_hazard = PROPARALLEL_SAFE;
770 835220 : context.max_interesting = PROPARALLEL_RESTRICTED;
771 835220 : context.safe_param_ids = NIL;
772 :
773 : /*
774 : * The params that refer to the same or parent query level are considered
775 : * parallel-safe. The idea is that we compute such params at Gather or
776 : * Gather Merge node and pass their value to workers.
777 : */
778 1991468 : for (proot = root; proot != NULL; proot = proot->parent_root)
779 : {
780 1214722 : foreach(l, proot->init_plans)
781 : {
782 58474 : SubPlan *initsubplan = (SubPlan *) lfirst(l);
783 :
784 58474 : context.safe_param_ids = list_concat(context.safe_param_ids,
785 58474 : initsubplan->setParam);
786 : }
787 : }
788 :
789 835220 : return !max_parallel_hazard_walker(node, &context);
790 : }
791 :
792 : /* core logic for all parallel-hazard checks */
793 : static bool
794 1462692 : max_parallel_hazard_test(char proparallel, max_parallel_hazard_context *context)
795 : {
796 1462692 : switch (proparallel)
797 : {
798 1193764 : case PROPARALLEL_SAFE:
799 : /* nothing to see here, move along */
800 1193764 : break;
801 180524 : case PROPARALLEL_RESTRICTED:
802 : /* increase max_hazard to RESTRICTED */
803 : Assert(context->max_hazard != PROPARALLEL_UNSAFE);
804 180524 : context->max_hazard = proparallel;
805 : /* done if we are not expecting any unsafe functions */
806 180524 : if (context->max_interesting == proparallel)
807 96452 : return true;
808 84072 : break;
809 88404 : case PROPARALLEL_UNSAFE:
810 88404 : context->max_hazard = proparallel;
811 : /* we're always done at the first unsafe construct */
812 88404 : return true;
813 0 : default:
814 0 : elog(ERROR, "unrecognized proparallel value \"%c\"", proparallel);
815 : break;
816 : }
817 1277836 : return false;
818 : }
819 :
820 : /* check_functions_in_node callback */
821 : static bool
822 1342082 : max_parallel_hazard_checker(Oid func_id, void *context)
823 : {
824 1342082 : return max_parallel_hazard_test(func_parallel(func_id),
825 : (max_parallel_hazard_context *) context);
826 : }
827 :
828 : static bool
829 18249490 : max_parallel_hazard_walker(Node *node, max_parallel_hazard_context *context)
830 : {
831 18249490 : if (node == NULL)
832 5071464 : return false;
833 :
834 : /* Check for hazardous functions in node itself */
835 13178026 : if (check_functions_in_node(node, max_parallel_hazard_checker,
836 : context))
837 115288 : return true;
838 :
839 : /*
840 : * It should be OK to treat MinMaxExpr as parallel-safe, since btree
841 : * opclass support functions are generally parallel-safe. XmlExpr is a
842 : * bit more dubious but we can probably get away with it. We err on the
843 : * side of caution by treating CoerceToDomain as parallel-restricted.
844 : * (Note: in principle that's wrong because a domain constraint could
845 : * contain a parallel-unsafe function; but useful constraints probably
846 : * never would have such, and assuming they do would cripple use of
847 : * parallel query in the presence of domain types.) SQLValueFunction
848 : * should be safe in all cases. NextValueExpr is parallel-unsafe.
849 : */
850 13062738 : if (IsA(node, CoerceToDomain))
851 : {
852 19482 : if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
853 6172 : return true;
854 : }
855 :
856 13043256 : else if (IsA(node, NextValueExpr))
857 : {
858 350 : if (max_parallel_hazard_test(PROPARALLEL_UNSAFE, context))
859 350 : return true;
860 : }
861 :
862 : /*
863 : * Treat window functions as parallel-restricted because we aren't sure
864 : * whether the input row ordering is fully deterministic, and the output
865 : * of window functions might vary across workers if not. (In some cases,
866 : * like where the window frame orders by a primary key, we could relax
867 : * this restriction. But it doesn't currently seem worth expending extra
868 : * effort to do so.)
869 : */
870 13042906 : else if (IsA(node, WindowFunc))
871 : {
872 5376 : if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
873 2392 : return true;
874 : }
875 :
876 : /*
877 : * As a notational convenience for callers, look through RestrictInfo.
878 : */
879 13037530 : else if (IsA(node, RestrictInfo))
880 : {
881 220086 : RestrictInfo *rinfo = (RestrictInfo *) node;
882 :
883 220086 : return max_parallel_hazard_walker((Node *) rinfo->clause, context);
884 : }
885 :
886 : /*
887 : * Really we should not see SubLink during a max_interesting == restricted
888 : * scan, but if we do, return true.
889 : */
890 12817444 : else if (IsA(node, SubLink))
891 : {
892 33058 : if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
893 0 : return true;
894 : }
895 :
896 : /*
897 : * Only parallel-safe SubPlans can be sent to workers. Within the
898 : * testexpr of the SubPlan, Params representing the output columns of the
899 : * subplan can be treated as parallel-safe, so temporarily add their IDs
900 : * to the safe_param_ids list while examining the testexpr.
901 : */
902 12784386 : else if (IsA(node, SubPlan))
903 : {
904 28274 : SubPlan *subplan = (SubPlan *) node;
905 : List *save_safe_param_ids;
906 :
907 56242 : if (!subplan->parallel_safe &&
908 27968 : max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
909 27968 : return true;
910 306 : save_safe_param_ids = context->safe_param_ids;
911 612 : context->safe_param_ids = list_concat_copy(context->safe_param_ids,
912 306 : subplan->paramIds);
913 306 : if (max_parallel_hazard_walker(subplan->testexpr, context))
914 6 : return true; /* no need to restore safe_param_ids */
915 300 : list_free(context->safe_param_ids);
916 300 : context->safe_param_ids = save_safe_param_ids;
917 : /* we must also check args, but no special Param treatment there */
918 300 : if (max_parallel_hazard_walker((Node *) subplan->args, context))
919 0 : return true;
920 : /* don't want to recurse normally, so we're done */
921 300 : return false;
922 : }
923 :
924 : /*
925 : * We can't pass Params to workers at the moment either, so they are also
926 : * parallel-restricted, unless they are PARAM_EXTERN Params or are
927 : * PARAM_EXEC Params listed in safe_param_ids, meaning they could be
928 : * either generated within workers or can be computed by the leader and
929 : * then their value can be passed to workers.
930 : */
931 12756112 : else if (IsA(node, Param))
932 : {
933 211152 : Param *param = (Param *) node;
934 :
935 211152 : if (param->paramkind == PARAM_EXTERN)
936 167136 : return false;
937 :
938 44016 : if (param->paramkind != PARAM_EXEC ||
939 42260 : !list_member_int(context->safe_param_ids, param->paramid))
940 : {
941 34376 : if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
942 32686 : return true;
943 : }
944 11330 : return false; /* nothing to recurse to */
945 : }
946 :
947 : /*
948 : * When we're first invoked on a completely unplanned tree, we must
949 : * recurse into subqueries so to as to locate parallel-unsafe constructs
950 : * anywhere in the tree.
951 : */
952 12544960 : else if (IsA(node, Query))
953 : {
954 417506 : Query *query = (Query *) node;
955 :
956 : /* SELECT FOR UPDATE/SHARE must be treated as unsafe */
957 417506 : if (query->rowMarks != NULL)
958 : {
959 1750 : context->max_hazard = PROPARALLEL_UNSAFE;
960 1750 : return true;
961 : }
962 :
963 : /* Recurse into subselects */
964 415756 : return query_tree_walker(query,
965 : max_parallel_hazard_walker,
966 : context, 0);
967 : }
968 :
969 : /* Recurse to check arguments */
970 12176806 : return expression_tree_walker(node,
971 : max_parallel_hazard_walker,
972 : context);
973 : }
974 :
975 :
976 : /*****************************************************************************
977 : * Check clauses for nonstrict functions
978 : *****************************************************************************/
979 :
980 : /*
981 : * contain_nonstrict_functions
982 : * Recursively search for nonstrict functions within a clause.
983 : *
984 : * Returns true if any nonstrict construct is found --- ie, anything that
985 : * could produce non-NULL output with a NULL input.
986 : *
987 : * The idea here is that the caller has verified that the expression contains
988 : * one or more Var or Param nodes (as appropriate for the caller's need), and
989 : * now wishes to prove that the expression result will be NULL if any of these
990 : * inputs is NULL. If we return false, then the proof succeeded.
991 : */
992 : bool
993 2050 : contain_nonstrict_functions(Node *clause)
994 : {
995 2050 : return contain_nonstrict_functions_walker(clause, NULL);
996 : }
997 :
998 : static bool
999 2170 : contain_nonstrict_functions_checker(Oid func_id, void *context)
1000 : {
1001 2170 : return !func_strict(func_id);
1002 : }
1003 :
1004 : static bool
1005 7326 : contain_nonstrict_functions_walker(Node *node, void *context)
1006 : {
1007 7326 : if (node == NULL)
1008 0 : return false;
1009 7326 : if (IsA(node, Aggref))
1010 : {
1011 : /* an aggregate could return non-null with null input */
1012 0 : return true;
1013 : }
1014 7326 : if (IsA(node, GroupingFunc))
1015 : {
1016 : /*
1017 : * A GroupingFunc doesn't evaluate its arguments, and therefore must
1018 : * be treated as nonstrict.
1019 : */
1020 0 : return true;
1021 : }
1022 7326 : if (IsA(node, WindowFunc))
1023 : {
1024 : /* a window function could return non-null with null input */
1025 0 : return true;
1026 : }
1027 7326 : if (IsA(node, SubscriptingRef))
1028 : {
1029 0 : SubscriptingRef *sbsref = (SubscriptingRef *) node;
1030 : const SubscriptRoutines *sbsroutines;
1031 :
1032 : /* Subscripting assignment is always presumed nonstrict */
1033 0 : if (sbsref->refassgnexpr != NULL)
1034 0 : return true;
1035 : /* Otherwise we must look up the subscripting support methods */
1036 0 : sbsroutines = getSubscriptingRoutines(sbsref->refcontainertype, NULL);
1037 0 : if (!(sbsroutines && sbsroutines->fetch_strict))
1038 0 : return true;
1039 : /* else fall through to check args */
1040 : }
1041 7326 : if (IsA(node, DistinctExpr))
1042 : {
1043 : /* IS DISTINCT FROM is inherently non-strict */
1044 0 : return true;
1045 : }
1046 7326 : if (IsA(node, NullIfExpr))
1047 : {
1048 : /* NULLIF is inherently non-strict */
1049 0 : return true;
1050 : }
1051 7326 : if (IsA(node, BoolExpr))
1052 : {
1053 18 : BoolExpr *expr = (BoolExpr *) node;
1054 :
1055 18 : switch (expr->boolop)
1056 : {
1057 18 : case AND_EXPR:
1058 : case OR_EXPR:
1059 : /* AND, OR are inherently non-strict */
1060 18 : return true;
1061 0 : default:
1062 0 : break;
1063 : }
1064 7308 : }
1065 7308 : if (IsA(node, SubLink))
1066 : {
1067 : /* In some cases a sublink might be strict, but in general not */
1068 12 : return true;
1069 : }
1070 7296 : if (IsA(node, SubPlan))
1071 0 : return true;
1072 7296 : if (IsA(node, AlternativeSubPlan))
1073 0 : return true;
1074 7296 : if (IsA(node, FieldStore))
1075 0 : return true;
1076 7296 : if (IsA(node, CoerceViaIO))
1077 : {
1078 : /*
1079 : * CoerceViaIO is strict regardless of whether the I/O functions are,
1080 : * so just go look at its argument; asking check_functions_in_node is
1081 : * useless expense and could deliver the wrong answer.
1082 : */
1083 1000 : return contain_nonstrict_functions_walker((Node *) ((CoerceViaIO *) node)->arg,
1084 : context);
1085 : }
1086 6296 : if (IsA(node, ArrayCoerceExpr))
1087 : {
1088 : /*
1089 : * ArrayCoerceExpr is strict at the array level, regardless of what
1090 : * the per-element expression is; so we should ignore elemexpr and
1091 : * recurse only into the arg.
1092 : */
1093 0 : return contain_nonstrict_functions_walker((Node *) ((ArrayCoerceExpr *) node)->arg,
1094 : context);
1095 : }
1096 6296 : if (IsA(node, CaseExpr))
1097 190 : return true;
1098 6106 : if (IsA(node, ArrayExpr))
1099 0 : return true;
1100 6106 : if (IsA(node, RowExpr))
1101 4 : return true;
1102 6102 : if (IsA(node, RowCompareExpr))
1103 0 : return true;
1104 6102 : if (IsA(node, CoalesceExpr))
1105 116 : return true;
1106 5986 : if (IsA(node, MinMaxExpr))
1107 60 : return true;
1108 5926 : if (IsA(node, XmlExpr))
1109 0 : return true;
1110 5926 : if (IsA(node, NullTest))
1111 12 : return true;
1112 5914 : if (IsA(node, BooleanTest))
1113 0 : return true;
1114 :
1115 : /* Check other function-containing nodes */
1116 5914 : if (check_functions_in_node(node, contain_nonstrict_functions_checker,
1117 : context))
1118 0 : return true;
1119 :
1120 5914 : return expression_tree_walker(node, contain_nonstrict_functions_walker,
1121 : context);
1122 : }
1123 :
1124 : /*****************************************************************************
1125 : * Check clauses for Params
1126 : *****************************************************************************/
1127 :
1128 : /*
1129 : * contain_exec_param
1130 : * Recursively search for PARAM_EXEC Params within a clause.
1131 : *
1132 : * Returns true if the clause contains any PARAM_EXEC Param with a paramid
1133 : * appearing in the given list of Param IDs. Does not descend into
1134 : * subqueries!
1135 : */
1136 : bool
1137 2744 : contain_exec_param(Node *clause, List *param_ids)
1138 : {
1139 2744 : return contain_exec_param_walker(clause, param_ids);
1140 : }
1141 :
1142 : static bool
1143 2954 : contain_exec_param_walker(Node *node, List *param_ids)
1144 : {
1145 2954 : if (node == NULL)
1146 18 : return false;
1147 2936 : if (IsA(node, Param))
1148 : {
1149 12 : Param *p = (Param *) node;
1150 :
1151 24 : if (p->paramkind == PARAM_EXEC &&
1152 12 : list_member_int(param_ids, p->paramid))
1153 12 : return true;
1154 : }
1155 2924 : return expression_tree_walker(node, contain_exec_param_walker, param_ids);
1156 : }
1157 :
1158 : /*****************************************************************************
1159 : * Check clauses for context-dependent nodes
1160 : *****************************************************************************/
1161 :
1162 : /*
1163 : * contain_context_dependent_node
1164 : * Recursively search for context-dependent nodes within a clause.
1165 : *
1166 : * CaseTestExpr nodes must appear directly within the corresponding CaseExpr,
1167 : * not nested within another one, or they'll see the wrong test value. If one
1168 : * appears "bare" in the arguments of a SQL function, then we can't inline the
1169 : * SQL function for fear of creating such a situation. The same applies for
1170 : * CaseTestExpr used within the elemexpr of an ArrayCoerceExpr.
1171 : *
1172 : * CoerceToDomainValue would have the same issue if domain CHECK expressions
1173 : * could get inlined into larger expressions, but presently that's impossible.
1174 : * Still, it might be allowed in future, or other node types with similar
1175 : * issues might get invented. So give this function a generic name, and set
1176 : * up the recursion state to allow multiple flag bits.
1177 : */
1178 : static bool
1179 19352 : contain_context_dependent_node(Node *clause)
1180 : {
1181 19352 : int flags = 0;
1182 :
1183 19352 : return contain_context_dependent_node_walker(clause, &flags);
1184 : }
1185 :
1186 : #define CCDN_CASETESTEXPR_OK 0x0001 /* CaseTestExpr okay here? */
1187 :
1188 : static bool
1189 41806 : contain_context_dependent_node_walker(Node *node, int *flags)
1190 : {
1191 41806 : if (node == NULL)
1192 8420 : return false;
1193 33386 : if (IsA(node, CaseTestExpr))
1194 6 : return !(*flags & CCDN_CASETESTEXPR_OK);
1195 33380 : else if (IsA(node, CaseExpr))
1196 : {
1197 0 : CaseExpr *caseexpr = (CaseExpr *) node;
1198 :
1199 : /*
1200 : * If this CASE doesn't have a test expression, then it doesn't create
1201 : * a context in which CaseTestExprs should appear, so just fall
1202 : * through and treat it as a generic expression node.
1203 : */
1204 0 : if (caseexpr->arg)
1205 : {
1206 0 : int save_flags = *flags;
1207 : bool res;
1208 :
1209 : /*
1210 : * Note: in principle, we could distinguish the various sub-parts
1211 : * of a CASE construct and set the flag bit only for some of them,
1212 : * since we are only expecting CaseTestExprs to appear in the
1213 : * "expr" subtree of the CaseWhen nodes. But it doesn't really
1214 : * seem worth any extra code. If there are any bare CaseTestExprs
1215 : * elsewhere in the CASE, something's wrong already.
1216 : */
1217 0 : *flags |= CCDN_CASETESTEXPR_OK;
1218 0 : res = expression_tree_walker(node,
1219 : contain_context_dependent_node_walker,
1220 : (void *) flags);
1221 0 : *flags = save_flags;
1222 0 : return res;
1223 : }
1224 : }
1225 33380 : else if (IsA(node, ArrayCoerceExpr))
1226 : {
1227 0 : ArrayCoerceExpr *ac = (ArrayCoerceExpr *) node;
1228 : int save_flags;
1229 : bool res;
1230 :
1231 : /* Check the array expression */
1232 0 : if (contain_context_dependent_node_walker((Node *) ac->arg, flags))
1233 0 : return true;
1234 :
1235 : /* Check the elemexpr, which is allowed to contain CaseTestExpr */
1236 0 : save_flags = *flags;
1237 0 : *flags |= CCDN_CASETESTEXPR_OK;
1238 0 : res = contain_context_dependent_node_walker((Node *) ac->elemexpr,
1239 : flags);
1240 0 : *flags = save_flags;
1241 0 : return res;
1242 : }
1243 33380 : return expression_tree_walker(node, contain_context_dependent_node_walker,
1244 : (void *) flags);
1245 : }
1246 :
1247 : /*****************************************************************************
1248 : * Check clauses for Vars passed to non-leakproof functions
1249 : *****************************************************************************/
1250 :
1251 : /*
1252 : * contain_leaked_vars
1253 : * Recursively scan a clause to discover whether it contains any Var
1254 : * nodes (of the current query level) that are passed as arguments to
1255 : * leaky functions.
1256 : *
1257 : * Returns true if the clause contains any non-leakproof functions that are
1258 : * passed Var nodes of the current query level, and which might therefore leak
1259 : * data. Such clauses must be applied after any lower-level security barrier
1260 : * clauses.
1261 : */
1262 : bool
1263 5276 : contain_leaked_vars(Node *clause)
1264 : {
1265 5276 : return contain_leaked_vars_walker(clause, NULL);
1266 : }
1267 :
1268 : static bool
1269 5254 : contain_leaked_vars_checker(Oid func_id, void *context)
1270 : {
1271 5254 : return !get_func_leakproof(func_id);
1272 : }
1273 :
1274 : static bool
1275 11266 : contain_leaked_vars_walker(Node *node, void *context)
1276 : {
1277 11266 : if (node == NULL)
1278 0 : return false;
1279 :
1280 11266 : switch (nodeTag(node))
1281 : {
1282 5946 : case T_Var:
1283 : case T_Const:
1284 : case T_Param:
1285 : case T_ArrayExpr:
1286 : case T_FieldSelect:
1287 : case T_FieldStore:
1288 : case T_NamedArgExpr:
1289 : case T_BoolExpr:
1290 : case T_RelabelType:
1291 : case T_CollateExpr:
1292 : case T_CaseExpr:
1293 : case T_CaseTestExpr:
1294 : case T_RowExpr:
1295 : case T_SQLValueFunction:
1296 : case T_NullTest:
1297 : case T_BooleanTest:
1298 : case T_NextValueExpr:
1299 : case T_List:
1300 :
1301 : /*
1302 : * We know these node types don't contain function calls; but
1303 : * something further down in the node tree might.
1304 : */
1305 5946 : break;
1306 :
1307 5254 : case T_FuncExpr:
1308 : case T_OpExpr:
1309 : case T_DistinctExpr:
1310 : case T_NullIfExpr:
1311 : case T_ScalarArrayOpExpr:
1312 : case T_CoerceViaIO:
1313 : case T_ArrayCoerceExpr:
1314 :
1315 : /*
1316 : * If node contains a leaky function call, and there's any Var
1317 : * underneath it, reject.
1318 : */
1319 5254 : if (check_functions_in_node(node, contain_leaked_vars_checker,
1320 2216 : context) &&
1321 2216 : contain_var_clause(node))
1322 2160 : return true;
1323 3094 : break;
1324 :
1325 0 : case T_SubscriptingRef:
1326 : {
1327 0 : SubscriptingRef *sbsref = (SubscriptingRef *) node;
1328 : const SubscriptRoutines *sbsroutines;
1329 :
1330 : /* Consult the subscripting support method info */
1331 0 : sbsroutines = getSubscriptingRoutines(sbsref->refcontainertype,
1332 : NULL);
1333 0 : if (!sbsroutines ||
1334 0 : !(sbsref->refassgnexpr != NULL ?
1335 0 : sbsroutines->store_leakproof :
1336 0 : sbsroutines->fetch_leakproof))
1337 : {
1338 : /* Node is leaky, so reject if it contains Vars */
1339 0 : if (contain_var_clause(node))
1340 0 : return true;
1341 : }
1342 : }
1343 0 : break;
1344 :
1345 0 : case T_RowCompareExpr:
1346 : {
1347 : /*
1348 : * It's worth special-casing this because a leaky comparison
1349 : * function only compromises one pair of row elements, which
1350 : * might not contain Vars while others do.
1351 : */
1352 0 : RowCompareExpr *rcexpr = (RowCompareExpr *) node;
1353 : ListCell *opid;
1354 : ListCell *larg;
1355 : ListCell *rarg;
1356 :
1357 0 : forthree(opid, rcexpr->opnos,
1358 : larg, rcexpr->largs,
1359 : rarg, rcexpr->rargs)
1360 : {
1361 0 : Oid funcid = get_opcode(lfirst_oid(opid));
1362 :
1363 0 : if (!get_func_leakproof(funcid) &&
1364 0 : (contain_var_clause((Node *) lfirst(larg)) ||
1365 0 : contain_var_clause((Node *) lfirst(rarg))))
1366 0 : return true;
1367 : }
1368 : }
1369 0 : break;
1370 :
1371 0 : case T_MinMaxExpr:
1372 : {
1373 : /*
1374 : * MinMaxExpr is leakproof if the comparison function it calls
1375 : * is leakproof.
1376 : */
1377 0 : MinMaxExpr *minmaxexpr = (MinMaxExpr *) node;
1378 : TypeCacheEntry *typentry;
1379 : bool leakproof;
1380 :
1381 : /* Look up the btree comparison function for the datatype */
1382 0 : typentry = lookup_type_cache(minmaxexpr->minmaxtype,
1383 : TYPECACHE_CMP_PROC);
1384 0 : if (OidIsValid(typentry->cmp_proc))
1385 0 : leakproof = get_func_leakproof(typentry->cmp_proc);
1386 : else
1387 : {
1388 : /*
1389 : * The executor will throw an error, but here we just
1390 : * treat the missing function as leaky.
