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 9642 : contain_agg_clause(Node *clause)
178 : {
179 9642 : return contain_agg_clause_walker(clause, NULL);
180 : }
181 :
182 : static bool
183 11366 : contain_agg_clause_walker(Node *node, void *context)
184 : {
185 11366 : if (node == NULL)
186 18 : return false;
187 11348 : if (IsA(node, Aggref))
188 : {
189 : Assert(((Aggref *) node)->agglevelsup == 0);
190 1120 : return true; /* abort the tree traversal and return true */
191 : }
192 10228 : if (IsA(node, GroupingFunc))
193 : {
194 : Assert(((GroupingFunc *) node)->agglevelsup == 0);
195 12 : return true; /* abort the tree traversal and return true */
196 : }
197 : Assert(!IsA(node, SubLink));
198 10216 : 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 8368 : contain_window_function(Node *clause)
215 : {
216 8368 : 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 2300 : find_window_functions(Node *clause, Index maxWinRef)
228 : {
229 2300 : WindowFuncLists *lists = palloc(sizeof(WindowFuncLists));
230 :
231 2300 : lists->numWindowFuncs = 0;
232 2300 : lists->maxWinRef = maxWinRef;
233 2300 : lists->windowFuncs = (List **) palloc0((maxWinRef + 1) * sizeof(List *));
234 2300 : (void) find_window_functions_walker(clause, lists);
235 2300 : return lists;
236 : }
237 :
238 : static bool
239 20514 : find_window_functions_walker(Node *node, WindowFuncLists *lists)
240 : {
241 20514 : if (node == NULL)
242 226 : return false;
243 20288 : if (IsA(node, WindowFunc))
244 : {
245 3122 : WindowFunc *wfunc = (WindowFunc *) node;
246 :
247 : /* winref is unsigned, so one-sided test is OK */
248 3122 : 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 3122 : if (!list_member(lists->windowFuncs[wfunc->winref], wfunc))
253 : {
254 6220 : lists->windowFuncs[wfunc->winref] =
255 3110 : lappend(lists->windowFuncs[wfunc->winref], wfunc);
256 3110 : 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 3122 : return false;
266 : }
267 : Assert(!IsA(node, SubLink));
268 17166 : 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 334788 : expression_returns_set_rows(PlannerInfo *root, Node *clause)
290 : {
291 334788 : if (clause == NULL)
292 0 : return 1.0;
293 334788 : if (IsA(clause, FuncExpr))
294 : {
295 49378 : FuncExpr *expr = (FuncExpr *) clause;
296 :
297 49378 : if (expr->funcretset)
298 44350 : return clamp_row_est(get_function_rows(root, expr->funcid, clause));
299 : }
300 290438 : if (IsA(clause, OpExpr))
301 : {
302 3190 : OpExpr *expr = (OpExpr *) clause;
303 :
304 3190 : 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 290432 : 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 55718 : contain_subplans(Node *clause)
331 : {
332 55718 : return contain_subplans_walker(clause, NULL);
333 : }
334 :
335 : static bool
336 170478 : contain_subplans_walker(Node *node, void *context)
337 : {
338 170478 : if (node == NULL)
339 4980 : return false;
340 165498 : if (IsA(node, SubPlan) ||
341 165414 : IsA(node, AlternativeSubPlan) ||
342 165414 : IsA(node, SubLink))
343 328 : return true; /* abort the tree traversal and return true */
344 165170 : 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 157570 : contain_mutable_functions(Node *clause)
371 : {
372 157570 : return contain_mutable_functions_walker(clause, NULL);
373 : }
374 :
375 : static bool
376 114754 : contain_mutable_functions_checker(Oid func_id, void *context)
377 : {
378 114754 : return (func_volatile(func_id) != PROVOLATILE_IMMUTABLE);
379 : }
380 :
381 : static bool
382 403524 : contain_mutable_functions_walker(Node *node, void *context)
383 : {
384 403524 : if (node == NULL)
385 2410 : return false;
386 : /* Check for mutable functions in node itself */
387 401114 : if (check_functions_in_node(node, contain_mutable_functions_checker,
388 : context))