1391 : */
1392 0 : leakproof = false;
1393 : }
1394 :
1395 0 : if (!leakproof &&
1396 0 : contain_var_clause((Node *) minmaxexpr->args))
1397 0 : return true;
1398 : }
1399 0 : break;
1400 :
1401 42 : case T_CurrentOfExpr:
1402 :
1403 : /*
1404 : * WHERE CURRENT OF doesn't contain leaky function calls.
1405 : * Moreover, it is essential that this is considered non-leaky,
1406 : * since the planner must always generate a TID scan when CURRENT
1407 : * OF is present -- cf. cost_tidscan.
1408 : */
1409 42 : return false;
1410 :
1411 24 : default:
1412 :
1413 : /*
1414 : * If we don't recognize the node tag, assume it might be leaky.
1415 : * This prevents an unexpected security hole if someone adds a new
1416 : * node type that can call a function.
1417 : */
1418 24 : return true;
1419 : }
1420 9040 : return expression_tree_walker(node, contain_leaked_vars_walker,
1421 : context);
1422 : }
1423 :
1424 : /*
1425 : * find_nonnullable_rels
1426 : * Determine which base rels are forced nonnullable by given clause.
1427 : *
1428 : * Returns the set of all Relids that are referenced in the clause in such
1429 : * a way that the clause cannot possibly return TRUE if any of these Relids
1430 : * is an all-NULL row. (It is OK to err on the side of conservatism; hence
1431 : * the analysis here is simplistic.)
1432 : *
1433 : * The semantics here are subtly different from contain_nonstrict_functions:
1434 : * that function is concerned with NULL results from arbitrary expressions,
1435 : * but here we assume that the input is a Boolean expression, and wish to
1436 : * see if NULL inputs will provably cause a FALSE-or-NULL result. We expect
1437 : * the expression to have been AND/OR flattened and converted to implicit-AND
1438 : * format.
1439 : *
1440 : * Note: this function is largely duplicative of find_nonnullable_vars().
1441 : * The reason not to simplify this function into a thin wrapper around
1442 : * find_nonnullable_vars() is that the tested conditions really are different:
1443 : * a clause like "t1.v1 IS NOT NULL OR t1.v2 IS NOT NULL" does not prove
1444 : * that either v1 or v2 can't be NULL, but it does prove that the t1 row
1445 : * as a whole can't be all-NULL. Also, the behavior for PHVs is different.
1446 : *
1447 : * top_level is true while scanning top-level AND/OR structure; here, showing
1448 : * the result is either FALSE or NULL is good enough. top_level is false when
1449 : * we have descended below a NOT or a strict function: now we must be able to
1450 : * prove that the subexpression goes to NULL.
1451 : *
1452 : * We don't use expression_tree_walker here because we don't want to descend
1453 : * through very many kinds of nodes; only the ones we can be sure are strict.
1454 : */
1455 : Relids
1456 89010 : find_nonnullable_rels(Node *clause)
1457 : {
1458 89010 : return find_nonnullable_rels_walker(clause, true);
1459 : }
1460 :
1461 : static Relids
1462 579564 : find_nonnullable_rels_walker(Node *node, bool top_level)
1463 : {
1464 579564 : Relids result = NULL;
1465 : ListCell *l;
1466 :
1467 579564 : if (node == NULL)
1468 5334 : return NULL;
1469 574230 : if (IsA(node, Var))
1470 : {
1471 184604 : Var *var = (Var *) node;
1472 :
1473 184604 : if (var->varlevelsup == 0)
1474 184604 : result = bms_make_singleton(var->varno);
1475 : }
1476 389626 : else if (IsA(node, List))
1477 : {
1478 : /*
1479 : * At top level, we are examining an implicit-AND list: if any of the
1480 : * arms produces FALSE-or-NULL then the result is FALSE-or-NULL. If
1481 : * not at top level, we are examining the arguments of a strict
1482 : * function: if any of them produce NULL then the result of the
1483 : * function must be NULL. So in both cases, the set of nonnullable
1484 : * rels is the union of those found in the arms, and we pass down the
1485 : * top_level flag unmodified.
1486 : */
1487 562794 : foreach(l, (List *) node)
1488 : {
1489 357482 : result = bms_join(result,
1490 357482 : find_nonnullable_rels_walker(lfirst(l),
1491 : top_level));
1492 : }
1493 : }
1494 184314 : else if (IsA(node, FuncExpr))
1495 : {
1496 6332 : FuncExpr *expr = (FuncExpr *) node;
1497 :
1498 6332 : if (func_strict(expr->funcid))
1499 6164 : result = find_nonnullable_rels_walker((Node *) expr->args, false);
1500 : }
1501 177982 : else if (IsA(node, OpExpr))
1502 : {
1503 105052 : OpExpr *expr = (OpExpr *) node;
1504 :
1505 105052 : set_opfuncid(expr);
1506 105052 : if (func_strict(expr->opfuncid))
1507 105052 : result = find_nonnullable_rels_walker((Node *) expr->args, false);
1508 : }
1509 72930 : else if (IsA(node, ScalarArrayOpExpr))
1510 : {
1511 7548 : ScalarArrayOpExpr *expr = (ScalarArrayOpExpr *) node;
1512 :
1513 7548 : if (is_strict_saop(expr, true))
1514 7548 : result = find_nonnullable_rels_walker((Node *) expr->args, false);
1515 : }
1516 65382 : else if (IsA(node, BoolExpr))
1517 : {
1518 6172 : BoolExpr *expr = (BoolExpr *) node;
1519 :
1520 6172 : switch (expr->boolop)
1521 : {
1522 402 : case AND_EXPR:
1523 : /* At top level we can just recurse (to the List case) */
1524 402 : if (top_level)
1525 : {
1526 402 : result = find_nonnullable_rels_walker((Node *) expr->args,
1527 : top_level);
1528 402 : break;
1529 : }
1530 :
1531 : /*
1532 : * Below top level, even if one arm produces NULL, the result
1533 : * could be FALSE (hence not NULL). However, if *all* the
1534 : * arms produce NULL then the result is NULL, so we can take
1535 : * the intersection of the sets of nonnullable rels, just as
1536 : * for OR. Fall through to share code.
1537 : */
1538 : /* FALL THRU */
1539 : case OR_EXPR:
1540 :
1541 : /*
1542 : * OR is strict if all of its arms are, so we can take the
1543 : * intersection of the sets of nonnullable rels for each arm.
1544 : * This works for both values of top_level.
1545 : */
1546 7398 : foreach(l, expr->args)
1547 : {
1548 : Relids subresult;
1549 :
1550 6538 : subresult = find_nonnullable_rels_walker(lfirst(l),
1551 : top_level);
1552 6538 : if (result == NULL) /* first subresult? */
1553 3300 : result = subresult;
1554 : else
1555 3238 : result = bms_int_members(result, subresult);
1556 :
1557 : /*
1558 : * If the intersection is empty, we can stop looking. This
1559 : * also justifies the test for first-subresult above.
1560 : */
1561 6538 : if (bms_is_empty(result))
1562 2440 : break;
1563 : }
1564 3300 : break;
1565 2470 : case NOT_EXPR:
1566 : /* NOT will return null if its arg is null */
1567 2470 : result = find_nonnullable_rels_walker((Node *) expr->args,
1568 : false);
1569 2470 : break;
1570 0 : default:
1571 0 : elog(ERROR, "unrecognized boolop: %d", (int) expr->boolop);
1572 : break;
1573 : }
1574 : }
1575 59210 : else if (IsA(node, RelabelType))
1576 : {
1577 1530 : RelabelType *expr = (RelabelType *) node;
1578 :
1579 1530 : result = find_nonnullable_rels_walker((Node *) expr->arg, top_level);
1580 : }
1581 57680 : else if (IsA(node, CoerceViaIO))
1582 : {
1583 : /* not clear this is useful, but it can't hurt */
1584 138 : CoerceViaIO *expr = (CoerceViaIO *) node;
1585 :
1586 138 : result = find_nonnullable_rels_walker((Node *) expr->arg, top_level);
1587 : }
1588 57542 : else if (IsA(node, ArrayCoerceExpr))
1589 : {
1590 : /* ArrayCoerceExpr is strict at the array level; ignore elemexpr */
1591 0 : ArrayCoerceExpr *expr = (ArrayCoerceExpr *) node;
1592 :
1593 0 : result = find_nonnullable_rels_walker((Node *) expr->arg, top_level);
1594 : }
1595 57542 : else if (IsA(node, ConvertRowtypeExpr))
1596 : {
1597 : /* not clear this is useful, but it can't hurt */
1598 0 : ConvertRowtypeExpr *expr = (ConvertRowtypeExpr *) node;
1599 :
1600 0 : result = find_nonnullable_rels_walker((Node *) expr->arg, top_level);
1601 : }
1602 57542 : else if (IsA(node, CollateExpr))
1603 : {
1604 0 : CollateExpr *expr = (CollateExpr *) node;
1605 :
1606 0 : result = find_nonnullable_rels_walker((Node *) expr->arg, top_level);
1607 : }
1608 57542 : else if (IsA(node, NullTest))
1609 : {
1610 : /* IS NOT NULL can be considered strict, but only at top level */
1611 4322 : NullTest *expr = (NullTest *) node;
1612 :
1613 4322 : if (top_level && expr->nulltesttype == IS_NOT_NULL && !expr->argisrow)
1614 2666 : result = find_nonnullable_rels_walker((Node *) expr->arg, false);
1615 : }
1616 53220 : else if (IsA(node, BooleanTest))
1617 : {
1618 : /* Boolean tests that reject NULL are strict at top level */
1619 58 : BooleanTest *expr = (BooleanTest *) node;
1620 :
1621 58 : if (top_level &&
1622 58 : (expr->booltesttype == IS_TRUE ||
1623 58 : expr->booltesttype == IS_FALSE ||
1624 6 : expr->booltesttype == IS_NOT_UNKNOWN))
1625 52 : result = find_nonnullable_rels_walker((Node *) expr->arg, false);
1626 : }
1627 53162 : else if (IsA(node, SubPlan))
1628 : {
1629 86 : SubPlan *splan = (SubPlan *) node;
1630 :
1631 : /*
1632 : * For some types of SubPlan, we can infer strictness from Vars in the
1633 : * testexpr (the LHS of the original SubLink).
1634 : *
1635 : * For ANY_SUBLINK, if the subquery produces zero rows, the result is
1636 : * always FALSE. If the subquery produces more than one row, the
1637 : * per-row results of the testexpr are combined using OR semantics.
1638 : * Hence ANY_SUBLINK can be strict only at top level, but there it's
1639 : * as strict as the testexpr is.
1640 : *
1641 : * For ROWCOMPARE_SUBLINK, if the subquery produces zero rows, the
1642 : * result is always NULL. Otherwise, the result is as strict as the
1643 : * testexpr is. So we can check regardless of top_level.
1644 : *
1645 : * We can't prove anything for other sublink types (in particular,
1646 : * note that ALL_SUBLINK will return TRUE if the subquery is empty).
1647 : */
1648 86 : if ((top_level && splan->subLinkType == ANY_SUBLINK) ||
1649 56 : splan->subLinkType == ROWCOMPARE_SUBLINK)
1650 30 : result = find_nonnullable_rels_walker(splan->testexpr, top_level);
1651 : }
1652 53076 : else if (IsA(node, PlaceHolderVar))
1653 : {
1654 482 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
1655 :
1656 : /*
1657 : * If the contained expression forces any rels non-nullable, so does
1658 : * the PHV.
1659 : */
1660 482 : result = find_nonnullable_rels_walker((Node *) phv->phexpr, top_level);
1661 :
1662 : /*
1663 : * If the PHV's syntactic scope is exactly one rel, it will be forced
1664 : * to be evaluated at that rel, and so it will behave like a Var of
1665 : * that rel: if the rel's entire output goes to null, so will the PHV.
1666 : * (If the syntactic scope is a join, we know that the PHV will go to
1667 : * null if the whole join does; but that is AND semantics while we
1668 : * need OR semantics for find_nonnullable_rels' result, so we can't do
1669 : * anything with the knowledge.)
1670 : */
1671 964 : if (phv->phlevelsup == 0 &&
1672 482 : bms_membership(phv->phrels) == BMS_SINGLETON)
1673 296 : result = bms_add_members(result, phv->phrels);
1674 : }
1675 574230 : return result;
1676 : }
1677 :
1678 : /*
1679 : * find_nonnullable_vars
1680 : * Determine which Vars are forced nonnullable by given clause.
1681 : *
1682 : * Returns the set of all level-zero Vars that are referenced in the clause in
1683 : * such a way that the clause cannot possibly return TRUE if any of these Vars
1684 : * is NULL. (It is OK to err on the side of conservatism; hence the analysis
1685 : * here is simplistic.)
1686 : *
1687 : * The semantics here are subtly different from contain_nonstrict_functions:
1688 : * that function is concerned with NULL results from arbitrary expressions,
1689 : * but here we assume that the input is a Boolean expression, and wish to
1690 : * see if NULL inputs will provably cause a FALSE-or-NULL result. We expect
1691 : * the expression to have been AND/OR flattened and converted to implicit-AND
1692 : * format.
1693 : *
1694 : * Attnos of the identified Vars are returned in a multibitmapset (a List of
1695 : * Bitmapsets). List indexes correspond to relids (varnos), while the per-rel
1696 : * Bitmapsets hold varattnos offset by FirstLowInvalidHeapAttributeNumber.
1697 : *
1698 : * top_level is true while scanning top-level AND/OR structure; here, showing
1699 : * the result is either FALSE or NULL is good enough. top_level is false when
1700 : * we have descended below a NOT or a strict function: now we must be able to
1701 : * prove that the subexpression goes to NULL.
1702 : *
1703 : * We don't use expression_tree_walker here because we don't want to descend
1704 : * through very many kinds of nodes; only the ones we can be sure are strict.
1705 : */
1706 : List *
1707 39926 : find_nonnullable_vars(Node *clause)
1708 : {
1709 39926 : return find_nonnullable_vars_walker(clause, true);
1710 : }
1711 :
1712 : static List *
1713 254594 : find_nonnullable_vars_walker(Node *node, bool top_level)
1714 : {
1715 254594 : List *result = NIL;
1716 : ListCell *l;
1717 :
1718 254594 : if (node == NULL)
1719 470 : return NIL;
1720 254124 : if (IsA(node, Var))
1721 : {
1722 94298 : Var *var = (Var *) node;
1723 :
1724 94298 : if (var->varlevelsup == 0)
1725 94298 : result = mbms_add_member(result,
1726 : var->varno,
1727 94298 : var->varattno - FirstLowInvalidHeapAttributeNumber);
1728 : }
1729 159826 : else if (IsA(node, List))
1730 : {
1731 : /*
1732 : * At top level, we are examining an implicit-AND list: if any of the
1733 : * arms produces FALSE-or-NULL then the result is FALSE-or-NULL. If
1734 : * not at top level, we are examining the arguments of a strict
1735 : * function: if any of them produce NULL then the result of the
1736 : * function must be NULL. So in both cases, the set of nonnullable
1737 : * vars is the union of those found in the arms, and we pass down the
1738 : * top_level flag unmodified.
1739 : */
1740 252736 : foreach(l, (List *) node)
1741 : {
1742 159702 : result = mbms_add_members(result,
1743 159702 : find_nonnullable_vars_walker(lfirst(l),
1744 : top_level));
1745 : }
1746 : }
1747 66792 : else if (IsA(node, FuncExpr))
1748 : {
1749 372 : FuncExpr *expr = (FuncExpr *) node;
1750 :
1751 372 : if (func_strict(expr->funcid))
1752 372 : result = find_nonnullable_vars_walker((Node *) expr->args, false);
1753 : }
1754 66420 : else if (IsA(node, OpExpr))
1755 : {
1756 51598 : OpExpr *expr = (OpExpr *) node;
1757 :
1758 51598 : set_opfuncid(expr);
1759 51598 : if (func_strict(expr->opfuncid))
1760 51598 : result = find_nonnullable_vars_walker((Node *) expr->args, false);
1761 : }
1762 14822 : else if (IsA(node, ScalarArrayOpExpr))
1763 : {
1764 1548 : ScalarArrayOpExpr *expr = (ScalarArrayOpExpr *) node;
1765 :
1766 1548 : if (is_strict_saop(expr, true))
1767 1548 : result = find_nonnullable_vars_walker((Node *) expr->args, false);
1768 : }
1769 13274 : else if (IsA(node, BoolExpr))
1770 : {
1771 360 : BoolExpr *expr = (BoolExpr *) node;
1772 :
1773 360 : switch (expr->boolop)
1774 : {
1775 0 : case AND_EXPR:
1776 :
1777 : /*
1778 : * At top level we can just recurse (to the List case), since
1779 : * the result should be the union of what we can prove in each
1780 : * arm.
1781 : */
1782 0 : if (top_level)
1783 : {
1784 0 : result = find_nonnullable_vars_walker((Node *) expr->args,
1785 : top_level);
1786 0 : break;
1787 : }
1788 :
1789 : /*
1790 : * Below top level, even if one arm produces NULL, the result
1791 : * could be FALSE (hence not NULL). However, if *all* the
1792 : * arms produce NULL then the result is NULL, so we can take
1793 : * the intersection of the sets of nonnullable vars, just as
1794 : * for OR. Fall through to share code.
1795 : */
1796 : /* FALL THRU */
1797 : case OR_EXPR:
1798 :
1799 : /*
1800 : * OR is strict if all of its arms are, so we can take the
1801 : * intersection of the sets of nonnullable vars for each arm.
1802 : * This works for both values of top_level.
1803 : */
1804 760 : foreach(l, expr->args)
1805 : {
1806 : List *subresult;
1807 :
1808 628 : subresult = find_nonnullable_vars_walker(lfirst(l),
1809 : top_level);
1810 628 : if (result == NIL) /* first subresult? */
1811 300 : result = subresult;
1812 : else
1813 328 : result = mbms_int_members(result, subresult);
1814 :
1815 : /*
1816 : * If the intersection is empty, we can stop looking. This
1817 : * also justifies the test for first-subresult above.
1818 : */
1819 628 : if (result == NIL)
1820 168 : break;
1821 : }
1822 300 : break;
1823 60 : case NOT_EXPR:
1824 : /* NOT will return null if its arg is null */
1825 60 : result = find_nonnullable_vars_walker((Node *) expr->args,
1826 : false);
1827 60 : break;
1828 0 : default:
1829 0 : elog(ERROR, "unrecognized boolop: %d", (int) expr->boolop);
1830 : break;
1831 : }
1832 : }
1833 12914 : else if (IsA(node, RelabelType))
1834 : {
1835 538 : RelabelType *expr = (RelabelType *) node;
1836 :
1837 538 : result = find_nonnullable_vars_walker((Node *) expr->arg, top_level);
1838 : }
1839 12376 : else if (IsA(node, CoerceViaIO))
1840 : {
1841 : /* not clear this is useful, but it can't hurt */
1842 54 : CoerceViaIO *expr = (CoerceViaIO *) node;
1843 :
1844 54 : result = find_nonnullable_vars_walker((Node *) expr->arg, false);
1845 : }
1846 12322 : else if (IsA(node, ArrayCoerceExpr))
1847 : {
1848 : /* ArrayCoerceExpr is strict at the array level; ignore elemexpr */
1849 0 : ArrayCoerceExpr *expr = (ArrayCoerceExpr *) node;
1850 :
1851 0 : result = find_nonnullable_vars_walker((Node *) expr->arg, top_level);
1852 : }
1853 12322 : else if (IsA(node, ConvertRowtypeExpr))
1854 : {
1855 : /* not clear this is useful, but it can't hurt */
1856 0 : ConvertRowtypeExpr *expr = (ConvertRowtypeExpr *) node;
1857 :
1858 0 : result = find_nonnullable_vars_walker((Node *) expr->arg, top_level);
1859 : }
1860 12322 : else if (IsA(node, CollateExpr))
1861 : {
1862 0 : CollateExpr *expr = (CollateExpr *) node;
1863 :
1864 0 : result = find_nonnullable_vars_walker((Node *) expr->arg, top_level);
1865 : }
1866 12322 : else if (IsA(node, NullTest))
1867 : {
1868 : /* IS NOT NULL can be considered strict, but only at top level */
1869 288 : NullTest *expr = (NullTest *) node;
1870 :
1871 288 : if (top_level && expr->nulltesttype == IS_NOT_NULL && !expr->argisrow)
1872 102 : result = find_nonnullable_vars_walker((Node *) expr->arg, false);
1873 : }
1874 12034 : else if (IsA(node, BooleanTest))
1875 : {
1876 : /* Boolean tests that reject NULL are strict at top level */
1877 0 : BooleanTest *expr = (BooleanTest *) node;
1878 :
1879 0 : if (top_level &&
1880 0 : (expr->booltesttype == IS_TRUE ||
1881 0 : expr->booltesttype == IS_FALSE ||
1882 0 : expr->booltesttype == IS_NOT_UNKNOWN))
1883 0 : result = find_nonnullable_vars_walker((Node *) expr->arg, false);
1884 : }
1885 12034 : else if (IsA(node, SubPlan))
1886 : {
1887 12 : SubPlan *splan = (SubPlan *) node;
1888 :
1889 : /* See analysis in find_nonnullable_rels_walker */
1890 12 : if ((top_level && splan->subLinkType == ANY_SUBLINK) ||
1891 0 : splan->subLinkType == ROWCOMPARE_SUBLINK)
1892 12 : result = find_nonnullable_vars_walker(splan->testexpr, top_level);
1893 : }
1894 12022 : else if (IsA(node, PlaceHolderVar))
1895 : {
1896 54 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
1897 :
1898 54 : result = find_nonnullable_vars_walker((Node *) phv->phexpr, top_level);
1899 : }
1900 254124 : return result;
1901 : }
1902 :
1903 : /*
1904 : * find_forced_null_vars
1905 : * Determine which Vars must be NULL for the given clause to return TRUE.
1906 : *
1907 : * This is the complement of find_nonnullable_vars: find the level-zero Vars
1908 : * that must be NULL for the clause to return TRUE. (It is OK to err on the
1909 : * side of conservatism; hence the analysis here is simplistic. In fact,
1910 : * we only detect simple "var IS NULL" tests at the top level.)
1911 : *
1912 : * As with find_nonnullable_vars, we return the varattnos of the identified
1913 : * Vars in a multibitmapset.
1914 : */
1915 : List *
1916 107092 : find_forced_null_vars(Node *node)
1917 : {
1918 107092 : List *result = NIL;
1919 : Var *var;
1920 : ListCell *l;
1921 :
1922 107092 : if (node == NULL)
1923 4778 : return NIL;
1924 : /* Check single-clause cases using subroutine */
1925 102314 : var = find_forced_null_var(node);
1926 102314 : if (var)
1927 : {
1928 1194 : result = mbms_add_member(result,
1929 : var->varno,
1930 1194 : var->varattno - FirstLowInvalidHeapAttributeNumber);
1931 : }
1932 : /* Otherwise, handle AND-conditions */
1933 101120 : else if (IsA(node, List))
1934 : {
1935 : /*
1936 : * At top level, we are examining an implicit-AND list: if any of the
1937 : * arms produces FALSE-or-NULL then the result is FALSE-or-NULL.
1938 : */
1939 102314 : foreach(l, (List *) node)
1940 : {
1941 62330 : result = mbms_add_members(result,
1942 62330 : find_forced_null_vars((Node *) lfirst(l)));
1943 : }
1944 : }
1945 61136 : else if (IsA(node, BoolExpr))
1946 : {
1947 4564 : BoolExpr *expr = (BoolExpr *) node;
1948 :
1949 : /*
1950 : * We don't bother considering the OR case, because it's fairly
1951 : * unlikely anyone would write "v1 IS NULL OR v1 IS NULL". Likewise,
1952 : * the NOT case isn't worth expending code on.