389 8818 : return true;
390 :
391 392296 : 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 392296 : 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 392134 : if (IsA(node, SQLValueFunction))
438 : {
439 : /* all variants of SQLValueFunction are stable */
440 446 : return true;
441 : }
442 :
443 391688 : 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 391688 : 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 391688 : 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 2244 : contain_mutable_functions_after_planning(Expr *expr)
491 : {
492 : /* We assume here that expression_planner() won't scribble on its input */
493 2244 : expr = expression_planner(expr);
494 :
495 : /* Now we can search for non-immutable functions */
496 2244 : 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 2699150 : contain_volatile_functions(Node *clause)
539 : {
540 2699150 : return contain_volatile_functions_walker(clause, NULL);
541 : }
542 :
543 : static bool
544 676736 : contain_volatile_functions_checker(Oid func_id, void *context)
545 : {
546 676736 : return (func_volatile(func_id) == PROVOLATILE_VOLATILE);
547 : }
548 :
549 : static bool
550 5889096 : contain_volatile_functions_walker(Node *node, void *context)
551 : {
552 5889096 : if (node == NULL)
553 177234 : return false;
554 : /* Check for volatile functions in node itself */
555 5711862 : if (check_functions_in_node(node, contain_volatile_functions_checker,
556 : context))
557 1688 : return true;
558 :
559 5710174 : if (IsA(node, NextValueExpr))
560 : {
561 : /* NextValueExpr is volatile */
562 0 : return true;
563 : }
564 :
565 5710174 : if (IsA(node, RestrictInfo))
566 : {
567 1083424 : 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 1083424 : if (rinfo->has_volatile == VOLATILITY_NOVOLATILE)
576 681968 : return false;
577 401456 : else if (rinfo->has_volatile == VOLATILITY_VOLATILE)
578 8 : return true;
579 : else
580 : {
581 : bool hasvolatile;
582 :
583 401448 : hasvolatile = contain_volatile_functions_walker((Node *) rinfo->clause,
584 : context);
585 401448 : if (hasvolatile)
586 64 : rinfo->has_volatile = VOLATILITY_VOLATILE;
587 : else
588 401384 : rinfo->has_volatile = VOLATILITY_NOVOLATILE;
589 :
590 401448 : return hasvolatile;
591 : }
592 : }
593 :
594 4626750 : if (IsA(node, PathTarget))
595 : {
596 325658 : PathTarget *target = (PathTarget *) node;
597 :
598 : /*
599 : * We also do caching for PathTarget the same as we do above for
600 : * RestrictInfos.
601 : */
602 325658 : if (target->has_volatile_expr == VOLATILITY_NOVOLATILE)
603 276542 : return false;
604 49116 : else if (target->has_volatile_expr == VOLATILITY_VOLATILE)
605 0 : return true;
606 : else
607 : {
608 : bool hasvolatile;
609 :
610 49116 : hasvolatile = contain_volatile_functions_walker((Node *) target->exprs,
611 : context);
612 :
613 49116 : if (hasvolatile)
614 0 : target->has_volatile_expr = VOLATILITY_VOLATILE;
615 : else
616 49116 : target->has_volatile_expr = VOLATILITY_NOVOLATILE;
617 :
618 49116 : 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 4301092 : if (IsA(node, Query))
630 : {
631 : /* Recurse into subselects */
632 5972 : return query_tree_walker((Query *) node,
633 : contain_volatile_functions_walker,
634 : context, 0);
635 : }
636 4295120 : 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
659 556 : contain_volatile_functions_after_planning(Expr *expr)
660 : {
661 : /* We assume here that expression_planner() won't scribble on its input */
662 556 : expr = expression_planner(expr);
663 :
664 : /* Now we can search for volatile functions */
665 556 : 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 323524 : max_parallel_hazard(Query *parse)
735 : {
736 : max_parallel_hazard_context context;
737 :
738 323524 : context.max_hazard = PROPARALLEL_SAFE;