1953 : */
1954 4564 : if (expr->boolop == AND_EXPR)
1955 : {
1956 : /* At top level we can just recurse (to the List case) */
1957 0 : result = find_forced_null_vars((Node *) expr->args);
1958 : }
1959 : }
1960 102314 : return result;
1961 : }
1962 :
1963 : /*
1964 : * find_forced_null_var
1965 : * Return the Var forced null by the given clause, or NULL if it's
1966 : * not an IS NULL-type clause. For success, the clause must enforce
1967 : * *only* nullness of the particular Var, not any other conditions.
1968 : *
1969 : * This is just the single-clause case of find_forced_null_vars(), without
1970 : * any allowance for AND conditions. It's used by initsplan.c on individual
1971 : * qual clauses. The reason for not just applying find_forced_null_vars()
1972 : * is that if an AND of an IS NULL clause with something else were to somehow
1973 : * survive AND/OR flattening, initsplan.c might get fooled into discarding
1974 : * the whole clause when only the IS NULL part of it had been proved redundant.
1975 : */
1976 : Var *
1977 531224 : find_forced_null_var(Node *node)
1978 : {
1979 531224 : if (node == NULL)
1980 0 : return NULL;
1981 531224 : if (IsA(node, NullTest))
1982 : {
1983 : /* check for var IS NULL */
1984 10278 : NullTest *expr = (NullTest *) node;
1985 :
1986 10278 : if (expr->nulltesttype == IS_NULL && !expr->argisrow)
1987 : {
1988 3770 : Var *var = (Var *) expr->arg;
1989 :
1990 3770 : if (var && IsA(var, Var) &&
1991 3656 : var->varlevelsup == 0)
1992 3656 : return var;
1993 : }
1994 : }
1995 520946 : else if (IsA(node, BooleanTest))
1996 : {
1997 : /* var IS UNKNOWN is equivalent to var IS NULL */
1998 500 : BooleanTest *expr = (BooleanTest *) node;
1999 :
2000 500 : if (expr->booltesttype == IS_UNKNOWN)
2001 : {
2002 42 : Var *var = (Var *) expr->arg;
2003 :
2004 42 : if (var && IsA(var, Var) &&
2005 42 : var->varlevelsup == 0)
2006 42 : return var;
2007 : }
2008 : }
2009 527526 : return NULL;
2010 : }
2011 :
2012 : /*
2013 : * Can we treat a ScalarArrayOpExpr as strict?
2014 : *
2015 : * If "falseOK" is true, then a "false" result can be considered strict,
2016 : * else we need to guarantee an actual NULL result for NULL input.
2017 : *
2018 : * "foo op ALL array" is strict if the op is strict *and* we can prove
2019 : * that the array input isn't an empty array. We can check that
2020 : * for the cases of an array constant and an ARRAY[] construct.
2021 : *
2022 : * "foo op ANY array" is strict in the falseOK sense if the op is strict.
2023 : * If not falseOK, the test is the same as for "foo op ALL array".
2024 : */
2025 : static bool
2026 9096 : is_strict_saop(ScalarArrayOpExpr *expr, bool falseOK)
2027 : {
2028 : Node *rightop;
2029 :
2030 : /* The contained operator must be strict. */
2031 9096 : set_sa_opfuncid(expr);
2032 9096 : if (!func_strict(expr->opfuncid))
2033 0 : return false;
2034 : /* If ANY and falseOK, that's all we need to check. */
2035 9096 : if (expr->useOr && falseOK)
2036 8984 : return true;
2037 : /* Else, we have to see if the array is provably non-empty. */
2038 : Assert(list_length(expr->args) == 2);
2039 112 : rightop = (Node *) lsecond(expr->args);
2040 112 : if (rightop && IsA(rightop, Const))
2041 0 : {
2042 112 : Datum arraydatum = ((Const *) rightop)->constvalue;
2043 112 : bool arrayisnull = ((Const *) rightop)->constisnull;
2044 : ArrayType *arrayval;
2045 : int nitems;
2046 :
2047 112 : if (arrayisnull)
2048 0 : return false;
2049 112 : arrayval = DatumGetArrayTypeP(arraydatum);
2050 112 : nitems = ArrayGetNItems(ARR_NDIM(arrayval), ARR_DIMS(arrayval));
2051 112 : if (nitems > 0)
2052 112 : return true;
2053 : }
2054 0 : else if (rightop && IsA(rightop, ArrayExpr))
2055 : {
2056 0 : ArrayExpr *arrayexpr = (ArrayExpr *) rightop;
2057 :
2058 0 : if (arrayexpr->elements != NIL && !arrayexpr->multidims)
2059 0 : return true;
2060 : }
2061 0 : return false;
2062 : }
2063 :
2064 :
2065 : /*****************************************************************************
2066 : * Check for "pseudo-constant" clauses
2067 : *****************************************************************************/
2068 :
2069 : /*
2070 : * is_pseudo_constant_clause
2071 : * Detect whether an expression is "pseudo constant", ie, it contains no
2072 : * variables of the current query level and no uses of volatile functions.
2073 : * Such an expr is not necessarily a true constant: it can still contain
2074 : * Params and outer-level Vars, not to mention functions whose results
2075 : * may vary from one statement to the next. However, the expr's value
2076 : * will be constant over any one scan of the current query, so it can be
2077 : * used as, eg, an indexscan key. (Actually, the condition for indexscan
2078 : * keys is weaker than this; see is_pseudo_constant_for_index().)
2079 : *
2080 : * CAUTION: this function omits to test for one very important class of
2081 : * not-constant expressions, namely aggregates (Aggrefs). In current usage
2082 : * this is only applied to WHERE clauses and so a check for Aggrefs would be
2083 : * a waste of cycles; but be sure to also check contain_agg_clause() if you
2084 : * want to know about pseudo-constness in other contexts. The same goes
2085 : * for window functions (WindowFuncs).
2086 : */
2087 : bool
2088 4794 : is_pseudo_constant_clause(Node *clause)
2089 : {
2090 : /*
2091 : * We could implement this check in one recursive scan. But since the
2092 : * check for volatile functions is both moderately expensive and unlikely
2093 : * to fail, it seems better to look for Vars first and only check for
2094 : * volatile functions if we find no Vars.
2095 : */
2096 4794 : if (!contain_var_clause(clause) &&
2097 4794 : !contain_volatile_functions(clause))
2098 4794 : return true;
2099 0 : return false;
2100 : }
2101 :
2102 : /*
2103 : * is_pseudo_constant_clause_relids
2104 : * Same as above, except caller already has available the var membership
2105 : * of the expression; this lets us avoid the contain_var_clause() scan.
2106 : */
2107 : bool
2108 405500 : is_pseudo_constant_clause_relids(Node *clause, Relids relids)
2109 : {
2110 405500 : if (bms_is_empty(relids) &&
2111 398446 : !contain_volatile_functions(clause))
2112 398446 : return true;
2113 7054 : return false;
2114 : }
2115 :
2116 :
2117 : /*****************************************************************************
2118 : * *
2119 : * General clause-manipulating routines *
2120 : * *
2121 : *****************************************************************************/
2122 :
2123 : /*
2124 : * NumRelids
2125 : * (formerly clause_relids)
2126 : *
2127 : * Returns the number of different base relations referenced in 'clause'.
2128 : */
2129 : int
2130 1758 : NumRelids(PlannerInfo *root, Node *clause)
2131 : {
2132 : int result;
2133 1758 : Relids varnos = pull_varnos(root, clause);
2134 :
2135 1758 : varnos = bms_del_members(varnos, root->outer_join_rels);
2136 1758 : result = bms_num_members(varnos);
2137 1758 : bms_free(varnos);
2138 1758 : return result;
2139 : }
2140 :
2141 : /*
2142 : * CommuteOpExpr: commute a binary operator clause
2143 : *
2144 : * XXX the clause is destructively modified!
2145 : */
2146 : void
2147 16482 : CommuteOpExpr(OpExpr *clause)
2148 : {
2149 : Oid opoid;
2150 : Node *temp;
2151 :
2152 : /* Sanity checks: caller is at fault if these fail */
2153 32964 : if (!is_opclause(clause) ||
2154 16482 : list_length(clause->args) != 2)
2155 0 : elog(ERROR, "cannot commute non-binary-operator clause");
2156 :
2157 16482 : opoid = get_commutator(clause->opno);
2158 :
2159 16482 : if (!OidIsValid(opoid))
2160 0 : elog(ERROR, "could not find commutator for operator %u",
2161 : clause->opno);
2162 :
2163 : /*
2164 : * modify the clause in-place!
2165 : */
2166 16482 : clause->opno = opoid;
2167 16482 : clause->opfuncid = InvalidOid;
2168 : /* opresulttype, opretset, opcollid, inputcollid need not change */
2169 :
2170 16482 : temp = linitial(clause->args);
2171 16482 : linitial(clause->args) = lsecond(clause->args);
2172 16482 : lsecond(clause->args) = temp;
2173 16482 : }
2174 :
2175 : /*
2176 : * Helper for eval_const_expressions: check that datatype of an attribute
2177 : * is still what it was when the expression was parsed. This is needed to
2178 : * guard against improper simplification after ALTER COLUMN TYPE. (XXX we
2179 : * may well need to make similar checks elsewhere?)
2180 : *
2181 : * rowtypeid may come from a whole-row Var, and therefore it can be a domain
2182 : * over composite, but for this purpose we only care about checking the type
2183 : * of a contained field.
2184 : */
2185 : static bool
2186 526 : rowtype_field_matches(Oid rowtypeid, int fieldnum,
2187 : Oid expectedtype, int32 expectedtypmod,
2188 : Oid expectedcollation)
2189 : {
2190 : TupleDesc tupdesc;
2191 : Form_pg_attribute attr;
2192 :
2193 : /* No issue for RECORD, since there is no way to ALTER such a type */
2194 526 : if (rowtypeid == RECORDOID)
2195 42 : return true;
2196 484 : tupdesc = lookup_rowtype_tupdesc_domain(rowtypeid, -1, false);
2197 484 : if (fieldnum <= 0 || fieldnum > tupdesc->natts)
2198 : {
2199 0 : ReleaseTupleDesc(tupdesc);
2200 0 : return false;
2201 : }
2202 484 : attr = TupleDescAttr(tupdesc, fieldnum - 1);
2203 484 : if (attr->attisdropped ||
2204 484 : attr->atttypid != expectedtype ||
2205 484 : attr->atttypmod != expectedtypmod ||
2206 484 : attr->attcollation != expectedcollation)
2207 : {
2208 0 : ReleaseTupleDesc(tupdesc);
2209 0 : return false;
2210 : }
2211 484 : ReleaseTupleDesc(tupdesc);
2212 484 : return true;
2213 : }
2214 :
2215 :
2216 : /*--------------------
2217 : * eval_const_expressions
2218 : *
2219 : * Reduce any recognizably constant subexpressions of the given
2220 : * expression tree, for example "2 + 2" => "4". More interestingly,
2221 : * we can reduce certain boolean expressions even when they contain
2222 : * non-constant subexpressions: "x OR true" => "true" no matter what
2223 : * the subexpression x is. (XXX We assume that no such subexpression
2224 : * will have important side-effects, which is not necessarily a good
2225 : * assumption in the presence of user-defined functions; do we need a
2226 : * pg_proc flag that prevents discarding the execution of a function?)
2227 : *
2228 : * We do understand that certain functions may deliver non-constant
2229 : * results even with constant inputs, "nextval()" being the classic
2230 : * example. Functions that are not marked "immutable" in pg_proc
2231 : * will not be pre-evaluated here, although we will reduce their
2232 : * arguments as far as possible.
2233 : *
2234 : * Whenever a function is eliminated from the expression by means of
2235 : * constant-expression evaluation or inlining, we add the function to
2236 : * root->glob->invalItems. This ensures the plan is known to depend on
2237 : * such functions, even though they aren't referenced anymore.
2238 : *
2239 : * We assume that the tree has already been type-checked and contains
2240 : * only operators and functions that are reasonable to try to execute.
2241 : *
2242 : * NOTE: "root" can be passed as NULL if the caller never wants to do any
2243 : * Param substitutions nor receive info about inlined functions.
2244 : *
2245 : * NOTE: the planner assumes that this will always flatten nested AND and
2246 : * OR clauses into N-argument form. See comments in prepqual.c.
2247 : *
2248 : * NOTE: another critical effect is that any function calls that require
2249 : * default arguments will be expanded, and named-argument calls will be
2250 : * converted to positional notation. The executor won't handle either.
2251 : *--------------------
2252 : */
2253 : Node *
2254 1143290 : eval_const_expressions(PlannerInfo *root, Node *node)
2255 : {
2256 : eval_const_expressions_context context;
2257 :
2258 1143290 : if (root)
2259 900596 : context.boundParams = root->glob->boundParams; /* bound Params */
2260 : else
2261 242694 : context.boundParams = NULL;
2262 1143290 : context.root = root; /* for inlined-function dependencies */
2263 1143290 : context.active_fns = NIL; /* nothing being recursively simplified */
2264 1143290 : context.case_val = NULL; /* no CASE being examined */
2265 1143290 : context.estimate = false; /* safe transformations only */
2266 1143290 : return eval_const_expressions_mutator(node, &context);
2267 : }
2268 :
2269 : #define MIN_ARRAY_SIZE_FOR_HASHED_SAOP 9
2270 : /*--------------------
2271 : * convert_saop_to_hashed_saop
2272 : *
2273 : * Recursively search 'node' for ScalarArrayOpExprs and fill in the hash
2274 : * function for any ScalarArrayOpExpr that looks like it would be useful to
2275 : * evaluate using a hash table rather than a linear search.
2276 : *
2277 : * We'll use a hash table if all of the following conditions are met:
2278 : * 1. The 2nd argument of the array contain only Consts.
2279 : * 2. useOr is true or there is a valid negator operator for the
2280 : * ScalarArrayOpExpr's opno.
2281 : * 3. There's valid hash function for both left and righthand operands and
2282 : * these hash functions are the same.
2283 : * 4. If the array contains enough elements for us to consider it to be
2284 : * worthwhile using a hash table rather than a linear search.
2285 : */
2286 : void
2287 789978 : convert_saop_to_hashed_saop(Node *node)
2288 : {
2289 789978 : (void) convert_saop_to_hashed_saop_walker(node, NULL);
2290 789978 : }
2291 :
2292 : static bool
2293 5684306 : convert_saop_to_hashed_saop_walker(Node *node, void *context)
2294 : {
2295 5684306 : if (node == NULL)
2296 144394 : return false;
2297 :
2298 5539912 : if (IsA(node, ScalarArrayOpExpr))
2299 : {
2300 29248 : ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) node;
2301 29248 : Expr *arrayarg = (Expr *) lsecond(saop->args);
2302 : Oid lefthashfunc;
2303 : Oid righthashfunc;
2304 :
2305 29248 : if (arrayarg && IsA(arrayarg, Const) &&
2306 15646 : !((Const *) arrayarg)->constisnull)
2307 : {
2308 15628 : if (saop->useOr)
2309 : {
2310 11368 : if (get_op_hash_functions(saop->opno, &lefthashfunc, &righthashfunc) &&
2311 11080 : lefthashfunc == righthashfunc)
2312 : {
2313 11080 : Datum arrdatum = ((Const *) arrayarg)->constvalue;
2314 11080 : ArrayType *arr = (ArrayType *) DatumGetPointer(arrdatum);
2315 : int nitems;
2316 :
2317 : /*
2318 : * Only fill in the hash functions if the array looks
2319 : * large enough for it to be worth hashing instead of
2320 : * doing a linear search.
2321 : */
2322 11080 : nitems = ArrayGetNItems(ARR_NDIM(arr), ARR_DIMS(arr));
2323 :
2324 11080 : if (nitems >= MIN_ARRAY_SIZE_FOR_HASHED_SAOP)
2325 : {
2326 : /* Looks good. Fill in the hash functions */
2327 196 : saop->hashfuncid = lefthashfunc;
2328 : }
2329 15242 : return true;
2330 : }
2331 : }
2332 : else /* !saop->useOr */
2333 : {
2334 4260 : Oid negator = get_negator(saop->opno);
2335 :
2336 : /*
2337 : * Check if this is a NOT IN using an operator whose negator
2338 : * is hashable. If so we can still build a hash table and
2339 : * just ensure the lookup items are not in the hash table.
2340 : */
2341 8520 : if (OidIsValid(negator) &&
2342 4260 : get_op_hash_functions(negator, &lefthashfunc, &righthashfunc) &&
2343 4162 : lefthashfunc == righthashfunc)
2344 : {
2345 4162 : Datum arrdatum = ((Const *) arrayarg)->constvalue;
2346 4162 : ArrayType *arr = (ArrayType *) DatumGetPointer(arrdatum);
2347 : int nitems;
2348 :
2349 : /*
2350 : * Only fill in the hash functions if the array looks
2351 : * large enough for it to be worth hashing instead of
2352 : * doing a linear search.
2353 : */
2354 4162 : nitems = ArrayGetNItems(ARR_NDIM(arr), ARR_DIMS(arr));
2355 :
2356 4162 : if (nitems >= MIN_ARRAY_SIZE_FOR_HASHED_SAOP)
2357 : {
2358 : /* Looks good. Fill in the hash functions */
2359 70 : saop->hashfuncid = lefthashfunc;
2360 :
2361 : /*
2362 : * Also set the negfuncid. The executor will need
2363 : * that to perform hashtable lookups.
2364 : */
2365 70 : saop->negfuncid = get_opcode(negator);
2366 : }
2367 4162 : return true;
2368 : }
2369 : }
2370 : }
2371 : }
2372 :
2373 5524670 : return expression_tree_walker(node, convert_saop_to_hashed_saop_walker, NULL);
2374 : }
2375 :
2376 :
2377 : /*--------------------
2378 : * estimate_expression_value
2379 : *
2380 : * This function attempts to estimate the value of an expression for
2381 : * planning purposes. It is in essence a more aggressive version of
2382 : * eval_const_expressions(): we will perform constant reductions that are
2383 : * not necessarily 100% safe, but are reasonable for estimation purposes.
2384 : *
2385 : * Currently the extra steps that are taken in this mode are:
2386 : * 1. Substitute values for Params, where a bound Param value has been made
2387 : * available by the caller of planner(), even if the Param isn't marked
2388 : * constant. This effectively means that we plan using the first supplied
2389 : * value of the Param.
2390 : * 2. Fold stable, as well as immutable, functions to constants.
2391 : * 3. Reduce PlaceHolderVar nodes to their contained expressions.
2392 : *--------------------
2393 : */
2394 : Node *
2395 739042 : estimate_expression_value(PlannerInfo *root, Node *node)
2396 : {
2397 : eval_const_expressions_context context;
2398 :
2399 739042 : context.boundParams = root->glob->boundParams; /* bound Params */
2400 : /* we do not need to mark the plan as depending on inlined functions */
2401 739042 : context.root = NULL;
2402 739042 : context.active_fns = NIL; /* nothing being recursively simplified */
2403 739042 : context.case_val = NULL; /* no CASE being examined */
2404 739042 : context.estimate = true; /* unsafe transformations OK */
2405 739042 : return eval_const_expressions_mutator(node, &context);
2406 : }
2407 :
2408 : /*
2409 : * The generic case in eval_const_expressions_mutator is to recurse using
2410 : * expression_tree_mutator, which will copy the given node unchanged but
2411 : * const-simplify its arguments (if any) as far as possible. If the node
2412 : * itself does immutable processing, and each of its arguments were reduced
2413 : * to a Const, we can then reduce it to a Const using evaluate_expr. (Some
2414 : * node types need more complicated logic; for example, a CASE expression
2415 : * might be reducible to a constant even if not all its subtrees are.)
2416 : */
2417 : #define ece_generic_processing(node) \
2418 : expression_tree_mutator((Node *) (node), eval_const_expressions_mutator, \
2419 : (void *) context)
2420 :
2421 : /*
2422 : * Check whether all arguments of the given node were reduced to Consts.
2423 : * By going directly to expression_tree_walker, contain_non_const_walker
2424 : * is not applied to the node itself, only to its children.
2425 : */
2426 : #define ece_all_arguments_const(node) \
2427 : (!expression_tree_walker((Node *) (node), contain_non_const_walker, NULL))
2428 :
2429 : /* Generic macro for applying evaluate_expr */
2430 : #define ece_evaluate_expr(node) \
2431 : ((Node *) evaluate_expr((Expr *) (node), \
2432 : exprType((Node *) (node)), \
2433 : exprTypmod((Node *) (node)), \
2434 : exprCollation((Node *) (node))))
2435 :
2436 : /*
2437 : * Recursive guts of eval_const_expressions/estimate_expression_value
2438 : */
2439 : static Node *
2440 8351052 : eval_const_expressions_mutator(Node *node,
2441 : eval_const_expressions_context *context)
2442 : {
2443 :
2444 : /* since this function recurses, it could be driven to stack overflow */
2445 8351052 : check_stack_depth();
2446 :
2447 8351052 : if (node == NULL)
2448 376142 : return NULL;
2449 7974910 : switch (nodeTag(node))
2450 : {
2451 265842 : case T_Param:
2452 : {
2453 265842 : Param *param = (Param *) node;
2454 265842 : ParamListInfo paramLI = context->boundParams;
2455 :
2456 : /* Look to see if we've been given a value for this Param */
2457 265842 : if (param->paramkind == PARAM_EXTERN &&
2458 38190 : paramLI != NULL &&
2459 38190 : param->paramid > 0 &&
2460 38190 : param->paramid <= paramLI->numParams)
2461 : {
2462 : ParamExternData *prm;
2463 : ParamExternData prmdata;
2464 :
2465 : /*
2466 : * Give hook a chance in case parameter is dynamic. Tell
2467 : * it that this fetch is speculative, so it should avoid
2468 : * erroring out if parameter is unavailable.
2469 : */
2470 38190 : if (paramLI->paramFetch != NULL)
2471 7152 : prm = paramLI->paramFetch(paramLI, param->paramid,
2472 : true, &prmdata);
2473 : else
2474 31038 : prm = ¶mLI->params[param->paramid - 1];
2475 :
2476 : /*
2477 : * We don't just check OidIsValid, but insist that the
2478 : * fetched type match the Param, just in case the hook did
2479 : * something unexpected. No need to throw an error here
2480 : * though; leave that for runtime.
2481 : */
2482 38190 : if (OidIsValid(prm->ptype) &&
2483 38190 : prm->ptype == param->paramtype)
2484 : {
2485 : /* OK to substitute parameter value? */
2486 38188 : if (context->estimate ||
2487 38182 : (prm->pflags & PARAM_FLAG_CONST))
2488 : {
2489 : /*
2490 : * Return a Const representing the param value.
2491 : * Must copy pass-by-ref datatypes, since the
2492 : * Param might be in a memory context
2493 : * shorter-lived than our output plan should be.
2494 : */
2495 : int16 typLen;
2496 : bool typByVal;
2497 : Datum pval;
2498 : Const *con;
2499 :
2500 38182 : get_typlenbyval(param->paramtype,
2501 : &typLen, &typByVal);
2502 38182 : if (prm->isnull || typByVal)
2503 24708 : pval = prm->value;
2504 : else
2505 13474 : pval = datumCopy(prm->value, typByVal, typLen);
2506 38182 : con = makeConst(param->paramtype,
2507 : param->paramtypmod,
2508 : param->paramcollid,
2509 : (int) typLen,
2510 : pval,
2511 38182 : prm->isnull,
2512 : typByVal);
2513 38182 : con->location = param->location;
2514 38182 : return (Node *) con;
2515 : }
2516 : }
2517 : }
2518 :
2519 : /*
2520 : * Not replaceable, so just copy the Param (no need to
2521 : * recurse)
2522 : */
2523 227660 : return (Node *) copyObject(param);
2524 : }
2525 3158 : case T_WindowFunc:
2526 : {
2527 3158 : WindowFunc *expr = (WindowFunc *) node;
2528 3158 : Oid funcid = expr->winfnoid;
2529 : List *args;
2530 : Expr *aggfilter;
2531 : HeapTuple func_tuple;
2532 : WindowFunc *newexpr;
2533 :
2534 : /*
2535 : * We can't really simplify a WindowFunc node, but we mustn't
2536 : * just fall through to the default processing, because we
2537 : * have to apply expand_function_arguments to its argument
2538 : * list. That takes care of inserting default arguments and
2539 : * expanding named-argument notation.
2540 : */
2541 3158 : func_tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
2542 3158 : if (!HeapTupleIsValid(func_tuple))
2543 0 : elog(ERROR, "cache lookup failed for function %u", funcid);
2544 :
2545 3158 : args = expand_function_arguments(expr->args,
2546 : false, expr->wintype,
2547 : func_tuple);
2548 :
2549 3158 : ReleaseSysCache(func_tuple);
2550 :
2551 : /* Now, recursively simplify the args (which are a List) */
2552 : args = (List *)
2553 3158 : expression_tree_mutator((Node *) args,
2554 : eval_const_expressions_mutator,
2555 : (void *) context);
2556 : /* ... and the filter expression, which isn't */
2557 : aggfilter = (Expr *)
2558 3158 : eval_const_expressions_mutator((Node *) expr->aggfilter,
2559 : context);
2560 :
2561 : /* And build the replacement WindowFunc node */
2562 3158 : newexpr = makeNode(WindowFunc);
2563 3158 : newexpr->winfnoid = expr->winfnoid;
2564 3158 : newexpr->wintype = expr->wintype;
2565 3158 : newexpr->wincollid = expr->wincollid;
2566 3158 : newexpr->inputcollid = expr->inputcollid;
2567 3158 : newexpr->args = args;
2568 3158 : newexpr->aggfilter = aggfilter;
2569 3158 : newexpr->runCondition = expr->runCondition;
2570 3158 : newexpr->winref = expr->winref;
2571 3158 : newexpr->winstar = expr->winstar;
2572 3158 : newexpr->winagg = expr->winagg;
2573 3158 : newexpr->location = expr->location;
2574 :
2575 3158 : return (Node *) newexpr;
2576 : }
2577 531818 : case T_FuncExpr:
2578 : {
2579 531818 : FuncExpr *expr = (FuncExpr *) node;
2580 531818 : List *args = expr->args;
2581 : Expr *simple;
2582 : FuncExpr *newexpr;
2583 :
2584 : /*
2585 : * Code for op/func reduction is pretty bulky, so split it out
2586 : * as a separate function. Note: exprTypmod normally returns
2587 : * -1 for a FuncExpr, but not when the node is recognizably a
2588 : * length coercion; we want to preserve the typmod in the
2589 : * eventual Const if so.
2590 : */
2591 531818 : simple = simplify_function(expr->funcid,
2592 : expr->funcresulttype,
2593 : exprTypmod(node),
2594 : expr->funccollid,
2595 : expr->inputcollid,
2596 : &args,
2597 531818 : expr->funcvariadic,
2598 : true,
2599 : true,
2600 : context);
2601 529322 : if (simple) /* successfully simplified it */
2602 169504 : return (Node *) simple;
2603 :
2604 : /*
2605 : * The expression cannot be simplified any further, so build
2606 : * and return a replacement FuncExpr node using the
2607 : * possibly-simplified arguments. Note that we have also
2608 : * converted the argument list to positional notation.
2609 : */
2610 359818 : newexpr = makeNode(FuncExpr);
2611 359818 : newexpr->funcid = expr->funcid;
2612 359818 : newexpr->funcresulttype = expr->funcresulttype;
2613 359818 : newexpr->funcretset = expr->funcretset;
2614 359818 : newexpr->funcvariadic = expr->funcvariadic;
2615 359818 : newexpr->funcformat = expr->funcformat;
2616 359818 : newexpr->funccollid = expr->funccollid;
2617 359818 : newexpr->inputcollid = expr->inputcollid;
2618 359818 : newexpr->args = args;
2619 359818 : newexpr->location = expr->location;
2620 359818 : return (Node *) newexpr;
2621 : }
2622 662030 : case T_OpExpr:
2623 : {
2624 662030 : OpExpr *expr = (OpExpr *) node;
2625 662030 : List *args = expr->args;
2626 : Expr *simple;
2627 : OpExpr *newexpr;
2628 :
2629 : /*
2630 : * Need to get OID of underlying function. Okay to scribble
2631 : * on input to this extent.
2632 : */
2633 662030 : set_opfuncid(expr);
2634 :
2635 : /*
2636 : * Code for op/func reduction is pretty bulky, so split it out
2637 : * as a separate function.
2638 : */
2639 662030 : simple = simplify_function(expr->opfuncid,
2640 : expr->opresulttype, -1,
2641 : expr->opcollid,
2642 : expr->inputcollid,
2643 : &args,
2644 : false,
2645 : true,
2646 : true,
2647 : context);
2648 660872 : if (simple) /* successfully simplified it */
2649 18466 : return (Node *) simple;
2650 :
2651 : /*
2652 : * If the operator is boolean equality or inequality, we know
2653 : * how to simplify cases involving one constant and one
2654 : * non-constant argument.
2655 : */
2656 642406 : if (expr->opno == BooleanEqualOperator ||
2657 641636 : expr->opno == BooleanNotEqualOperator)
2658 : {
2659 932 : simple = (Expr *) simplify_boolean_equality(expr->opno,
2660 : args);
2661 932 : if (simple) /* successfully simplified it */
2662 754 : return (Node *) simple;
2663 : }
2664 :
2665 : /*
2666 : * The expression cannot be simplified any further, so build
2667 : * and return a replacement OpExpr node using the
2668 : * possibly-simplified arguments.
2669 : */
2670 641652 : newexpr = makeNode(OpExpr);
2671 641652 : newexpr->opno = expr->opno;
2672 641652 : newexpr->opfuncid = expr->opfuncid;
2673 641652 : newexpr->opresulttype = expr->opresulttype;
2674 641652 : newexpr->opretset = expr->opretset;
2675 641652 : newexpr->opcollid = expr->opcollid;
2676 641652 : newexpr->inputcollid = expr->inputcollid;
2677 641652 : newexpr->args = args;
2678 641652 : newexpr->location = expr->location;
2679 641652 : return (Node *) newexpr;
2680 : }
2681 880 : case T_DistinctExpr:
2682 : {
2683 880 : DistinctExpr *expr = (DistinctExpr *) node;
2684 : List *args;
2685 : ListCell *arg;
2686 880 : bool has_null_input = false;
2687 880 : bool all_null_input = true;
2688 880 : bool has_nonconst_input = false;
2689 : Expr *simple;
2690 : DistinctExpr *newexpr;
2691 :
2692 : /*
2693 : * Reduce constants in the DistinctExpr's arguments. We know
2694 : * args is either NIL or a List node, so we can call
2695 : * expression_tree_mutator directly rather than recursing to
2696 : * self.
2697 : */
2698 880 : args = (List *) expression_tree_mutator((Node *) expr->args,
2699 : eval_const_expressions_mutator,
2700 : (void *) context);
2701 :
2702 : /*
2703 : * We must do our own check for NULLs because DistinctExpr has
2704 : * different results for NULL input than the underlying
2705 : * operator does.
2706 : */
2707 2640 : foreach(arg, args)
2708 : {
2709 1760 : if (IsA(lfirst(arg), Const))
2710 : {
2711 90 : has_null_input |= ((Const *) lfirst(arg))->constisnull;
2712 90 : all_null_input &= ((Const *) lfirst(arg))->constisnull;
2713 : }
2714 : else
2715 1670 : has_nonconst_input = true;
2716 : }
2717 :
2718 : /* all constants? then can optimize this out */
2719 880 : if (!has_nonconst_input)
2720 : {
2721 : /* all nulls? then not distinct */
2722 24 : if (all_null_input)
2723 0 : return makeBoolConst(false, false);
2724 :
2725 : /* one null? then distinct */
2726 24 : if (has_null_input)
2727 0 : return makeBoolConst(true, false);
2728 :
2729 : /* otherwise try to evaluate the '=' operator */
2730 : /* (NOT okay to try to inline it, though!) */
2731 :
2732 : /*
2733 : * Need to get OID of underlying function. Okay to
2734 : * scribble on input to this extent.
2735 : */
2736 24 : set_opfuncid((OpExpr *) expr); /* rely on struct
2737 : * equivalence */
2738 :
2739 : /*
2740 : * Code for op/func reduction is pretty bulky, so split it
2741 : * out as a separate function.
2742 : */
2743 24 : simple = simplify_function(expr->opfuncid,
2744 : expr->opresulttype, -1,
2745 : expr->opcollid,
2746 : expr->inputcollid,
2747 : &args,
2748 : false,
2749 : false,
2750 : false,
2751 : context);
2752 24 : if (simple) /* successfully simplified it */
2753 : {
2754 : /*
2755 : * Since the underlying operator is "=", must negate
2756 : * its result
2757 : */
2758 24 : Const *csimple = castNode(Const, simple);
2759 :
2760 24 : csimple->constvalue =
2761 24 : BoolGetDatum(!DatumGetBool(csimple->constvalue));
2762 24 : return (Node *) csimple;
2763 : }
2764 : }
2765 :
2766 : /*
2767 : * The expression cannot be simplified any further, so build
2768 : * and return a replacement DistinctExpr node using the
2769 : * possibly-simplified arguments.
2770 : */
2771 856 : newexpr = makeNode(DistinctExpr);
2772 856 : newexpr->opno = expr->opno;
2773 856 : newexpr->opfuncid = expr->opfuncid;
2774 856 : newexpr->opresulttype = expr->opresulttype;
2775 856 : newexpr->opretset = expr->opretset;
2776 856 : newexpr->opcollid = expr->opcollid;
2777 856 : newexpr->inputcollid = expr->inputcollid;
2778 856 : newexpr->args = args;
2779 856 : newexpr->location = expr->location;
2780 856 : return (Node *) newexpr;
2781 : }
2782 190 : case T_NullIfExpr:
2783 : {
2784 : NullIfExpr *expr;
2785 : ListCell *arg;
2786 190 : bool has_nonconst_input = false;
2787 :
2788 : /* Copy the node and const-simplify its arguments */
2789 190 : expr = (NullIfExpr *) ece_generic_processing(node);
2790 :
2791 : /* If either argument is NULL they can't be equal */
2792 564 : foreach(arg, expr->args)
2793 : {
2794 380 : if (!IsA(lfirst(arg), Const))
2795 158 : has_nonconst_input = true;
2796 222 : else if (((Const *) lfirst(arg))->constisnull)
2797 6 : return (Node *) linitial(expr->args);
2798 : }
2799 :
2800 : /*
2801 : * Need to get OID of underlying function before checking if
2802 : * the function is OK to evaluate.
2803 : */
2804 184 : set_opfuncid((OpExpr *) expr);
2805 :
2806 222 : if (!has_nonconst_input &&
2807 38 : ece_function_is_safe(expr->opfuncid, context))
2808 38 : return ece_evaluate_expr(expr);
2809 :
2810 146 : return (Node *) expr;
2811 : }
2812 35588 : case T_ScalarArrayOpExpr:
2813 : {
2814 : ScalarArrayOpExpr *saop;
2815 :
2816 : /* Copy the node and const-simplify its arguments */
2817 35588 : saop = (ScalarArrayOpExpr *) ece_generic_processing(node);
2818 :
2819 : /* Make sure we know underlying function */
2820 35588 : set_sa_opfuncid(saop);
2821 :
2822 : /*
2823 : * If all arguments are Consts, and it's a safe function, we
2824 : * can fold to a constant
2825 : */
2826 35780 : if (ece_all_arguments_const(saop) &&
2827 192 : ece_function_is_safe(saop->opfuncid, context))
2828 192 : return ece_evaluate_expr(saop);
2829 35396 : return (Node *) saop;
2830 : }
2831 156294 : case T_BoolExpr:
2832 : {
2833 156294 : BoolExpr *expr = (BoolExpr *) node;
2834 :
2835 156294 : switch (expr->boolop)
2836 : {
2837 13986 : case OR_EXPR:
2838 : {
2839 : List *newargs;
2840 13986 : bool haveNull = false;
2841 13986 : bool forceTrue = false;
2842 :
2843 13986 : newargs = simplify_or_arguments(expr->args,
2844 : context,
2845 : &haveNull,
2846 : &forceTrue);
2847 13986 : if (forceTrue)
2848 148 : return makeBoolConst(true, false);
2849 13838 : if (haveNull)
2850 30 : newargs = lappend(newargs,
2851 30 : makeBoolConst(false, true));
2852 : /* If all the inputs are FALSE, result is FALSE */
2853 13838 : if (newargs == NIL)
2854 6 : return makeBoolConst(false, false);
2855 :
2856 : /*
2857 : * If only one nonconst-or-NULL input, it's the
2858 : * result
2859 : */
2860 13832 : if (list_length(newargs) == 1)
2861 96 : return (Node *) linitial(newargs);
2862 : /* Else we still need an OR node */
2863 13736 : return (Node *) make_orclause(newargs);
2864 : }
2865 130108 : case AND_EXPR:
2866 : {
2867 : List *newargs;
2868 130108 : bool haveNull = false;
2869 130108 : bool forceFalse = false;
2870 :
2871 130108 : newargs = simplify_and_arguments(expr->args,
2872 : context,
2873 : &haveNull,
2874 : &forceFalse);
2875 130108 : if (forceFalse)
2876 1466 : return makeBoolConst(false, false);
2877 128642 : if (haveNull)
2878 6 : newargs = lappend(newargs,
2879 6 : makeBoolConst(false, true));
2880 : /* If all the inputs are TRUE, result is TRUE */
2881 128642 : if (newargs == NIL)
2882 364 : return makeBoolConst(true, false);
2883 :
2884 : /*
2885 : * If only one nonconst-or-NULL input, it's the
2886 : * result
2887 : */
2888 128278 : if (list_length(newargs) == 1)
2889 26 : return (Node *) linitial(newargs);
2890 : /* Else we still need an AND node */
2891 128252 : return (Node *) make_andclause(newargs);
2892 : }
2893 12200 : case NOT_EXPR:
2894 : {
2895 : Node *arg;
2896 :
2897 : Assert(list_length(expr->args) == 1);
2898 12200 : arg = eval_const_expressions_mutator(linitial(expr->args),
2899 : context);
2900 :
2901 : /*
2902 : * Use negate_clause() to see if we can simplify
2903 : * away the NOT.
2904 : */
2905 12200 : return negate_clause(arg);
2906 : }
2907 0 : default:
2908 0 : elog(ERROR, "unrecognized boolop: %d",
2909 : (int) expr->boolop);
2910 : break;
2911 : }
2912 : break;
2913 : }
2914 :
2915 750 : case T_JsonValueExpr:
2916 : {
2917 750 : JsonValueExpr *jve = (JsonValueExpr *) node;
2918 750 : Node *raw_expr = (Node *) jve->raw_expr;
2919 750 : Node *formatted_expr = (Node *) jve->formatted_expr;
2920 :
2921 : /*
2922 : * If we can fold formatted_expr to a constant, we can elide
2923 : * the JsonValueExpr altogether. Otherwise we must process
2924 : * raw_expr too. But JsonFormat is a flat node and requires
2925 : * no simplification, only copying.
2926 : */
2927 750 : formatted_expr = eval_const_expressions_mutator(formatted_expr,
2928 : context);
2929 750 : if (formatted_expr && IsA(formatted_expr, Const))
2930 522 : return formatted_expr;
2931 :
2932 228 : raw_expr = eval_const_expressions_mutator(raw_expr, context);
2933 :
2934 228 : return (Node *) makeJsonValueExpr((Expr *) raw_expr,
2935 : (Expr *) formatted_expr,
2936 228 : copyObject(jve->format));
2937 : }
2938 :
2939 540 : case T_SubPlan:
2940 : case T_AlternativeSubPlan:
2941 :
2942 : /*
2943 : * Return a SubPlan unchanged --- too late to do anything with it.
2944 : *
2945 : * XXX should we ereport() here instead? Probably this routine
2946 : * should never be invoked after SubPlan creation.
2947 : */
2948 540 : return node;
2949 150182 : case T_RelabelType:
2950 : {
2951 150182 : RelabelType *relabel = (RelabelType *) node;
2952 : Node *arg;
2953 :
2954 : /* Simplify the input ... */
2955 150182 : arg = eval_const_expressions_mutator((Node *) relabel->arg,
2956 : context);
2957 : /* ... and attach a new RelabelType node, if needed */
2958 150182 : return applyRelabelType(arg,
2959 : relabel->resulttype,
2960 : relabel->resulttypmod,
2961 : relabel->resultcollid,
2962 : relabel->relabelformat,
2963 : relabel->location,
2964 : true);
2965 : }
2966 24020 : case T_CoerceViaIO:
2967 : {
2968 24020 : CoerceViaIO *expr = (CoerceViaIO *) node;
2969 : List *args;
2970 : Oid outfunc;
2971 : bool outtypisvarlena;
2972 : Oid infunc;
2973 : Oid intypioparam;
2974 : Expr *simple;
2975 : CoerceViaIO *newexpr;
2976 :
2977 : /* Make a List so we can use simplify_function */
2978 24020 : args = list_make1(expr->arg);
2979 :
2980 : /*
2981 : * CoerceViaIO represents calling the source type's output
2982 : * function then the result type's input function. So, try to
2983 : * simplify it as though it were a stack of two such function
2984 : * calls. First we need to know what the functions are.
2985 : *
2986 : * Note that the coercion functions are assumed not to care
2987 : * about input collation, so we just pass InvalidOid for that.
2988 : */
2989 24020 : getTypeOutputInfo(exprType((Node *) expr->arg),
2990 : &outfunc, &outtypisvarlena);
2991 24020 : getTypeInputInfo(expr->resulttype,
2992 : &infunc, &intypioparam);
2993 :
2994 24020 : simple = simplify_function(outfunc,
2995 : CSTRINGOID, -1,
2996 : InvalidOid,
2997 : InvalidOid,
2998 : &args,
2999 : false,
3000 : true,
3001 : true,
3002 : context);
3003 24020 : if (simple) /* successfully simplified output fn */
3004 : {
3005 : /*
3006 : * Input functions may want 1 to 3 arguments. We always
3007 : * supply all three, trusting that nothing downstream will
3008 : * complain.
3009 : */
3010 2064 : args = list_make3(simple,
3011 : makeConst(OIDOID,
3012 : -1,
3013 : InvalidOid,
3014 : sizeof(Oid),
3015 : ObjectIdGetDatum(intypioparam),
3016 : false,
3017 : true),
3018 : makeConst(INT4OID,
3019 : -1,
3020 : InvalidOid,
3021 : sizeof(int32),
3022 : Int32GetDatum(-1),
3023 : false,
3024 : true));
3025 :
3026 2064 : simple = simplify_function(infunc,
3027 : expr->resulttype, -1,
3028 : expr->resultcollid,
3029 : InvalidOid,
3030 : &args,
3031 : false,
3032 : false,
3033 : true,
3034 : context);
3035 2012 : if (simple) /* successfully simplified input fn */
3036 1962 : return (Node *) simple;
3037 : }
3038 :
3039 : /*
3040 : * The expression cannot be simplified any further, so build
3041 : * and return a replacement CoerceViaIO node using the
3042 : * possibly-simplified argument.
3043 : */
3044 22006 : newexpr = makeNode(CoerceViaIO);
3045 22006 : newexpr->arg = (Expr *) linitial(args);
3046 22006 : newexpr->resulttype = expr->resulttype;
3047 22006 : newexpr->resultcollid = expr->resultcollid;
3048 22006 : newexpr->coerceformat = expr->coerceformat;
3049 22006 : newexpr->location = expr->location;
3050 22006 : return (Node *) newexpr;
3051 : }
3052 9104 : case T_ArrayCoerceExpr:
3053 : {
3054 9104 : ArrayCoerceExpr *ac = makeNode(ArrayCoerceExpr);
3055 : Node *save_case_val;
3056 :
3057 : /*
3058 : * Copy the node and const-simplify its arguments. We can't
3059 : * use ece_generic_processing() here because we need to mess
3060 : * with case_val only while processing the elemexpr.
3061 : */
3062 9104 : memcpy(ac, node, sizeof(ArrayCoerceExpr));
3063 9104 : ac->arg = (Expr *)
3064 9104 : eval_const_expressions_mutator((Node *) ac->arg,
3065 : context);
3066 :
3067 : /*
3068 : * Set up for the CaseTestExpr node contained in the elemexpr.
3069 : * We must prevent it from absorbing any outer CASE value.
3070 : */
3071 9104 : save_case_val = context->case_val;
3072 9104 : context->case_val = NULL;
3073 :
3074 9104 : ac->elemexpr = (Expr *)
3075 9104 : eval_const_expressions_mutator((Node *) ac->elemexpr,
3076 : context);
3077 :
3078 9104 : context->case_val = save_case_val;
3079 :
3080 : /*
3081 : * If constant argument and the per-element expression is
3082 : * immutable, we can simplify the whole thing to a constant.
3083 : * Exception: although contain_mutable_functions considers
3084 : * CoerceToDomain immutable for historical reasons, let's not
3085 : * do so here; this ensures coercion to an array-over-domain
3086 : * does not apply the domain's constraints until runtime.
3087 : */
3088 9104 : if (ac->arg && IsA(ac->arg, Const) &&
3089 986 : ac->elemexpr && !IsA(ac->elemexpr, CoerceToDomain) &&
3090 962 : !contain_mutable_functions((Node *) ac->elemexpr))
3091 962 : return ece_evaluate_expr(ac);
3092 :
3093 8142 : return (Node *) ac;
3094 : }
3095 8086 : case T_CollateExpr:
3096 : {
3097 : /*
3098 : * We replace CollateExpr with RelabelType, so as to improve
3099 : * uniformity of expression representation and thus simplify
3100 : * comparison of expressions. Hence this looks very nearly
3101 : * the same as the RelabelType case, and we can apply the same
3102 : * optimizations to avoid unnecessary RelabelTypes.
3103 : */
3104 8086 : CollateExpr *collate = (CollateExpr *) node;
3105 : Node *arg;
3106 :
3107 : /* Simplify the input ... */
3108 8086 : arg = eval_const_expressions_mutator((Node *) collate->arg,
3109 : context);
3110 : /* ... and attach a new RelabelType node, if needed */
3111 8086 : return applyRelabelType(arg,
3112 : exprType(arg),
3113 : exprTypmod(arg),
3114 : collate->collOid,
3115 : COERCE_IMPLICIT_CAST,
3116 : collate->location,
3117 : true);
3118 : }
3119 51312 : case T_CaseExpr:
3120 : {
3121 : /*----------
3122 : * CASE expressions can be simplified if there are constant
3123 : * condition clauses:
3124 : * FALSE (or NULL): drop the alternative
3125 : * TRUE: drop all remaining alternatives
3126 : * If the first non-FALSE alternative is a constant TRUE,
3127 : * we can simplify the entire CASE to that alternative's
3128 : * expression. If there are no non-FALSE alternatives,
3129 : * we simplify the entire CASE to the default result (ELSE).
3130 : *
3131 : * If we have a simple-form CASE with constant test
3132 : * expression, we substitute the constant value for contained
3133 : * CaseTestExpr placeholder nodes, so that we have the
3134 : * opportunity to reduce constant test conditions. For
3135 : * example this allows
3136 : * CASE 0 WHEN 0 THEN 1 ELSE 1/0 END
3137 : * to reduce to 1 rather than drawing a divide-by-0 error.