739 323524 : context.max_interesting = PROPARALLEL_UNSAFE;
740 323524 : context.safe_param_ids = NIL;
741 323524 : (void) max_parallel_hazard_walker((Node *) parse, &context);
742 323524 : 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 1987108 : 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 1987108 : if (root->glob->maxParallelHazard == PROPARALLEL_SAFE &&
766 1215912 : root->glob->paramExecTypes == NIL)
767 1185406 : return true;
768 : /* Else use max_parallel_hazard's search logic, but stop on RESTRICTED */
769 801702 : context.max_hazard = PROPARALLEL_SAFE;
770 801702 : context.max_interesting = PROPARALLEL_RESTRICTED;
771 801702 : 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 1911690 : for (proot = root; proot != NULL; proot = proot->parent_root)
779 : {
780 1168318 : foreach(l, proot->init_plans)
781 : {
782 58330 : SubPlan *initsubplan = (SubPlan *) lfirst(l);
783 :
784 58330 : context.safe_param_ids = list_concat(context.safe_param_ids,
785 58330 : initsubplan->setParam);
786 : }
787 : }
788 :
789 801702 : return !max_parallel_hazard_walker(node, &context);
790 : }
791 :
792 : /* core logic for all parallel-hazard checks */
793 : static bool
794 1366066 : max_parallel_hazard_test(char proparallel, max_parallel_hazard_context *context)
795 : {
796 1366066 : switch (proparallel)
797 : {
798 1113180 : case PROPARALLEL_SAFE:
799 : /* nothing to see here, move along */
800 1113180 : break;
801 168052 : case PROPARALLEL_RESTRICTED:
802 : /* increase max_hazard to RESTRICTED */
803 : Assert(context->max_hazard != PROPARALLEL_UNSAFE);
804 168052 : context->max_hazard = proparallel;
805 : /* done if we are not expecting any unsafe functions */
806 168052 : if (context->max_interesting == proparallel)
807 89138 : return true;
808 78914 : break;
809 84834 : case PROPARALLEL_UNSAFE:
810 84834 : context->max_hazard = proparallel;
811 : /* we're always done at the first unsafe construct */
812 84834 : return true;
813 0 : default:
814 0 : elog(ERROR, "unrecognized proparallel value \"%c\"", proparallel);
815 : break;
816 : }
817 1192094 : return false;
818 : }
819 :
820 : /* check_functions_in_node callback */
821 : static bool
822 1253048 : max_parallel_hazard_checker(Oid func_id, void *context)
823 : {
824 1253048 : return max_parallel_hazard_test(func_parallel(func_id),
825 : (max_parallel_hazard_context *) context);
826 : }
827 :
828 : static bool
829 17743256 : max_parallel_hazard_walker(Node *node, max_parallel_hazard_context *context)
830 : {
831 17743256 : if (node == NULL)
832 4796108 : return false;
833 :
834 : /* Check for hazardous functions in node itself */
835 12947148 : if (check_functions_in_node(node, max_parallel_hazard_checker,
836 : context))
837 109750 : 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 12837398 : if (IsA(node, CoerceToDomain))
851 : {
852 19052 : if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
853 5714 : return true;
854 : }
855 :
856 12818346 : else if (IsA(node, NextValueExpr))
857 : {
858 446 : if (max_parallel_hazard_test(PROPARALLEL_UNSAFE, context))
859 446 : 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 12817900 : else if (IsA(node, WindowFunc))
871 : {
872 5304 : if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
873 2356 : return true;
874 : }
875 :
876 : /*
877 : * As a notational convenience for callers, look through RestrictInfo.
878 : */
879 12812596 : else if (IsA(node, RestrictInfo))
880 : {
881 209138 : RestrictInfo *rinfo = (RestrictInfo *) node;
882 :
883 209138 : 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 12603458 : else if (IsA(node, SubLink))
891 : {
892 30810 : 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 12572648 : else if (IsA(node, SubPlan))
903 : {
904 25834 : SubPlan *subplan = (SubPlan *) node;
905 : List *save_safe_param_