3138 : * Note that when the test expression is constant, we don't
3139 : * have to include it in the resulting CASE; for example
3140 : * CASE 0 WHEN x THEN y ELSE z END
3141 : * is transformed by the parser to
3142 : * CASE 0 WHEN CaseTestExpr = x THEN y ELSE z END
3143 : * which we can simplify to
3144 : * CASE WHEN 0 = x THEN y ELSE z END
3145 : * It is not necessary for the executor to evaluate the "arg"
3146 : * expression when executing the CASE, since any contained
3147 : * CaseTestExprs that might have referred to it will have been
3148 : * replaced by the constant.
3149 : *----------
3150 : */
3151 51312 : CaseExpr *caseexpr = (CaseExpr *) node;
3152 : CaseExpr *newcase;
3153 : Node *save_case_val;
3154 : Node *newarg;
3155 : List *newargs;
3156 : bool const_true_cond;
3157 51312 : Node *defresult = NULL;
3158 : ListCell *arg;
3159 :
3160 : /* Simplify the test expression, if any */
3161 51312 : newarg = eval_const_expressions_mutator((Node *) caseexpr->arg,
3162 : context);
3163 :
3164 : /* Set up for contained CaseTestExpr nodes */
3165 51312 : save_case_val = context->case_val;
3166 51312 : if (newarg && IsA(newarg, Const))
3167 : {
3168 18 : context->case_val = newarg;
3169 18 : newarg = NULL; /* not needed anymore, see above */
3170 : }
3171 : else
3172 51294 : context->case_val = NULL;
3173 :
3174 : /* Simplify the WHEN clauses */
3175 51312 : newargs = NIL;
3176 51312 : const_true_cond = false;
3177 144530 : foreach(arg, caseexpr->args)
3178 : {
3179 93544 : CaseWhen *oldcasewhen = lfirst_node(CaseWhen, arg);
3180 : Node *casecond;
3181 : Node *caseresult;
3182 :
3183 : /* Simplify this alternative's test condition */
3184 93544 : casecond = eval_const_expressions_mutator((Node *) oldcasewhen->expr,
3185 : context);
3186 :
3187 : /*
3188 : * If the test condition is constant FALSE (or NULL), then
3189 : * drop this WHEN clause completely, without processing
3190 : * the result.
3191 : */
3192 93544 : if (casecond && IsA(casecond, Const))
3193 : {
3194 986 : Const *const_input = (Const *) casecond;
3195 :
3196 986 : if (const_input->constisnull ||
3197 986 : !DatumGetBool(const_input->constvalue))
3198 666 : continue; /* drop alternative with FALSE cond */
3199 : /* Else it's constant TRUE */
3200 320 : const_true_cond = true;
3201 : }
3202 :
3203 : /* Simplify this alternative's result value */
3204 92878 : caseresult = eval_const_expressions_mutator((Node *) oldcasewhen->result,
3205 : context);
3206 :
3207 : /* If non-constant test condition, emit a new WHEN node */
3208 92872 : if (!const_true_cond)
3209 : {
3210 92552 : CaseWhen *newcasewhen = makeNode(CaseWhen);
3211 :
3212 92552 : newcasewhen->expr = (Expr *) casecond;
3213 92552 : newcasewhen->result = (Expr *) caseresult;
3214 92552 : newcasewhen->location = oldcasewhen->location;
3215 92552 : newargs = lappend(newargs, newcasewhen);
3216 92552 : continue;
3217 : }
3218 :
3219 : /*
3220 : * Found a TRUE condition, so none of the remaining
3221 : * alternatives can be reached. We treat the result as
3222 : * the default result.
3223 : */
3224 320 : defresult = caseresult;
3225 320 : break;
3226 : }
3227 :
3228 : /* Simplify the default result, unless we replaced it above */
3229 51306 : if (!const_true_cond)
3230 50986 : defresult = eval_const_expressions_mutator((Node *) caseexpr->defresult,
3231 : context);
3232 :
3233 51306 : context->case_val = save_case_val;
3234 :
3235 : /*
3236 : * If no non-FALSE alternatives, CASE reduces to the default
3237 : * result
3238 : */
3239 51306 : if (newargs == NIL)
3240 536 : return defresult;
3241 : /* Otherwise we need a new CASE node */
3242 50770 : newcase = makeNode(CaseExpr);
3243 50770 : newcase->casetype = caseexpr->casetype;
3244 50770 : newcase->casecollid = caseexpr->casecollid;
3245 50770 : newcase->arg = (Expr *) newarg;
3246 50770 : newcase->args = newargs;
3247 50770 : newcase->defresult = (Expr *) defresult;
3248 50770 : newcase->location = caseexpr->location;
3249 50770 : return (Node *) newcase;
3250 : }
3251 29286 : case T_CaseTestExpr:
3252 : {
3253 : /*
3254 : * If we know a constant test value for the current CASE
3255 : * construct, substitute it for the placeholder. Else just
3256 : * return the placeholder as-is.
3257 : */
3258 29286 : if (context->case_val)
3259 24 : return copyObject(context->case_val);
3260 : else
3261 29262 : return copyObject(node);
3262 : }
3263 55412 : case T_SubscriptingRef:
3264 : case T_ArrayExpr:
3265 : case T_RowExpr:
3266 : case T_MinMaxExpr:
3267 : {
3268 : /*
3269 : * Generic handling for node types whose own processing is
3270 : * known to be immutable, and for which we need no smarts
3271 : * beyond "simplify if all inputs are constants".
3272 : *
3273 : * Treating SubscriptingRef this way assumes that subscripting
3274 : * fetch and assignment are both immutable. This constrains
3275 : * type-specific subscripting implementations; maybe we should
3276 : * relax it someday.
3277 : *
3278 : * Treating MinMaxExpr this way amounts to assuming that the
3279 : * btree comparison function it calls is immutable; see the
3280 : * reasoning in contain_mutable_functions_walker.
3281 : */
3282 :
3283 : /* Copy the node and const-simplify its arguments */
3284 55412 : node = ece_generic_processing(node);
3285 : /* If all arguments are Consts, we can fold to a constant */
3286 55412 : if (ece_all_arguments_const(node))
3287 29434 : return ece_evaluate_expr(node);
3288 25978 : return node;
3289 : }
3290 2226 : case T_CoalesceExpr:
3291 : {
3292 2226 : CoalesceExpr *coalesceexpr = (CoalesceExpr *) node;
3293 : CoalesceExpr *newcoalesce;
3294 : List *newargs;
3295 : ListCell *arg;
3296 :
3297 2226 : newargs = NIL;
3298 5448 : foreach(arg, coalesceexpr->args)
3299 : {
3300 : Node *e;
3301 :
3302 4386 : e = eval_const_expressions_mutator((Node *) lfirst(arg),
3303 : context);
3304 :
3305 : /*
3306 : * We can remove null constants from the list. For a
3307 : * non-null constant, if it has not been preceded by any
3308 : * other non-null-constant expressions then it is the
3309 : * result. Otherwise, it's the next argument, but we can
3310 : * drop following arguments since they will never be
3311 : * reached.
3312 : */
3313 4386 : if (IsA(e, Const))
3314 : {
3315 1202 : if (((Const *) e)->constisnull)
3316 38 : continue; /* drop null constant */
3317 1164 : if (newargs == NIL)
3318 74 : return e; /* first expr */
3319 1090 : newargs = lappend(newargs, e);
3320 1090 : break;
3321 : }
3322 3184 : newargs = lappend(newargs, e);
3323 : }
3324 :
3325 : /*
3326 : * If all the arguments were constant null, the result is just
3327 : * null
3328 : */
3329 2152 : if (newargs == NIL)
3330 0 : return (Node *) makeNullConst(coalesceexpr->coalescetype,
3331 : -1,
3332 : coalesceexpr->coalescecollid);
3333 :
3334 2152 : newcoalesce = makeNode(CoalesceExpr);
3335 2152 : newcoalesce->coalescetype = coalesceexpr->coalescetype;
3336 2152 : newcoalesce->coalescecollid = coalesceexpr->coalescecollid;
3337 2152 : newcoalesce->args = newargs;
3338 2152 : newcoalesce->location = coalesceexpr->location;
3339 2152 : return (Node *) newcoalesce;
3340 : }
3341 4858 : case T_SQLValueFunction:
3342 : {
3343 : /*
3344 : * All variants of SQLValueFunction are stable, so if we are
3345 : * estimating the expression's value, we should evaluate the
3346 : * current function value. Otherwise just copy.
3347 : */
3348 4858 : SQLValueFunction *svf = (SQLValueFunction *) node;
3349 :
3350 4858 : if (context->estimate)
3351 786 : return (Node *) evaluate_expr((Expr *) svf,
3352 : svf->type,
3353 : svf->typmod,
3354 : InvalidOid);
3355 : else
3356 4072 : return copyObject((Node *) svf);
3357 : }
3358 5376 : case T_FieldSelect:
3359 : {
3360 : /*
3361 : * We can optimize field selection from a whole-row Var into a
3362 : * simple Var. (This case won't be generated directly by the
3363 : * parser, because ParseComplexProjection short-circuits it.
3364 : * But it can arise while simplifying functions.) Also, we
3365 : * can optimize field selection from a RowExpr construct, or
3366 : * of course from a constant.
3367 : *
3368 : * However, replacing a whole-row Var in this way has a
3369 : * pitfall: if we've already built the rel targetlist for the
3370 : * source relation, then the whole-row Var is scheduled to be
3371 : * produced by the relation scan, but the simple Var probably
3372 : * isn't, which will lead to a failure in setrefs.c. This is
3373 : * not a problem when handling simple single-level queries, in
3374 : * which expression simplification always happens first. It
3375 : * is a risk for lateral references from subqueries, though.
3376 : * To avoid such failures, don't optimize uplevel references.
3377 : *
3378 : * We must also check that the declared type of the field is
3379 : * still the same as when the FieldSelect was created --- this
3380 : * can change if someone did ALTER COLUMN TYPE on the rowtype.
3381 : * If it isn't, we skip the optimization; the case will
3382 : * probably fail at runtime, but that's not our problem here.
3383 : */
3384 5376 : FieldSelect *fselect = (FieldSelect *) node;
3385 : FieldSelect *newfselect;
3386 : Node *arg;
3387 :
3388 5376 : arg = eval_const_expressions_mutator((Node *) fselect->arg,
3389 : context);
3390 5376 : if (arg && IsA(arg, Var) &&
3391 1482 : ((Var *) arg)->varattno == InvalidAttrNumber &&
3392 90 : ((Var *) arg)->varlevelsup == 0)
3393 : {
3394 78 : if (rowtype_field_matches(((Var *) arg)->vartype,
3395 78 : fselect->fieldnum,
3396 : fselect->resulttype,
3397 : fselect->resulttypmod,
3398 : fselect->resultcollid))
3399 : {
3400 : Var *newvar;
3401 :
3402 78 : newvar = makeVar(((Var *) arg)->varno,
3403 78 : fselect->fieldnum,
3404 : fselect->resulttype,
3405 : fselect->resulttypmod,
3406 : fselect->resultcollid,
3407 : ((Var *) arg)->varlevelsup);
3408 : /* New Var is nullable by same rels as the old one */
3409 78 : newvar->varnullingrels = ((Var *) arg)->varnullingrels;
3410 78 : return (Node *) newvar;
3411 : }
3412 : }
3413 5298 : if (arg && IsA(arg, RowExpr))
3414 : {
3415 24 : RowExpr *rowexpr = (RowExpr *) arg;
3416 :
3417 48 : if (fselect->fieldnum > 0 &&
3418 24 : fselect->fieldnum <= list_length(rowexpr->args))
3419 : {
3420 24 : Node *fld = (Node *) list_nth(rowexpr->args,
3421 24 : fselect->fieldnum - 1);
3422 :
3423 24 : if (rowtype_field_matches(rowexpr->row_typeid,
3424 24 : fselect->fieldnum,
3425 : fselect->resulttype,
3426 : fselect->resulttypmod,
3427 24 : fselect->resultcollid) &&
3428 48 : fselect->resulttype == exprType(fld) &&
3429 48 : fselect->resulttypmod == exprTypmod(fld) &&
3430 24 : fselect->resultcollid == exprCollation(fld))
3431 24 : return fld;
3432 : }
3433 : }
3434 5274 : newfselect = makeNode(FieldSelect);
3435 5274 : newfselect->arg = (Expr *) arg;
3436 5274 : newfselect->fieldnum = fselect->fieldnum;
3437 5274 : newfselect->resulttype = fselect->resulttype;
3438 5274 : newfselect->resulttypmod = fselect->resulttypmod;
3439 5274 : newfselect->resultcollid = fselect->resultcollid;
3440 5274 : if (arg && IsA(arg, Const))
3441 : {
3442 424 : Const *con = (Const *) arg;
3443 :
3444 424 : if (rowtype_field_matches(con->consttype,
3445 424 : newfselect->fieldnum,
3446 : newfselect->resulttype,
3447 : newfselect->resulttypmod,
3448 : newfselect->resultcollid))
3449 424 : return ece_evaluate_expr(newfselect);
3450 : }
3451 4850 : return (Node *) newfselect;
3452 : }
3453 32172 : case T_NullTest:
3454 : {
3455 32172 : NullTest *ntest = (NullTest *) node;
3456 : NullTest *newntest;
3457 : Node *arg;
3458 :
3459 32172 : arg = eval_const_expressions_mutator((Node *) ntest->arg,
3460 : context);
3461 32170 : if (ntest->argisrow && arg && IsA(arg, RowExpr))
3462 : {
3463 : /*
3464 : * We break ROW(...) IS [NOT] NULL into separate tests on
3465 : * its component fields. This form is usually more
3466 : * efficient to evaluate, as well as being more amenable
3467 : * to optimization.
3468 : */
3469 30 : RowExpr *rarg = (RowExpr *) arg;
3470 30 : List *newargs = NIL;
3471 : ListCell *l;
3472 :
3473 120 : foreach(l, rarg->args)
3474 : {
3475 90 : Node *relem = (Node *) lfirst(l);
3476 :
3477 : /*
3478 : * A constant field refutes the whole NullTest if it's
3479 : * of the wrong nullness; else we can discard it.
3480 : */
3481 90 : if (relem && IsA(relem, Const))
3482 : {
3483 0 : Const *carg = (Const *) relem;
3484 :
3485 0 : if (carg->constisnull ?
3486 0 : (ntest->nulltesttype == IS_NOT_NULL) :
3487 0 : (ntest->nulltesttype == IS_NULL))
3488 0 : return makeBoolConst(false, false);
3489 0 : continue;
3490 : }
3491 :
3492 : /*
3493 : * Else, make a scalar (argisrow == false) NullTest
3494 : * for this field. Scalar semantics are required
3495 : * because IS [NOT] NULL doesn't recurse; see comments
3496 : * in ExecEvalRowNullInt().
3497 : */
3498 90 : newntest = makeNode(NullTest);
3499 90 : newntest->arg = (Expr *) relem;
3500 90 : newntest->nulltesttype = ntest->nulltesttype;
3501 90 : newntest->argisrow = false;
3502 90 : newntest->location = ntest->location;
3503 90 : newargs = lappend(newargs, newntest);
3504 : }
3505 : /* If all the inputs were constants, result is TRUE */
3506 30 : if (newargs == NIL)
3507 0 : return makeBoolConst(true, false);
3508 : /* If only one nonconst input, it's the result */
3509 30 : if (list_length(newargs) == 1)
3510 0 : return (Node *) linitial(newargs);
3511 : /* Else we need an AND node */
3512 30 : return (Node *) make_andclause(newargs);
3513 : }
3514 32140 : if (!ntest->argisrow && arg && IsA(arg, Const))
3515 : {
3516 372 : Const *carg = (Const *) arg;
3517 : bool result;
3518 :
3519 372 : switch (ntest->nulltesttype)
3520 : {
3521 312 : case IS_NULL:
3522 312 : result = carg->constisnull;
3523 312 : break;
3524 60 : case IS_NOT_NULL:
3525 60 : result = !carg->constisnull;
3526 60 : break;
3527 0 : default:
3528 0 : elog(ERROR, "unrecognized nulltesttype: %d",
3529 : (int) ntest->nulltesttype);
3530 : result = false; /* keep compiler quiet */
3531 : break;
3532 : }
3533 :
3534 372 : return makeBoolConst(result, false);
3535 : }
3536 :
3537 31768 : newntest = makeNode(NullTest);
3538 31768 : newntest->arg = (Expr *) arg;
3539 31768 : newntest->nulltesttype = ntest->nulltesttype;
3540 31768 : newntest->argisrow = ntest->argisrow;
3541 31768 : newntest->location = ntest->location;
3542 31768 : return (Node *) newntest;
3543 : }
3544 1814 : case T_BooleanTest:
3545 : {
3546 : /*
3547 : * This case could be folded into the generic handling used
3548 : * for ArrayExpr etc. But because the simplification logic is
3549 : * so trivial, applying evaluate_expr() to perform it would be
3550 : * a heavy overhead. BooleanTest is probably common enough to
3551 : * justify keeping this bespoke implementation.
3552 : */
3553 1814 : BooleanTest *btest = (BooleanTest *) node;
3554 : BooleanTest *newbtest;
3555 : Node *arg;
3556 :
3557 1814 : arg = eval_const_expressions_mutator((Node *) btest->arg,
3558 : context);
3559 1814 : if (arg && IsA(arg, Const))
3560 : {
3561 222 : Const *carg = (Const *) arg;
3562 : bool result;
3563 :
3564 222 : switch (btest->booltesttype)
3565 : {
3566 0 : case IS_TRUE:
3567 0 : result = (!carg->constisnull &&
3568 0 : DatumGetBool(carg->constvalue));
3569 0 : break;
3570 222 : case IS_NOT_TRUE:
3571 444 : result = (carg->constisnull ||
3572 222 : !DatumGetBool(carg->constvalue));
3573 222 : break;
3574 0 : case IS_FALSE:
3575 0 : result = (!carg->constisnull &&
3576 0 : !DatumGetBool(carg->constvalue));
3577 0 : break;
3578 0 : case IS_NOT_FALSE:
3579 0 : result = (carg->constisnull ||
3580 0 : DatumGetBool(carg->constvalue));
3581 0 : break;
3582 0 : case IS_UNKNOWN:
3583 0 : result = carg->constisnull;
3584 0 : break;
3585 0 : case IS_NOT_UNKNOWN:
3586 0 : result = !carg->constisnull;
3587 0 : break;
3588 0 : default:
3589 0 : elog(ERROR, "unrecognized booltesttype: %d",
3590 : (int) btest->booltesttype);
3591 : result = false; /* keep compiler quiet */
3592 : break;
3593 : }
3594 :
3595 222 : return makeBoolConst(result, false);
3596 : }
3597 :
3598 1592 : newbtest = makeNode(BooleanTest);
3599 1592 : newbtest->arg = (Expr *) arg;
3600 1592 : newbtest->booltesttype = btest->booltesttype;
3601 1592 : newbtest->location = btest->location;
3602 1592 : return (Node *) newbtest;
3603 : }
3604 25496 : case T_CoerceToDomain:
3605 : {
3606 : /*
3607 : * If the domain currently has no constraints, we replace the
3608 : * CoerceToDomain node with a simple RelabelType, which is
3609 : * both far faster to execute and more amenable to later
3610 : * optimization. We must then mark the plan as needing to be
3611 : * rebuilt if the domain's constraints change.
3612 : *
3613 : * Also, in estimation mode, always replace CoerceToDomain
3614 : * nodes, effectively assuming that the coercion will succeed.
3615 : */
3616 25496 : CoerceToDomain *cdomain = (CoerceToDomain *) node;
3617 : CoerceToDomain *newcdomain;
3618 : Node *arg;
3619 :
3620 25496 : arg = eval_const_expressions_mutator((Node *) cdomain->arg,
3621 : context);
3622 25466 : if (context->estimate ||
3623 25442 : !DomainHasConstraints(cdomain->resulttype))
3624 : {
3625 : /* Record dependency, if this isn't estimation mode */
3626 16698 : if (context->root && !context->estimate)
3627 16632 : record_plan_type_dependency(context->root,
3628 : cdomain->resulttype);
3629 :
3630 : /* Generate RelabelType to substitute for CoerceToDomain */
3631 16698 : return applyRelabelType(arg,
3632 : cdomain->resulttype,
3633 : cdomain->resulttypmod,
3634 : cdomain->resultcollid,
3635 : cdomain->coercionformat,
3636 : cdomain->location,
3637 : true);
3638 : }
3639 :
3640 8768 : newcdomain = makeNode(CoerceToDomain);
3641 8768 : newcdomain->arg = (Expr *) arg;
3642 8768 : newcdomain->resulttype = cdomain->resulttype;
3643 8768 : newcdomain->resulttypmod = cdomain->resulttypmod;
3644 8768 : newcdomain->resultcollid = cdomain->resultcollid;
3645 8768 : newcdomain->coercionformat = cdomain->coercionformat;
3646 8768 : newcdomain->location = cdomain->location;
3647 8768 : return (Node *) newcdomain;
3648 : }
3649 2640 : case T_PlaceHolderVar:
3650 :
3651 : /*
3652 : * In estimation mode, just strip the PlaceHolderVar node
3653 : * altogether; this amounts to estimating that the contained value
3654 : * won't be forced to null by an outer join. In regular mode we
3655 : * just use the default behavior (ie, simplify the expression but
3656 : * leave the PlaceHolderVar node intact).
3657 : */
3658 2640 : if (context->estimate)
3659 : {
3660 744 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
3661 :
3662 744 : return eval_const_expressions_mutator((Node *) phv->phexpr,
3663 : context);
3664 : }
3665 1896 : break;
3666 78 : case T_ConvertRowtypeExpr:
3667 : {
3668 78 : ConvertRowtypeExpr *cre = castNode(ConvertRowtypeExpr, node);
3669 : Node *arg;
3670 : ConvertRowtypeExpr *newcre;
3671 :
3672 78 : arg = eval_const_expressions_mutator((Node *) cre->arg,
3673 : context);
3674 :
3675 78 : newcre = makeNode(ConvertRowtypeExpr);
3676 78 : newcre->resulttype = cre->resulttype;
3677 78 : newcre->convertformat = cre->convertformat;
3678 78 : newcre->location = cre->location;
3679 :
3680 : /*
3681 : * In case of a nested ConvertRowtypeExpr, we can convert the
3682 : * leaf row directly to the topmost row format without any
3683 : * intermediate conversions. (This works because
3684 : * ConvertRowtypeExpr is used only for child->parent
3685 : * conversion in inheritance trees, which works by exact match
3686 : * of column name, and a column absent in an intermediate
3687 : * result can't be present in the final result.)
3688 : *
3689 : * No need to check more than one level deep, because the
3690 : * above recursion will have flattened anything else.
3691 : */
3692 78 : if (arg != NULL && IsA(arg, ConvertRowtypeExpr))
3693 : {
3694 12 : ConvertRowtypeExpr *argcre = (ConvertRowtypeExpr *) arg;
3695 :
3696 12 : arg = (Node *) argcre->arg;
3697 :
3698 : /*
3699 : * Make sure an outer implicit conversion can't hide an
3700 : * inner explicit one.
3701 : */
3702 12 : if (newcre->convertformat == COERCE_IMPLICIT_CAST)
3703 0 : newcre->convertformat = argcre->convertformat;
3704 : }
3705 :
3706 78 : newcre->arg = (Expr *) arg;
3707 :
3708 78 : if (arg != NULL && IsA(arg, Const))
3709 18 : return ece_evaluate_expr((Node *) newcre);
3710 60 : return (Node *) newcre;
3711 : }
3712 5915758 : default:
3713 5915758 : break;
3714 : }
3715 :
3716 : /*
3717 : * For any node type not handled above, copy the node unchanged but
3718 : * const-simplify its subexpressions. This is the correct thing for node
3719 : * types whose behavior might change between planning and execution, such
3720 : * as CurrentOfExpr. It's also a safe default for new node types not
3721 : * known to this routine.
3722 : */
3723 5917654 : return ece_generic_processing(node);
3724 : }
3725 :
3726 : /*
3727 : * Subroutine for eval_const_expressions: check for non-Const nodes.
3728 : *
3729 : * We can abort recursion immediately on finding a non-Const node. This is
3730 : * critical for performance, else eval_const_expressions_mutator would take
3731 : * O(N^2) time on non-simplifiable trees. However, we do need to descend
3732 : * into List nodes since expression_tree_walker sometimes invokes the walker
3733 : * function directly on List subtrees.
3734 : */
3735 : static bool
3736 196520 : contain_non_const_walker(Node *node, void *context)
3737 : {
3738 196520 : if (node == NULL)
3739 598 : return false;
3740 195922 : if (IsA(node, Const))
3741 100140 : return false;
3742 95782 : if (IsA(node, List))
3743 34408 : return expression_tree_walker(node, contain_non_const_walker, context);
3744 : /* Otherwise, abort the tree traversal and return true */
3745 61374 : return true;
3746 : }
3747 :
3748 : /*
3749 : * Subroutine for eval_const_expressions: check if a function is OK to evaluate
3750 : */
3751 : static bool
3752 230 : ece_function_is_safe(Oid funcid, eval_const_expressions_context *context)
3753 : {
3754 230 : char provolatile = func_volatile(funcid);
3755 :
3756 : /*
3757 : * Ordinarily we are only allowed to simplify immutable functions. But for
3758 : * purposes of estimation, we consider it okay to simplify functions that
3759 : * are merely stable; the risk that the result might change from planning
3760 : * time to execution time is worth taking in preference to not being able
3761 : * to estimate the value at all.
3762 : */
3763 230 : if (provolatile == PROVOLATILE_IMMUTABLE)
3764 230 : return true;
3765 0 : if (context->estimate && provolatile == PROVOLATILE_STABLE)
3766 0 : return true;
3767 0 : return false;
3768 : }
3769 :
3770 : /*
3771 : * Subroutine for eval_const_expressions: process arguments of an OR clause
3772 : *
3773 : * This includes flattening of nested ORs as well as recursion to
3774 : * eval_const_expressions to simplify the OR arguments.
3775 : *
3776 : * After simplification, OR arguments are handled as follows:
3777 : * non constant: keep
3778 : * FALSE: drop (does not affect result)
3779 : * TRUE: force result to TRUE
3780 : * NULL: keep only one
3781 : * We must keep one NULL input because OR expressions evaluate to NULL when no
3782 : * input is TRUE and at least one is NULL. We don't actually include the NULL
3783 : * here, that's supposed to be done by the caller.
3784 : *
3785 : * The output arguments *haveNull and *forceTrue must be initialized false
3786 : * by the caller. They will be set true if a NULL constant or TRUE constant,
3787 : * respectively, is detected anywhere in the argument list.
3788 : */
3789 : static List *
3790 13986 : simplify_or_arguments(List *args,
3791 : eval_const_expressions_context *context,
3792 : bool *haveNull, bool *forceTrue)
3793 : {
3794 13986 : List *newargs = NIL;
3795 : List *unprocessed_args;
3796 :
3797 : /*
3798 : * We want to ensure that any OR immediately beneath another OR gets
3799 : * flattened into a single OR-list, so as to simplify later reasoning.
3800 : *
3801 : * To avoid stack overflow from recursion of eval_const_expressions, we
3802 : * resort to some tenseness here: we keep a list of not-yet-processed
3803 : * inputs, and handle flattening of nested ORs by prepending to the to-do
3804 : * list instead of recursing. Now that the parser generates N-argument
3805 : * ORs from simple lists, this complexity is probably less necessary than
3806 : * it once was, but we might as well keep the logic.
3807 : */
3808 13986 : unprocessed_args = list_copy(args);
3809 46126 : while (unprocessed_args)
3810 : {
3811 32288 : Node *arg = (Node *) linitial(unprocessed_args);
3812 :
3813 32288 : unprocessed_args = list_delete_first(unprocessed_args);
3814 :
3815 : /* flatten nested ORs as per above comment */
3816 32288 : if (is_orclause(arg))
3817 : {
3818 6 : List *subargs = ((BoolExpr *) arg)->args;
3819 6 : List *oldlist = unprocessed_args;
3820 :
3821 6 : unprocessed_args = list_concat_copy(subargs, unprocessed_args);
3822 : /* perhaps-overly-tense code to avoid leaking old lists */
3823 6 : list_free(oldlist);
3824 6 : continue;
3825 : }
3826 :
3827 : /* If it's not an OR, simplify it */
3828 32282 : arg = eval_const_expressions_mutator(arg, context);
3829 :
3830 : /*
3831 : * It is unlikely but not impossible for simplification of a non-OR
3832 : * clause to produce an OR. Recheck, but don't be too tense about it
3833 : * since it's not a mainstream case. In particular we don't worry
3834 : * about const-simplifying the input twice, nor about list leakage.
3835 : */
3836 32282 : if (is_orclause(arg))
3837 : {
3838 0 : List *subargs = ((BoolExpr *) arg)->args;
3839 :
3840 0 : unprocessed_args = list_concat_copy(subargs, unprocessed_args);
3841 0 : continue;
3842 : }
3843 :
3844 : /*
3845 : * OK, we have a const-simplified non-OR argument. Process it per
3846 : * comments above.
3847 : */
3848 32282 : if (IsA(arg, Const))
3849 : {
3850 286 : Const *const_input = (Const *) arg;
3851 :
3852 286 : if (const_input->constisnull)
3853 48 : *haveNull = true;
3854 238 : else if (DatumGetBool(const_input->constvalue))
3855 : {
3856 148 : *forceTrue = true;
3857 :
3858 : /*
3859 : * Once we detect a TRUE result we can just exit the loop
3860 : * immediately. However, if we ever add a notion of
3861 : * non-removable functions, we'd need to keep scanning.
3862 : */
3863 148 : return NIL;
3864 : }
3865 : /* otherwise, we can drop the constant-false input */
3866 138 : continue;
3867 : }
3868 :
3869 : /* else emit the simplified arg into the result list */
3870 31996 : newargs = lappend(newargs, arg);
3871 : }
3872 :
3873 13838 : return newargs;
3874 : }
3875 :
3876 : /*
3877 : * Subroutine for eval_const_expressions: process arguments of an AND clause
3878 : *
3879 : * This includes flattening of nested ANDs as well as recursion to
3880 : * eval_const_expressions to simplify the AND arguments.
3881 : *
3882 : * After simplification, AND arguments are handled as follows:
3883 : * non constant: keep
3884 : * TRUE: drop (does not affect result)
3885 : * FALSE: force result to FALSE
3886 : * NULL: keep only one
3887 : * We must keep one NULL input because AND expressions evaluate to NULL when
3888 : * no input is FALSE and at least one is NULL. We don't actually include the
3889 : * NULL here, that's supposed to be done by the caller.
3890 : *
3891 : * The output arguments *haveNull and *forceFalse must be initialized false
3892 : * by the caller. They will be set true if a null constant or false constant,
3893 : * respectively, is detected anywhere in the argument list.
3894 : */
3895 : static List *
3896 130108 : simplify_and_arguments(List *args,
3897 : eval_const_expressions_context *context,
3898 : bool *haveNull, bool *forceFalse)
3899 : {
3900 130108 : List *newargs = NIL;
3901 : List *unprocessed_args;
3902 :
3903 : /* See comments in simplify_or_arguments */
3904 130108 : unprocessed_args = list_copy(args);
3905 480942 : while (unprocessed_args)
3906 : {
3907 352300 : Node *arg = (Node *) linitial(unprocessed_args);
3908 :
3909 352300 : unprocessed_args = list_delete_first(unprocessed_args);
3910 :
3911 : /* flatten nested ANDs as per above comment */
3912 352300 : if (is_andclause(arg))
3913 : {
3914 1762 : List *subargs = ((BoolExpr *) arg)->args;
3915 1762 : List *oldlist = unprocessed_args;
3916 :
3917 1762 : unprocessed_args = list_concat_copy(subargs, unprocessed_args);
3918 : /* perhaps-overly-tense code to avoid leaking old lists */
3919 1762 : list_free(oldlist);
3920 1762 : continue;
3921 : }
3922 :
3923 : /* If it's not an AND, simplify it */
3924 350538 : arg = eval_const_expressions_mutator(arg, context);
3925 :
3926 : /*
3927 : * It is unlikely but not impossible for simplification of a non-AND
3928 : * clause to produce an AND. Recheck, but don't be too tense about it
3929 : * since it's not a mainstream case. In particular we don't worry
3930 : * about const-simplifying the input twice, nor about list leakage.
3931 : */
3932 350538 : if (is_andclause(arg))
3933 : {
3934 30 : List *subargs = ((BoolExpr *) arg)->args;
3935 :
3936 30 : unprocessed_args = list_concat_copy(subargs, unprocessed_args);
3937 30 : continue;
3938 : }
3939 :
3940 : /*
3941 : * OK, we have a const-simplified non-AND argument. Process it per
3942 : * comments above.
3943 : */
3944 350508 : if (IsA(arg, Const))
3945 : {
3946 3152 : Const *const_input = (Const *) arg;
3947 :
3948 3152 : if (const_input->constisnull)
3949 18 : *haveNull = true;
3950 3134 : else if (!DatumGetBool(const_input->constvalue))
3951 : {
3952 1466 : *forceFalse = true;
3953 :
3954 : /*
3955 : * Once we detect a FALSE result we can just exit the loop
3956 : * immediately. However, if we ever add a notion of
3957 : * non-removable functions, we'd need to keep scanning.
3958 : */
3959 1466 : return NIL;
3960 : }
3961 : /* otherwise, we can drop the constant-true input */
3962 1686 : continue;
3963 : }
3964 :
3965 : /* else emit the simplified arg into the result list */
3966 347356 : newargs = lappend(newargs, arg);
3967 : }
3968 :
3969 128642 : return newargs;
3970 : }
3971 :
3972 : /*
3973 : * Subroutine for eval_const_expressions: try to simplify boolean equality
3974 : * or inequality condition
3975 : *
3976 : * Inputs are the operator OID and the simplified arguments to the operator.
3977 : * Returns a simplified expression if successful, or NULL if cannot
3978 : * simplify the expression.
3979 : *
3980 : * The idea here is to reduce "x = true" to "x" and "x = false" to "NOT x",
3981 : * or similarly "x <> true" to "NOT x" and "x <> false" to "x".
3982 : * This is only marginally useful in itself, but doing it in constant folding
3983 : * ensures that we will recognize these forms as being equivalent in, for
3984 : * example, partial index matching.
3985 : *
3986 : * We come here only if simplify_function has failed; therefore we cannot
3987 : * see two constant inputs, nor a constant-NULL input.
3988 : */
3989 : static Node *
3990 932 : simplify_boolean_equality(Oid opno, List *args)
3991 : {
3992 : Node *leftop;
3993 : Node *rightop;
3994 :
3995 : Assert(list_length(args) == 2);
3996 932 : leftop = linitial(args);
3997 932 : rightop = lsecond(args);
3998 932 : if (leftop && IsA(leftop, Const))
3999 : {
4000 : Assert(!((Const *) leftop)->constisnull);
4001 0 : if (opno == BooleanEqualOperator)
4002 : {
4003 0 : if (DatumGetBool(((Const *) leftop)->constvalue))
4004 0 : return rightop; /* true = foo */
4005 : else
4006 0 : return negate_clause(rightop); /* false = foo */
4007 : }
4008 : else
4009 : {
4010 0 : if (DatumGetBool(((Const *) leftop)->constvalue))
4011 0 : return negate_clause(rightop); /* true <> foo */
4012 : else
4013 0 : return rightop; /* false <> foo */
4014 : }
4015 : }
4016 932 : if (rightop && IsA(rightop, Const))
4017 : {
4018 : Assert(!((Const *) rightop)->constisnull);
4019 754 : if (opno == BooleanEqualOperator)
4020 : {
4021 688 : if (DatumGetBool(((Const *) rightop)->constvalue))
4022 176 : return leftop; /* foo = true */
4023 : else
4024 512 : return negate_clause(leftop); /* foo = false */
4025 : }
4026 : else
4027 : {
4028 66 : if (DatumGetBool(((Const *) rightop)->constvalue))
4029 60 : return negate_clause(leftop); /* foo <> true */
4030 : else
4031 6 : return leftop; /* foo <> false */
4032 : }
4033 : }
4034 178 : return NULL;
4035 : }
4036 :
4037 : /*
4038 : * Subroutine for eval_const_expressions: try to simplify a function call
4039 : * (which might originally have been an operator; we don't care)
4040 : *
4041 : * Inputs are the function OID, actual result type OID (which is needed for
4042 : * polymorphic functions), result typmod, result collation, the input
4043 : * collation to use for the function, the original argument list (not
4044 : * const-simplified yet, unless process_args is false), and some flags;
4045 : * also the context data for eval_const_expressions.
4046 : *
4047 : * Returns a simplified expression if successful, or NULL if cannot
4048 : * simplify the function call.
4049 : *
4050 : * This function is also responsible for converting named-notation argument
4051 : * lists into positional notation and/or adding any needed default argument
4052 : * expressions; which is a bit grotty, but it avoids extra fetches of the
4053 : * function's pg_proc tuple. For this reason, the args list is
4054 : * pass-by-reference. Conversion and const-simplification of the args list
4055 : * will be done even if simplification of the function call itself is not
4056 : * possible.
4057 : */
4058 : static Expr *
4059 1219956 : simplify_function(Oid funcid, Oid result_type, int32 result_typmod,
4060 : Oid result_collid, Oid input_collid, List **args_p,
4061 : bool funcvariadic, bool process_args, bool allow_non_const,
4062 : eval_const_expressions_context *context)
4063 : {
4064 1219956 : List *args = *args_p;
4065 : HeapTuple func_tuple;
4066 : Form_pg_proc func_form;
4067 : Expr *newexpr;
4068 :
4069 : /*
4070 : * We have three strategies for simplification: execute the function to
4071 : * deliver a constant result, use a transform function to generate a
4072 : * substitute node tree, or expand in-line the body of the function
4073 : * definition (which only works for simple SQL-language functions, but
4074 : * that is a common case). Each case needs access to the function's
4075 : * pg_proc tuple, so fetch it just once.
4076 : *
4077 : * Note: the allow_non_const flag suppresses both the second and third
4078 : * strategies; so if !allow_non_const, simplify_function can only return a
4079 : * Const or NULL. Argument-list rewriting happens anyway, though.
4080 : */
4081 1219956 : func_tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
4082 1219956 : if (!HeapTupleIsValid(func_tuple))
4083 0 : elog(ERROR, "cache lookup failed for function %u", funcid);
4084 1219956 : func_form = (Form_pg_proc) GETSTRUCT(func_tuple);
4085 :
4086 : /*
4087 : * Process the function arguments, unless the caller did it already.
4088 : *
4089 : * Here we must deal with named or defaulted arguments, and then
4090 : * recursively apply eval_const_expressions to the whole argument list.
4091 : */
4092 1219956 : if (process_args)
4093 : {
4094 1217868 : args = expand_function_arguments(args, false, result_type, func_tuple);
4095 1217868 : args = (List *) expression_tree_mutator((Node *) args,
4096 : eval_const_expressions_mutator,
4097 : (void *) context);
4098 : /* Argument processing done, give it back to the caller */
4099 1217772 : *args_p = args;
4100 : }
4101 :
4102 : /* Now attempt simplification of the function call proper. */
4103 :
4104 1219860 : newexpr = evaluate_function(funcid, result_type, result_typmod,
4105 : result_collid, input_collid,
4106 : args, funcvariadic,
4107 : func_tuple, context);
4108 :
4109 1216270 : if (!newexpr && allow_non_const && OidIsValid(func_form->prosupport))
4110 : {
4111 : /*
4112 : * Build a SupportRequestSimplify node to pass to the support
4113 : * function, pointing to a dummy FuncExpr node containing the
4114 : * simplified arg list. We use this approach to present a uniform
4115 : * interface to the support function regardless of how the target
4116 : * function is actually being invoked.
4117 : */
4118 : SupportRequestSimplify req;
4119 : FuncExpr fexpr;
4120 :
4121 30842 : fexpr.xpr.type = T_FuncExpr;
4122 30842 : fexpr.funcid = funcid;
4123 30842 : fexpr.funcresulttype = result_type;
4124 30842 : fexpr.funcretset = func_form->proretset;
4125 30842 : fexpr.funcvariadic = funcvariadic;
4126 30842 : fexpr.funcformat = COERCE_EXPLICIT_CALL;
4127 30842 : fexpr.funccollid = result_collid;
4128 30842 : fexpr.inputcollid = input_collid;
4129 30842 : fexpr.args = args;
4130 30842 : fexpr.location = -1;
4131 :
4132 30842 : req.type = T_SupportRequestSimplify;
4133 30842 : req.root = context->root;
4134 30842 : req.fcall = &fexpr;
4135 :
4136 : newexpr = (Expr *)
4137 30842 : DatumGetPointer(OidFunctionCall1(func_form->prosupport,
4138 : PointerGetDatum(&req)));
4139 :
4140 : /* catch a possible API misunderstanding */
4141 : Assert(newexpr != (Expr *) &fexpr);
4142 : }
4143 :
4144 1216270 : if (!newexpr && allow_non_const)
4145 1043594 : newexpr = inline_function(funcid, result_type, result_collid,
4146 : input_collid, args, funcvariadic,
4147 : func_tuple, context);
4148 :
4149 1216250 : ReleaseSysCache(func_tuple);
4150 :
4151 1216250 : return newexpr;
4152 : }
4153 :
4154 : /*
4155 : * expand_function_arguments: convert named-notation args to positional args
4156 : * and/or insert default args, as needed
4157 : *
4158 : * Returns a possibly-transformed version of the args list.
4159 : *
4160 : * If include_out_arguments is true, then the args list and the result
4161 : * include OUT arguments.
4162 : *
4163 : * The expected result type of the call must be given, for sanity-checking
4164 : * purposes. Also, we ask the caller to provide the function's actual
4165 : * pg_proc tuple, not just its OID.
4166 : *
4167 : * If we need to change anything, the input argument list is copied, not
4168 : * modified.
4169 : *
4170 : * Note: this gets applied to operator argument lists too, even though the
4171 : * cases it handles should never occur there. This should be OK since it
4172 : * will fall through very quickly if there's nothing to do.
4173 : */
4174 : List *
4175 1221498 : expand_function_arguments(List *args, bool include_out_arguments,
4176 : Oid result_type, HeapTuple func_tuple)
4177 : {
4178 1221498 : Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
4179 1221498 : Oid *proargtypes = funcform->proargtypes.values;
4180 1221498 : int pronargs = funcform->pronargs;
4181 1221498 : bool has_named_args = false;
4182 : ListCell *lc;
4183 :
4184 : /*
4185 : * If we are asked to match to OUT arguments, then use the proallargtypes
4186 : * array (which includes those); otherwise use proargtypes (which
4187 : * doesn't). Of course, if proallargtypes is null, we always use
4188 : * proargtypes. (Fetching proallargtypes is annoyingly expensive
4189 : * considering that we may have nothing to do here, but fortunately the
4190 : * common case is include_out_arguments == false.)
4191 : */
4192 1221498 : if (include_out_arguments)
4193 : {
4194 : Datum proallargtypes;
4195 : bool isNull;
4196 :
4197 472 : proallargtypes = SysCacheGetAttr(PROCOID, func_tuple,
4198 : Anum_pg_proc_proallargtypes,
4199 : &isNull);
4200 472 : if (!isNull)
4201 : {
4202 202 : ArrayType *arr = DatumGetArrayTypeP(proallargtypes);
4203 :
4204 202 : pronargs = ARR_DIMS(arr)[0];
4205 202 : if (ARR_NDIM(arr) != 1 ||
4206 202 : pronargs < 0 ||
4207 202 : ARR_HASNULL(arr) ||
4208 202 : ARR_ELEMTYPE(arr) != OIDOID)
4209 0 : elog(ERROR, "proallargtypes is not a 1-D Oid array or it contains nulls");
4210 : Assert(pronargs >= funcform->pronargs);
4211 202 : proargtypes = (Oid *) ARR_DATA_PTR(arr);
4212 : }
4213 : }
4214 :
4215 : /* Do we have any named arguments? */
4216 3222544 : foreach(lc, args)
4217 : {
4218 2018460 : Node *arg = (Node *) lfirst(lc);
4219 :
4220 2018460 : if (IsA(arg, NamedArgExpr))
4221 : {
4222 17414 : has_named_args = true;
4223 17414 : break;
4224 : }
4225 : }
4226 :
4227 : /* If so, we must apply reorder_function_arguments */
4228 1221498 : if (has_named_args)
4229 : {
4230 17414 : args = reorder_function_arguments(args, pronargs, func_tuple);
4231 : /* Recheck argument types and add casts if needed */
4232 17414 : recheck_cast_function_args(args, result_type,
4233 : proargtypes, pronargs,
4234 : func_tuple);
4235 : }
4236 1204084 : else if (list_length(args) < pronargs)
4237 : {
4238 : /* No named args, but we seem to be short some defaults */
4239 5982 : args = add_function_defaults(args, pronargs, func_tuple);
4240 : /* Recheck argument types and add casts if needed */
4241 5982 : recheck_cast_function_args(args, result_type,
4242 : proargtypes, pronargs,
4243 : func_tuple);
4244 : }
4245 :
4246 1221498 : return args;
4247 : }
4248 :
4249 : /*
4250 : * reorder_function_arguments: convert named-notation args to positional args
4251 : *
4252 : * This function also inserts default argument values as needed, since it's
4253 : * impossible to form a truly valid positional call without that.
4254 : */
4255 : static List *
4256 17414 : reorder_function_arguments(List *args, int pronargs, HeapTuple func_tuple)
4257 : {
4258 17414 : Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
4259 17414 : int nargsprovided = list_length(args);
4260 : Node *argarray[FUNC_MAX_ARGS];
4261 : ListCell *lc;
4262 : int i;
4263 :
4264 : Assert(nargsprovided <= pronargs);
4265 17414 : if (pronargs < 0 || pronargs > FUNC_MAX_ARGS)
4266 0 : elog(ERROR, "too many function arguments");
4267 17414 : memset(argarray, 0, pronargs * sizeof(Node *));
4268 :
4269 : /* Deconstruct the argument list into an array indexed by argnumber */
4270 17414 : i = 0;
4271 71624 : foreach(lc, args)
4272 : {
4273 54210 : Node *arg = (Node *) lfirst(lc);
4274 :
4275 54210 : if (!IsA(arg, NamedArgExpr))
4276 : {
4277 : /* positional argument, assumed to precede all named args */
4278 : Assert(argarray[i] == NULL);
4279 1852 : argarray[i++] = arg;
4280 : }
4281 : else
4282 : {
4283 52358 : NamedArgExpr *na = (NamedArgExpr *) arg;
4284 :
4285 : Assert(na->argnumber >= 0 && na->argnumber < pronargs);
4286 : Assert(argarray[na->argnumber] == NULL);
4287 52358 : argarray[na->argnumber] = (Node *) na->arg;
4288 : }
4289 : }
4290 :
4291 : /*
4292 : * Fetch default expressions, if needed, and insert into array at proper
4293 : * locations (they aren't necessarily consecutive or all used)
4294 : */
4295 17414 : if (nargsprovided < pronargs)
4296 : {
4297 8048 : List *defaults = fetch_function_defaults(func_tuple);
4298 :
4299 8048 : i = pronargs - funcform->pronargdefaults;
4300 47646 : foreach(lc, defaults)
4301 : {
4302 39598 : if (argarray[i] == NULL)
4303 17094 : argarray[i] = (Node *) lfirst(lc);
4304 39598 : i++;
4305 : }
4306 : }
4307 :
4308 : /* Now reconstruct the args list in proper order */
4309 17414 : args = NIL;
4310 88718 : for (i = 0; i < pronargs; i++)
4311 : {
4312 : Assert(argarray[i] != NULL);
4313 71304 : args = lappend(args, argarray[i]);
4314 : }
4315 :
4316 17414 : return args;
4317 : }
4318 :
4319 : /*
4320 : * add_function_defaults: add missing function arguments from its defaults
4321 : *
4322 : * This is used only when the argument list was positional to begin with,
4323 : * and so we know we just need to add defaults at the end.
4324 : */
4325 : static List *
4326 5982 : add_function_defaults(List *args, int pronargs, HeapTuple func_tuple)
4327 : {
4328 5982 : int nargsprovided = list_length(args);
4329 : List *defaults;
4330 : int ndelete;
4331 :
4332 : /* Get all the default expressions from the pg_proc tuple */
4333 5982 : defaults = fetch_function_defaults(func_tuple);
4334 :
4335 : /* Delete any unused defaults from the list */
4336 5982 : ndelete = nargsprovided + list_length(defaults) - pronargs;
4337 5982 : if (ndelete < 0)
4338 0 : elog(ERROR, "not enough default arguments");
4339 5982 : if (ndelete > 0)
4340 228 : defaults = list_delete_first_n(defaults, ndelete);
4341 :
4342 : /* And form the combined argument list, not modifying the input list */
4343 5982 : return list_concat_copy(args, defaults);
4344 : }
4345 :
4346 : /*
4347 : * fetch_function_defaults: get function's default arguments as expression list
4348 : */
4349 : static List *
4350 14030 : fetch_function_defaults(HeapTuple func_tuple)
4351 : {
4352 : List *defaults;
4353 : Datum proargdefaults;
4354 : char *str;
4355 :
4356 14030 : proargdefaults = SysCacheGetAttrNotNull(PROCOID, func_tuple,
4357 : Anum_pg_proc_proargdefaults);
4358 14030 : str = TextDatumGetCString(proargdefaults);
4359 14030 : defaults = castNode(List, stringToNode(str));
4360 14030 : pfree(str);
4361 14030 : return defaults;
4362 : }
4363 :
4364 : /*
4365 : * recheck_cast_function_args: recheck function args and typecast as needed
4366 : * after adding defaults.
4367 : *
4368 : * It is possible for some of the defaulted arguments to be polymorphic;
4369 : * therefore we can't assume that the default expressions have the correct
4370 : * data types already. We have to re-resolve polymorphics and do coercion
4371 : * just like the parser did.
4372 : *
4373 : * This should be a no-op if there are no polymorphic arguments,
4374 : * but we do it anyway to be sure.
4375 : *
4376 : * Note: if any casts are needed, the args list is modified in-place;
4377 : * caller should have already copied the list structure.
4378 : */
4379 : static void
4380 23396 : recheck_cast_function_args(List *args, Oid result_type,
4381 : Oid *proargtypes, int pronargs,
4382 : HeapTuple func_tuple)
4383 : {
4384 23396 : Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
4385 : int nargs;
4386 : Oid actual_arg_types[FUNC_MAX_ARGS];
4387 : Oid declared_arg_types[FUNC_MAX_ARGS];
4388 : Oid rettype;
4389 : ListCell *lc;
4390 :
4391 23396 : if (list_length(args) > FUNC_MAX_ARGS)
4392 0 : elog(ERROR, "too many function arguments");
4393 23396 : nargs = 0;
4394 117204 : foreach(lc, args)
4395 : {
4396 93808 : actual_arg_types[nargs++] = exprType((Node *) lfirst(lc));
4397 : }
4398 : Assert(nargs == pronargs);
4399 23396 : memcpy(declared_arg_types, proargtypes, pronargs * sizeof(Oid));
4400 23396 : rettype = enforce_generic_type_consistency(actual_arg_types,
4401 : declared_arg_types,
4402 : nargs,
4403 : funcform->prorettype,
4404 : false);
4405 : /* let's just check we got the same answer as the parser did ... */
4406 23396 : if (rettype != result_type)
4407 0 : elog(ERROR, "function's resolved result type changed during planning");
4408 :
4409 : /* perform any necessary typecasting of arguments */
4410 23396 : make_fn_arguments(NULL, args, actual_arg_types, declared_arg_types);
4411 23396 : }
4412 :
4413 : /*
4414 : * evaluate_function: try to pre-evaluate a function call
4415 : *
4416 : * We can do this if the function is strict and has any constant-null inputs
4417 : * (just return a null constant), or if the function is immutable and has all
4418 : * constant inputs (call it and return the result as a Const node). In
4419 : * estimation mode we are willing to pre-evaluate stable functions too.
4420 : *
4421 : * Returns a simplified expression if successful, or NULL if cannot
4422 : * simplify the function.
4423 : */
4424 : static Expr *
4425 1219860 : evaluate_function(Oid funcid, Oid result_type, int32 result_typmod,
4426 : Oid result_collid, Oid input_collid, List *args,
4427 : bool funcvariadic,
4428 : HeapTuple func_tuple,
4429 : eval_const_expressions_context *context)
4430 : {
4431 1219860 : Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
4432 1219860 : bool has_nonconst_input = false;
4433 1219860 : bool has_null_input = false;
4434 : ListCell *arg;
4435 : FuncExpr *newexpr;
4436 :
4437 : /*
4438 : * Can't simplify if it returns a set.
4439 : */
4440 1219860 : if (funcform->proretset)
4441 57928 : return NULL;
4442 :
4443 : /*
4444 : * Can't simplify if it returns RECORD. The immediate problem is that it
4445 : * will be needing an expected tupdesc which we can't supply here.
4446 : *
4447 : * In the case where it has OUT parameters, we could build an expected
4448 : * tupdesc from those, but there may be other gotchas lurking. In
4449 : * particular, if the function were to return NULL, we would produce a
4450 : * null constant with no remaining indication of which concrete record
4451 : * type it is. For now, seems best to leave the function call unreduced.
4452 : */
4453 1161932 : if (funcform->prorettype == RECORDOID)
4454 4548 : return NULL;
4455 :
4456 : /*
4457 : * Check for constant inputs and especially constant-NULL inputs.
4458 : */
4459 3074020 : foreach(arg, args)
4460 : {
4461 1916636 : if (IsA(lfirst(arg), Const))
4462 812112 : has_null_input |= ((Const *) lfirst(arg))->constisnull;
4463 : else
4464 1104524 : has_nonconst_input = true;
4465 : }
4466 :
4467 : /*
4468 : * If the function is strict and has a constant-NULL input, it will never
4469 : * be called at all, so we can replace the call by a NULL constant, even
4470 : * if there are other inputs that aren't constant, and even if the
4471 : * function is not otherwise immutable.
4472 : */
4473 1157384 : if (funcform->proisstrict && has_null_input)
4474 634 : return (Expr *) makeNullConst(result_type, result_typmod,
4475 : result_collid);
4476 :
4477 : /*
4478 : * Otherwise, can simplify only if all inputs are constants. (For a
4479 : * non-strict function, constant NULL inputs are treated the same as
4480 : * constant non-NULL inputs.)
4481 : */
4482 1156750 : if (has_nonconst_input)
4483 829198 : return NULL;
4484 :
4485 : /*
4486 : * Ordinarily we are only allowed to simplify immutable functions. But for
4487 : * purposes of estimation, we consider it okay to simplify functions that
4488 : * are merely stable; the risk that the result might change from planning
4489 : * time to execution time is worth taking in preference to not being able
4490 : * to estimate the value at all.
4491 : */
4492 327552 : if (funcform->provolatile == PROVOLATILE_IMMUTABLE)
4493 : /* okay */ ;
4494 153920 : else if (context->estimate && funcform->provolatile == PROVOLATILE_STABLE)
4495 : /* okay */ ;
4496 : else
4497 152046 : return NULL;
4498 :
4499 : /*
4500 : * OK, looks like we can simplify this operator/function.
4501 : *
4502 : * Build a new FuncExpr node containing the already-simplified arguments.
4503 : */
4504 175506 : newexpr = makeNode(FuncExpr);
4505 175506 : newexpr->funcid = funcid;
4506 175506 : newexpr->funcresulttype = result_type;
4507 175506 : newexpr->funcretset = false;
4508 175506 : newexpr->funcvariadic = funcvariadic;
4509 175506 : newexpr->funcformat = COERCE_EXPLICIT_CALL; /* doesn't matter */
4510 175506 : newexpr->funccollid = result_collid; /* doesn't matter */
4511 175506 : newexpr->inputcollid = input_collid;
4512 175506 : newexpr->args = args;
4513 175506 : newexpr->location = -1;
4514 :
4515 175506 : return evaluate_expr((Expr *) newexpr, result_type, result_typmod,
4516 : result_collid);
4517 : }
4518 :
4519 : /*
4520 : * inline_function: try to expand a function call inline
4521 : *
4522 : * If the function is a sufficiently simple SQL-language function
4523 : * (just "SELECT expression"), then we can inline it and avoid the rather
4524 : * high per-call overhead of SQL functions. Furthermore, this can expose
4525 : * opportunities for constant-folding within the function expression.
4526 : *
4527 : * We have to beware of some special cases however. A directly or
4528 : * indirectly recursive function would cause us to recurse forever,
4529 : * so we keep track of which functions we are already expanding and
4530 : * do not re-expand them. Also, if a parameter is used more than once
4531 : * in the SQL-function body, we require it not to contain any volatile
4532 : * functions (volatiles might deliver inconsistent answers) nor to be
4533 : * unreasonably expensive to evaluate. The expensiveness check not only
4534 : * prevents us from doing multiple evaluations of an expensive parameter
4535 : * at runtime, but is a safety value to limit growth of an expression due
4536 : * to repeated inlining.
4537 : *
4538 : * We must also beware of changing the volatility or strictness status of
4539 : * functions by inlining them.
4540 : *
4541 : * Also, at the moment we can't inline functions returning RECORD. This
4542 : * doesn't work in the general case because it discards information such
4543 : * as OUT-parameter declarations.
4544 : *
4545 : * Also, context-dependent expression nodes in the argument list are trouble.
4546 : *
4547 : * Returns a simplified expression if successful, or NULL if cannot
4548 : * simplify the function.
4549 : */
4550 : static Expr *
4551 1043594 : inline_function(Oid funcid, Oid result_type, Oid result_collid,
4552 : Oid input_collid, List *args,
4553 : bool funcvariadic,
4554 : HeapTuple func_tuple,
4555 : eval_const_expressions_context *context)
4556 : {
4557 1043594 : Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
4558 : char *src;
4559 : Datum tmp;
4560 : bool isNull;
4561 : MemoryContext oldcxt;
4562 : MemoryContext mycxt;
4563 : inline_error_callback_arg callback_arg;
4564 : ErrorContextCallback sqlerrcontext;
4565 : FuncExpr *fexpr;
4566 : SQLFunctionParseInfoPtr pinfo;
4567 : TupleDesc rettupdesc;
4568 : ParseState *pstate;
4569 : List *raw_parsetree_list;
4570 : List *querytree_list;
4571 : Query *querytree;
4572 : Node *newexpr;
4573 : int *usecounts;
4574 : ListCell *arg;
4575 : int i;
4576 :
4577 : /*
4578 : * Forget it if the function is not SQL-language or has other showstopper
4579 : * properties. (The prokind and nargs checks are just paranoia.)
4580 : */
4581 1043594 : if (funcform->prolang != SQLlanguageId ||
4582 32392 : funcform->prokind != PROKIND_FUNCTION ||
4583 32392 : funcform->prosecdef ||
4584 32380 : funcform->proretset ||
4585 30972 : funcform->prorettype == RECORDOID ||
4586 61290 : !heap_attisnull(func_tuple, Anum_pg_proc_proconfig, NULL) ||
4587 30624 : funcform->pronargs != list_length(args))
4588 1012970 : return NULL;
4589 :
4590 : /* Check for recursive function, and give up trying to expand if so */
4591 30624 : if (list_member_oid(context->active_fns, funcid))
4592 8238 : return NULL;
4593 :
4594 : /* Check permission to call function (fail later, if not) */
4595 22386 : if (object_aclcheck(ProcedureRelationId, funcid, GetUserId(), ACL_EXECUTE) != ACLCHECK_OK)
4596 14 : return NULL;
4597 :
4598 : /* Check whether a plugin wants to hook function entry/exit */
4599 22372 : if (FmgrHookIsNeeded(funcid))
4600 0 : return NULL;
4601 :
4602 : /*
4603 : * Make a temporary memory context, so that we don't leak all the stuff
4604 : * that parsing might create.
4605 : */
4606 22372 : mycxt = AllocSetContextCreate(CurrentMemoryContext,
4607 : "inline_function",
4608 : ALLOCSET_DEFAULT_SIZES);
4609 22372 : oldcxt = MemoryContextSwitchTo(mycxt);
4610 :
4611 : /*
4612 : * We need a dummy FuncExpr node containing the already-simplified
4613 : * arguments. (In some cases we don't really need it, but building it is
4614 : * cheap enough that it's not worth contortions to avoid.)
4615 : */
4616 22372 : fexpr = makeNode(FuncExpr);
4617 22372 : fexpr->funcid = funcid;
4618 22372 : fexpr->funcresulttype = result_type;
4619 22372 : fexpr->funcretset = false;
4620 22372 : fexpr->funcvariadic = funcvariadic;
4621 22372 : fexpr->funcformat = COERCE_EXPLICIT_CALL; /* doesn't matter */
4622 22372 : fexpr->funccollid = result_collid; /* doesn't matter */
4623 22372 : fexpr->inputcollid = input_collid;
4624 22372 : fexpr->args = args;
4625 22372 : fexpr->location = -1;
4626 :
4627 : /* Fetch the function body */
4628 22372 : tmp = SysCacheGetAttrNotNull(PROCOID, func_tuple, Anum_pg_proc_prosrc);
4629 22372 : src = TextDatumGetCString(tmp);
4630 :
4631 : /*
4632 : * Setup error traceback support for ereport(). This is so that we can
4633 : * finger the function that bad information came from.
4634 : */
4635 22372 : callback_arg.proname = NameStr(funcform->proname);
4636 22372 : callback_arg.prosrc = src;
4637 :
4638 22372 : sqlerrcontext.callback = sql_inline_error_callback;
4639 22372 : sqlerrcontext.arg = (void *) &callback_arg;
4640 22372 : sqlerrcontext.previous = error_context_stack;
4641 22372 : error_context_stack = &sqlerrcontext;
4642 :
4643 : /* If we have prosqlbody, pay attention to that not prosrc */
4644 22372 : tmp = SysCacheGetAttr(PROCOID,
4645 : func_tuple,
4646 : Anum_pg_proc_prosqlbody,
4647 : &isNull);
4648 22372 : if (!isNull)
4649 : {
4650 : Node *n;
4651 : List *query_list;
4652 :
4653 3094 : n = stringToNode(TextDatumGetCString(tmp));
4654 3094 : if (IsA(n, List))
4655 2298 : query_list = linitial_node(List, castNode(List, n));
4656 : else
4657 796 : query_list = list_make1(n);
4658 3094 : if (list_length(query_list) != 1)
4659 6 : goto fail;
4660 3088 : querytree = linitial(query_list);
4661 :
4662 : /*
4663 : * Because we'll insist below that the querytree have an empty rtable
4664 : * and no sublinks, it cannot have any relation references that need
4665 : * to be locked or rewritten. So we can omit those steps.
4666 : */
4667 : }
4668 : else
4669 : {
4670 : /* Set up to handle parameters while parsing the function body. */
4671 19278 : pinfo = prepare_sql_fn_parse_info(func_tuple,
4672 : (Node *) fexpr,
4673 : input_collid);
4674 :
4675 : /*
4676 : * We just do parsing and parse analysis, not rewriting, because
4677 : * rewriting will not affect table-free-SELECT-only queries, which is
4678 : * all that we care about. Also, we can punt as soon as we detect
4679 : * more than one command in the function body.
4680 : */
4681 19278 : raw_parsetree_list = pg_parse_query(src);
4682 19274 : if (list_length(raw_parsetree_list) != 1)
4683 74 : goto fail;
4684 :
4685 19200 : pstate = make_parsestate(NULL);
4686 19200 : pstate->p_sourcetext = src;
4687 19200 : sql_fn_parser_setup(pstate, pinfo);
4688 :
4689 19200 : querytree = transformTopLevelStmt(pstate, linitial(raw_parsetree_list));
4690 :
4691 19192 : free_parsestate(pstate);
4692 : }
4693 :
4694 : /*
4695 : * The single command must be a simple "SELECT expression".
4696 : *
4697 : * Note: if you change the tests involved in this, see also plpgsql's
4698 : * exec_simple_check_plan(). That generally needs to have the same idea
4699 : * of what's a "simple expression", so that inlining a function that
4700 : * previously wasn't inlined won't change plpgsql's conclusion.
4701 : */
4702 22280 : if (!IsA(querytree, Query) ||
4703 22280 : querytree->commandType != CMD_SELECT ||
4704 22164 : querytree->hasAggs ||
4705 22086 : querytree->hasWindowFuncs ||
4706 22086 : querytree->hasTargetSRFs ||
4707 22086 : querytree->hasSubLinks ||
4708 21454 : querytree->cteList ||
4709 21454 : querytree->rtable ||
4710 19708 : querytree->jointree->fromlist ||
4711 19708 : querytree->jointree->quals ||
4712 19708 : querytree->groupClause ||
4713 19708 : querytree->groupingSets ||
4714 19708 : querytree->havingQual ||
4715 19708 : querytree->windowClause ||
4716 19708 : querytree->distinctClause ||
4717 19708 : querytree->sortClause ||
4718 19708 : querytree->limitOffset ||
4719 19708 : querytree->limitCount ||
4720 39264 : querytree->setOperations ||
4721 19632 : list_length(querytree->targetList) != 1)
4722 2708 : goto fail;
4723 :
4724 : /* If the function result is composite, resolve it */
4725 19572 : (void) get_expr_result_type((Node *) fexpr,
4726 : NULL,
4727 : &rettupdesc);
4728 :
4729 : /*
4730 : * Make sure the function (still) returns what it's declared to. This
4731 : * will raise an error if wrong, but that's okay since the function would
4732 : * fail at runtime anyway. Note that check_sql_fn_retval will also insert
4733 : * a coercion if needed to make the tlist expression match the declared
4734 : * type of the function.
4735 : *
4736 : * Note: we do not try this until we have verified that no rewriting was
4737 : * needed; that's probably not important, but let's be careful.
4738 : */
4739 19572 : querytree_list = list_make1(querytree);
4740 19572 : if (check_sql_fn_retval(list_make1(querytree_list),
4741 : result_type, rettupdesc,
4742 19572 : funcform->prokind,
4743 : false, NULL))
4744 12 : goto fail; /* reject whole-tuple-result cases */
4745 :
4746 : /*
4747 : * Given the tests above, check_sql_fn_retval shouldn't have decided to
4748 : * inject a projection step, but let's just make sure.
4749 : */
4750 19554 : if (querytree != linitial(querytree_list))
4751 0 : goto fail;
4752 :
4753 : /* Now we can grab the tlist expression */
4754 19554 : newexpr = (Node *) ((TargetEntry *) linitial(querytree->targetList))->expr;
4755 :
4756 : /*
4757 : * If the SQL function returns VOID, we can only inline it if it is a
4758 : * SELECT of an expression returning VOID (ie, it's just a redirection to
4759 : * another VOID-returning function). In all non-VOID-returning cases,
4760 : * check_sql_fn_retval should ensure that newexpr returns the function's
4761 : * declared result type, so this test shouldn't fail otherwise; but we may
4762 : * as well cope gracefully if it does.
4763 : */
4764 19554 : if (exprType(newexpr) != result_type)
4765 18 : goto fail;
4766 :
4767 : /*
4768 : * Additional validity checks on the expression. It mustn't be more
4769 : * volatile than the surrounding function (this is to avoid breaking hacks
4770 : * that involve pretending a function is immutable when it really ain't).
4771 : * If the surrounding function is declared strict, then the expression
4772 : * must contain only strict constructs and must use all of the function
4773 : * parameters (this is overkill, but an exact analysis is hard).
4774 : */
4775 20380 : if (funcform->provolatile == PROVOLATILE_IMMUTABLE &&
4776 844 : contain_mutable_functions(newexpr))
4777 12 : goto fail;
4778 20404 : else if (funcform->provolatile == PROVOLATILE_STABLE &&
4779 880 : contain_volatile_functions(newexpr))
4780 0 : goto fail;
4781 :
4782 21226 : if (funcform->proisstrict &&
4783 1702 : contain_nonstrict_functions(newexpr))
4784 172 : goto fail;
4785 :
4786 : /*
4787 : * If any parameter expression contains a context-dependent node, we can't
4788 : * inline, for fear of putting such a node into the wrong context.
4789 : */
4790 19352 : if (contain_context_dependent_node((Node *) args))
4791 6 : goto fail;
4792 :
4793 : /*
4794 : * We may be able to do it; there are still checks on parameter usage to
4795 : * make, but those are most easily done in combination with the actual
4796 : * substitution of the inputs. So start building expression with inputs
4797 : * substituted.
4798 : */
4799 19346 : usecounts = (int *) palloc0(funcform->pronargs * sizeof(int));
4800 19346 : newexpr = substitute_actual_parameters(newexpr, funcform->pronargs,
4801 : args, usecounts);
4802 :
4803 : /* Now check for parameter usage */
4804 19346 : i = 0;
4805 40500 : foreach(arg, args)
4806 : {
4807 21154 : Node *param = lfirst(arg);
4808 :
4809 21154 : if (usecounts[i] == 0)
4810 : {
4811 : /* Param not used at all: uncool if func is strict */
4812 272 : if (funcform->proisstrict)
4813 0 : goto fail;
4814 : }
4815 20882 : else if (usecounts[i] != 1)
4816 : {
4817 : /* Param used multiple times: uncool if expensive or volatile */
4818 : QualCost eval_cost;
4819 :
4820 : /*
4821 : * We define "expensive" as "contains any subplan or more than 10
4822 : * operators". Note that the subplan search has to be done
4823 : * explicitly, since cost_qual_eval() will barf on unplanned
4824 : * subselects.
4825 : */
4826 16454 : if (contain_subplans(param))
4827 0 : goto fail;
4828 16454 : cost_qual_eval(&eval_cost, list_make1(param), NULL);
4829 16454 : if (eval_cost.startup + eval_cost.per_tuple >
4830 16454 : 10 * cpu_operator_cost)
4831 0 : goto fail;
4832 :
4833 : /*
4834 : * Check volatility last since this is more expensive than the
4835 : * above tests
4836 : */
4837 16454 : if (contain_volatile_functions(param))
4838 0 : goto fail;
4839 : }
4840 21154 : i++;
4841 : }
4842 :
4843 : /*
4844 : * Whew --- we can make the substitution. Copy the modified expression
4845 : * out of the temporary memory context, and clean up.
4846 : */
4847 19346 : MemoryContextSwitchTo(oldcxt);
4848 :
4849 19346 : newexpr = copyObject(newexpr);
4850 :
4851 19346 : MemoryContextDelete(mycxt);
4852 :
4853 : /*
4854 : * If the result is of a collatable type, force the result to expose the
4855 : * correct collation. In most cases this does not matter, but it's
4856 : * possible that the function result is used directly as a sort key or in
4857 : * other places where we expect exprCollation() to tell the truth.
4858 : */
4859 19346 : if (OidIsValid(result_collid))
4860 : {
4861 1398 : Oid exprcoll = exprCollation(newexpr);
4862 :
4863 1398 : if (OidIsValid(exprcoll) && exprcoll != result_collid)
4864 : {
4865 36 : CollateExpr *newnode = makeNode(CollateExpr);
4866 :
4867 36 : newnode->arg = (Expr *) newexpr;
4868 36 : newnode->collOid = result_collid;
4869 36 : newnode->location = -1;
4870 :
4871 36 : newexpr = (Node *) newnode;
4872 : }
4873 : }
4874 :
4875 : /*
4876 : * Since there is now no trace of the function in the plan tree, we must
4877 : * explicitly record the plan's dependency on the function.
4878 : */
4879 19346 : if (context->root)
4880 19128 : record_plan_function_dependency(context->root, funcid);
4881 :
4882 : /*
4883 : * Recursively try to simplify the modified expression. Here we must add
4884 : * the current function to the context list of active functions.
4885 : */
4886 19346 : context->active_fns = lappend_oid(context->active_fns, funcid);
4887 19346 : newexpr = eval_const_expressions_mutator(newexpr, context);
4888 19344 : context->active_fns = list_delete_last(context->active_fns);
4889 :
4890 19344 : error_context_stack = sqlerrcontext.previous;
4891 :
4892 19344 : return (Expr *) newexpr;
4893 :
4894 : /* Here if func is not inlinable: release temp memory and return NULL */
4895 3008 : fail:
4896 3008 : MemoryContextSwitchTo(oldcxt);
4897 3008 : MemoryContextDelete(mycxt);
4898 3008 : error_context_stack = sqlerrcontext.previous;
4899 :
4900 3008 : return NULL;
4901 : }
4902 :
4903 : /*
4904 : * Replace Param nodes by appropriate actual parameters
4905 : */
4906 : static Node *
4907 19346 : substitute_actual_parameters(Node *expr, int nargs, List *args,
4908 : int *usecounts)
4909 : {
4910 : substitute_actual_parameters_context context;
4911 :
4912 19346 : context.nargs = nargs;
4913 19346 : context.args = args;
4914 19346 : context.usecounts = usecounts;
4915 :
4916 19346 : return substitute_actual_parameters_mutator(expr, &context);
4917 : }
4918 :
4919 : static Node *
4920 165772 : substitute_actual_parameters_mutator(Node *node,
4921 : substitute_actual_parameters_context *context)
4922 : {
4923 165772 : if (node == NULL)
4924 16782 : return NULL;
4925 148990 : if (IsA(node, Param))
4926 : {
4927 38402 : Param *param = (Param *) node;
4928 :
4929 38402 : if (param->paramkind != PARAM_EXTERN)
4930 0 : elog(ERROR, "unexpected paramkind: %d", (int) param->paramkind);
4931 38402 : if (param->paramid <= 0 || param->paramid > context->nargs)
4932 0 : elog(ERROR, "invalid paramid: %d", param->paramid);
4933 :
4934 : /* Count usage of parameter */
4935 38402 : context->usecounts[param->paramid - 1]++;
4936 :
4937 : /* Select the appropriate actual arg and replace the Param with it */
4938 : /* We don't need to copy at this time (it'll get done later) */
4939 38402 : return list_nth(context->args, param->paramid - 1);
4940 : }
4941 110588 : return expression_tree_mutator(node, substitute_actual_parameters_mutator,
4942 : (void *) context);
4943 : }
4944 :
4945 : /*
4946 : * error context callback to let us supply a call-stack traceback
4947 : */
4948 : static void
4949 26 : sql_inline_error_callback(void *arg)
4950 : {
4951 26 : inline_error_callback_arg *callback_arg = (inline_error_callback_arg *) arg;
4952 : int syntaxerrposition;
4953 :
4954 : /* If it's a syntax error, convert to internal syntax error report */
4955 26 : syntaxerrposition = geterrposition();
4956 26 : if (syntaxerrposition > 0)
4957 : {
4958 6 : errposition(0);
4959 6 : internalerrposition(syntaxerrposition);
4960 6 : internalerrquery(callback_arg->prosrc);
4961 : }
4962 :
4963 26 : errcontext("SQL function \"%s\" during inlining", callback_arg->proname);
4964 26 : }
4965 :
4966 : /*
4967 : * evaluate_expr: pre-evaluate a constant expression
4968 : *
4969 : * We use the executor's routine ExecEvalExpr() to avoid duplication of
4970 : * code and ensure we get the same result as the executor would get.
4971 : */
4972 : Expr *
4973 207882 : evaluate_expr(Expr *expr, Oid result_type, int32 result_typmod,
4974 : Oid result_collation)
4975 : {
4976 : EState *estate;
4977 : ExprState *exprstate;
4978 : MemoryContext oldcontext;
4979 : Datum const_val;
4980 : bool const_is_null;
4981 : int16 resultTypLen;
4982 : bool resultTypByVal;
4983 :
4984 : /*
4985 : * To use the executor, we need an EState.
4986 : */
4987 207882 : estate = CreateExecutorState();
4988 :
4989 : /* We can use the estate's working context to avoid memory leaks. */
4990 207882 : oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
4991 :
4992 : /* Make sure any opfuncids are filled in. */
4993 207882 : fix_opfuncids((Node *) expr);
4994 :
4995 : /*
4996 : * Prepare expr for execution. (Note: we can't use ExecPrepareExpr
4997 : * because it'd result in recursively invoking eval_const_expressions.)
4998 : */
4999 207882 : exprstate = ExecInitExpr(expr, NULL);
5000 :
5001 : /*
5002 : * And evaluate it.
5003 : *
5004 : * It is OK to use a default econtext because none of the ExecEvalExpr()
5005 : * code used in this situation will use econtext. That might seem
5006 : * fortuitous, but it's not so unreasonable --- a constant expression does
5007 : * not depend on context, by definition, n'est ce pas?
5008 : */
5009 207864 : const_val = ExecEvalExprSwitchContext(exprstate,
5010 207864 : GetPerTupleExprContext(estate),
5011 : &const_is_null);
5012 :
5013 : /* Get info needed about result datatype */
5014 204250 : get_typlenbyval(result_type, &resultTypLen, &resultTypByVal);
5015 :
5016 : /* Get back to outer memory context */
5017 204250 : MemoryContextSwitchTo(oldcontext);
5018 :
5019 : /*
5020 : * Must copy result out of sub-context used by expression eval.
5021 : *
5022 : * Also, if it's varlena, forcibly detoast it. This protects us against
5023 : * storing TOAST pointers into plans that might outlive the referenced
5024 : * data. (makeConst would handle detoasting anyway, but it's worth a few
5025 : * extra lines here so that we can do the copy and detoast in one step.)
5026 : */
5027 204250 : if (!const_is_null)
5028 : {
5029 202842 : if (resultTypLen == -1)
5030 78614 : const_val = PointerGetDatum(PG_DETOAST_DATUM_COPY(const_val));
5031 : else
5032 124228 : const_val = datumCopy(const_val, resultTypByVal, resultTypLen);
5033 : }
5034 :
5035 : /* Release all the junk we just created */
5036 204250 : FreeExecutorState(estate);
5037 :
5038 : /*
5039 : * Make the constant result node.
5040 : */
5041 204250 : return (Expr *) makeConst(result_type, result_typmod, result_collation,
5042 : resultTypLen,
5043 : const_val, const_is_null,
5044 : resultTypByVal);
5045 : }
5046 :
5047 :
5048 : /*
5049 : * inline_set_returning_function
5050 : * Attempt to "inline" a set-returning function in the FROM clause.
5051 : *
5052 : * "rte" is an RTE_FUNCTION rangetable entry. If it represents a call of a
5053 : * set-returning SQL function that can safely be inlined, expand the function
5054 : * and return the substitute Query structure. Otherwise, return NULL.
5055 : *
5056 : * We assume that the RTE's expression has already been put through
5057 : * eval_const_expressions(), which among other things will take care of
5058 : * default arguments and named-argument notation.
5059 : *
5060 : * This has a good deal of similarity to inline_function(), but that's
5061 : * for the non-set-returning case, and there are enough differences to
5062 : * justify separate functions.
5063 : */
5064 : Query *
5065 44404 : inline_set_returning_function(PlannerInfo *root, RangeTblEntry *rte)
5066 : {
5067 : RangeTblFunction *rtfunc;
5068 : FuncExpr *fexpr;
5069 : Oid func_oid;
5070 : HeapTuple func_tuple;
5071 : Form_pg_proc funcform;
5072 : char *src;
5073 : Datum tmp;
5074 : bool isNull;
5075 : MemoryContext oldcxt;
5076 : MemoryContext mycxt;
5077 : inline_error_callback_arg callback_arg;
5078 : ErrorContextCallback sqlerrcontext;
5079 : SQLFunctionParseInfoPtr pinfo;
5080 : TypeFuncClass functypclass;
5081 : TupleDesc rettupdesc;
5082 : List *raw_parsetree_list;
5083 : List *querytree_list;
5084 : Query *querytree;
5085 :
5086 : Assert(rte->rtekind == RTE_FUNCTION);
5087 :
5088 : /*
5089 : * It doesn't make a lot of sense for a SQL SRF to refer to itself in its
5090 : * own FROM clause, since that must cause infinite recursion at runtime.
5091 : * It will cause this code to recurse too, so check for stack overflow.
5092 : * (There's no need to do more.)
5093 : */
5094 44404 : check_stack_depth();
5095 :
5096 : /* Fail if the RTE has ORDINALITY - we don't implement that here. */
5097 44404 : if (rte->funcordinality)
5098 698 : return NULL;
5099 :
5100 : /* Fail if RTE isn't a single, simple FuncExpr */
5101 43706 : if (list_length(rte->functions) != 1)
5102 72 : return NULL;
5103 43634 : rtfunc = (RangeTblFunction *) linitial(rte->functions);
5104 :
5105 43634 : if (!IsA(rtfunc->funcexpr, FuncExpr))
5106 414 : return NULL;
5107 43220 : fexpr = (FuncExpr *) rtfunc->funcexpr;
5108 :
5109 43220 : func_oid = fexpr->funcid;
5110 :
5111 : /*
5112 : * The function must be declared to return a set, else inlining would
5113 : * change the results if the contained SELECT didn't return exactly one
5114 : * row.
5115 : */
5116 43220 : if (!fexpr->funcretset)
5117 4516 : return NULL;
5118 :
5119 : /*
5120 : * Refuse to inline if the arguments contain any volatile functions or
5121 : * sub-selects. Volatile functions are rejected because inlining may
5122 : * result in the arguments being evaluated multiple times, risking a
5123 : * change in behavior. Sub-selects are rejected partly for implementation
5124 : * reasons (pushing them down another level might change their behavior)
5125 : * and partly because they're likely to be expensive and so multiple
5126 : * evaluation would be bad.
5127 : */
5128 77272 : if (contain_volatile_functions((Node *) fexpr->args) ||
5129 38568 : contain_subplans((Node *) fexpr->args))
5130 374 : return NULL;
5131 :
5132 : /* Check permission to call function (fail later, if not) */
5133 38330 : if (object_aclcheck(ProcedureRelationId, func_oid, GetUserId(), ACL_EXECUTE) != ACLCHECK_OK)
5134 8 : return NULL;
5135 :
5136 : /* Check whether a plugin wants to hook function entry/exit */
5137 38322 : if (FmgrHookIsNeeded(func_oid))
5138 0 : return NULL;
5139 :
5140 : /*
5141 : * OK, let's take a look at the function's pg_proc entry.
5142 : */
5143 38322 : func_tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(func_oid));
5144 38322 : if (!HeapTupleIsValid(func_tuple))
5145 0 : elog(ERROR, "cache lookup failed for function %u", func_oid);
5146 38322 : funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
5147 :
5148 : /*
5149 : * Forget it if the function is not SQL-language or has other showstopper
5150 : * properties. In particular it mustn't be declared STRICT, since we
5151 : * couldn't enforce that. It also mustn't be VOLATILE, because that is
5152 : * supposed to cause it to be executed with its own snapshot, rather than
5153 : * sharing the snapshot of the calling query. We also disallow returning
5154 : * SETOF VOID, because inlining would result in exposing the actual result
5155 : * of the function's last SELECT, which should not happen in that case.
5156 : * (Rechecking prokind, proretset, and pronargs is just paranoia.)
5157 : */
5158 38322 : if (funcform->prolang != SQLlanguageId ||
5159 636 : funcform->prokind != PROKIND_FUNCTION ||
5160 636 : funcform->proisstrict ||
5161 576 : funcform->provolatile == PROVOLATILE_VOLATILE ||
5162 222 : funcform->prorettype == VOIDOID ||
5163 216 : funcform->prosecdef ||
5164 216 : !funcform->proretset ||
5165 216 : list_length(fexpr->args) != funcform->pronargs ||
5166 216 : !heap_attisnull(func_tuple, Anum_pg_proc_proconfig, NULL))
5167 : {
5168 38106 : ReleaseSysCache(func_tuple);
5169 38106 : return NULL;
5170 : }
5171 :
5172 : /*
5173 : * Make a temporary memory context, so that we don't leak all the stuff
5174 : * that parsing might create.
5175 : */
5176 216 : mycxt = AllocSetContextCreate(CurrentMemoryContext,
5177 : "inline_set_returning_function",
5178 : ALLOCSET_DEFAULT_SIZES);
5179 216 : oldcxt = MemoryContextSwitchTo(mycxt);
5180 :
5181 : /* Fetch the function body */
5182 216 : tmp = SysCacheGetAttrNotNull(PROCOID, func_tuple, Anum_pg_proc_prosrc);
5183 216 : src = TextDatumGetCString(tmp);
5184 :
5185 : /*
5186 : * Setup error traceback support for ereport(). This is so that we can
5187 : * finger the function that bad information came from.
5188 : */
5189 216 : callback_arg.proname = NameStr(funcform->proname);
5190 216 : callback_arg.prosrc = src;
5191 :
5192 216 : sqlerrcontext.callback = sql_inline_error_callback;
5193 216 : sqlerrcontext.arg = (void *) &callback_arg;
5194 216 : sqlerrcontext.previous = error_context_stack;
5195 216 : error_context_stack = &sqlerrcontext;
5196 :
5197 : /* If we have prosqlbody, pay attention to that not prosrc */
5198 216 : tmp = SysCacheGetAttr(PROCOID,
5199 : func_tuple,
5200 : Anum_pg_proc_prosqlbody,
5201 : &isNull);
5202 216 : if (!isNull)
5203 : {
5204 : Node *n;
5205 :
5206 12 : n = stringToNode(TextDatumGetCString(tmp));
5207 12 : if (IsA(n, List))
5208 12 : querytree_list = linitial_node(List, castNode(List, n));
5209 : else
5210 0 : querytree_list = list_make1(n);
5211 12 : if (list_length(querytree_list) != 1)
5212 0 : goto fail;
5213 12 : querytree = linitial(querytree_list);
5214 :
5215 : /* Acquire necessary locks, then apply rewriter. */
5216 12 : AcquireRewriteLocks(querytree, true, false);
5217 12 : querytree_list = pg_rewrite_query(querytree);
5218 12 : if (list_length(querytree_list) != 1)
5219 0 : goto fail;
5220 12 : querytree = linitial(querytree_list);
5221 : }
5222 : else
5223 : {
5224 : /*
5225 : * Set up to handle parameters while parsing the function body. We
5226 : * can use the FuncExpr just created as the input for
5227 : * prepare_sql_fn_parse_info.
5228 : */
5229 204 : pinfo = prepare_sql_fn_parse_info(func_tuple,
5230 : (Node *) fexpr,
5231 : fexpr->inputcollid);
5232 :
5233 : /*
5234 : * Parse, analyze, and rewrite (unlike inline_function(), we can't
5235 : * skip rewriting here). We can fail as soon as we find more than one
5236 : * query, though.
5237 : */
5238 204 : raw_parsetree_list = pg_parse_query(src);
5239 204 : if (list_length(raw_parsetree_list) != 1)
5240 0 : goto fail;
5241 :
5242 204 : querytree_list = pg_analyze_and_rewrite_withcb(linitial(raw_parsetree_list),
5243 : src,
5244 : (ParserSetupHook) sql_fn_parser_setup,
5245 : pinfo, NULL);
5246 204 : if (list_length(querytree_list) != 1)
5247 0 : goto fail;
5248 204 : querytree = linitial(querytree_list);
5249 : }
5250 :
5251 : /*
5252 : * Also resolve the actual function result tupdesc, if composite. If we
5253 : * have a coldeflist, believe that; otherwise use get_expr_result_type.
5254 : * (This logic should match ExecInitFunctionScan.)
5255 : */
5256 216 : if (rtfunc->funccolnames != NIL)
5257 : {
5258 24 : functypclass = TYPEFUNC_RECORD;
5259 24 : rettupdesc = BuildDescFromLists(rtfunc->funccolnames,
5260 24 : rtfunc->funccoltypes,
5261 24 : rtfunc->funccoltypmods,
5262 24 : rtfunc->funccolcollations);
5263 : }
5264 : else
5265 192 : functypclass = get_expr_result_type((Node *) fexpr, NULL, &rettupdesc);
5266 :
5267 : /*
5268 : * The single command must be a plain SELECT.
5269 : */
5270 216 : if (!IsA(querytree, Query) ||
5271 216 : querytree->commandType != CMD_SELECT)
5272 0 : goto fail;
5273 :
5274 : /*
5275 : * Make sure the function (still) returns what it's declared to. This
5276 : * will raise an error if wrong, but that's okay since the function would
5277 : * fail at runtime anyway. Note that check_sql_fn_retval will also insert
5278 : * coercions if needed to make the tlist expression(s) match the declared
5279 : * type of the function. We also ask it to insert dummy NULL columns for
5280 : * any dropped columns in rettupdesc, so that the elements of the modified
5281 : * tlist match up to the attribute numbers.
5282 : *
5283 : * If the function returns a composite type, don't inline unless the check
5284 : * shows it's returning a whole tuple result; otherwise what it's
5285 : * returning is a single composite column which is not what we need.
5286 : */
5287 216 : if (!check_sql_fn_retval(list_make1(querytree_list),
5288 : fexpr->funcresulttype, rettupdesc,
5289 216 : funcform->prokind,
5290 90 : true, NULL) &&
5291 90 : (functypclass == TYPEFUNC_COMPOSITE ||
5292 90 : functypclass == TYPEFUNC_COMPOSITE_DOMAIN ||
5293 : functypclass == TYPEFUNC_RECORD))
5294 0 : goto fail; /* reject not-whole-tuple-result cases */
5295 :
5296 : /*
5297 : * check_sql_fn_retval might've inserted a projection step, but that's
5298 : * fine; just make sure we use the upper Query.
5299 : */
5300 210 : querytree = linitial_node(Query, querytree_list);
5301 :
5302 : /*
5303 : * Looks good --- substitute parameters into the query.
5304 : */
5305 210 : querytree = substitute_actual_srf_parameters(querytree,
5306 210 : funcform->pronargs,
5307 : fexpr->args);
5308 :
5309 : /*
5310 : * Copy the modified query out of the temporary memory context, and clean
5311 : * up.
5312 : */
5313 210 : MemoryContextSwitchTo(oldcxt);
5314 :
5315 210 : querytree = copyObject(querytree);
5316 :
5317 210 : MemoryContextDelete(mycxt);
5318 210 : error_context_stack = sqlerrcontext.previous;
5319 210 : ReleaseSysCache(func_tuple);
5320 :
5321 : /*
5322 : * We don't have to fix collations here because the upper query is already
5323 : * parsed, ie, the collations in the RTE are what count.
5324 : */
5325 :
5326 : /*
5327 : * Since there is now no trace of the function in the plan tree, we must
5328 : * explicitly record the plan's dependency on the function.
5329 : */
5330 210 : record_plan_function_dependency(root, func_oid);
5331 :
5332 : /*
5333 : * We must also notice if the inserted query adds a dependency on the
5334 : * calling role due to RLS quals.
5335 : */
5336 210 : if (querytree->hasRowSecurity)
5337 72 : root->glob->dependsOnRole = true;
5338 :
5339 210 : return querytree;
5340 :
5341 : /* Here if func is not inlinable: release temp memory and return NULL */
5342 0 : fail:
5343 0 : MemoryContextSwitchTo(oldcxt);
5344 0 : MemoryContextDelete(mycxt);
5345 0 : error_context_stack = sqlerrcontext.previous;
5346 0 : ReleaseSysCache(func_tuple);
5347 :
5348 0 : return NULL;
5349 : }
5350 :
5351 : /*
5352 : * Replace Param nodes by appropriate actual parameters
5353 : *
5354 : * This is just enough different from substitute_actual_parameters()
5355 : * that it needs its own code.
5356 : */
5357 : static Query *
5358 210 : substitute_actual_srf_parameters(Query *expr, int nargs, List *args)
5359 : {
5360 : substitute_actual_srf_parameters_context context;
5361 :
5362 210 : context.nargs = nargs;
5363 210 : context.args = args;
5364 210 : context.sublevels_up = 1;
5365 :
5366 210 : return query_tree_mutator(expr,
5367 : substitute_actual_srf_parameters_mutator,
5368 : &context,
5369 : 0);
5370 : }
5371 :
5372 : static Node *
5373 8022 : substitute_actual_srf_parameters_mutator(Node *node,
5374 : substitute_actual_srf_parameters_context *context)
5375 : {
5376 : Node *result;
5377 :
5378 8022 : if (node == NULL)
5379 4536 : return NULL;
5380 3486 : if (IsA(node, Query))
5381 : {
5382 150 : context->sublevels_up++;
5383 150 : result = (Node *) query_tree_mutator((Query *) node,
5384 : substitute_actual_srf_parameters_mutator,
5385 : (void *) context,
5386 : 0);
5387 150 : context->sublevels_up--;
5388 150 : return result;
5389 : }
5390 3336 : if (IsA(node, Param))
5391 : {
5392 102 : Param *param = (Param *) node;
5393 :
5394 102 : if (param->paramkind == PARAM_EXTERN)
5395 : {
5396 102 : if (param->paramid <= 0 || param->paramid > context->nargs)
5397 0 : elog(ERROR, "invalid paramid: %d", param->paramid);
5398 :
5399 : /*
5400 : * Since the parameter is being inserted into a subquery, we must
5401 : * adjust levels.
5402 : */
5403 102 : result = copyObject(list_nth(context->args, param->paramid - 1));
5404 102 : IncrementVarSublevelsUp(result, context->sublevels_up, 0);
5405 102 : return result;
5406 : }
5407 : }
5408 3234 : return expression_tree_mutator(node,
5409 : substitute_actual_srf_parameters_mutator,
5410 : (void *) context);
5411 : }
5412 :
5413 : /*
5414 : * pull_paramids
5415 : * Returns a Bitmapset containing the paramids of all Params in 'expr'.
5416 : */
5417 : Bitmapset *
5418 1372 : pull_paramids(Expr *expr)
5419 : {
5420 1372 : Bitmapset *result = NULL;
5421 :
5422 1372 : (void) pull_paramids_walker((Node *) expr, &result);
5423 :
5424 1372 : return result;
5425 : }
5426 :
5427 : static bool
5428 3020 : pull_paramids_walker(Node *node, Bitmapset **context)
5429 : {
5430 3020 : if (node == NULL)
5431 18 : return false;
5432 3002 : if (IsA(node, Param))
5433 : {
5434 1414 : Param *param = (Param *) node;
5435 :
5436 1414 : *context = bms_add_member(*context, param->paramid);
5437 1414 : return false;
5438 : }
5439 1588 : return expression_tree_walker(node, pull_paramids_walker,
5440 : (void *) context);
5441 : }
|
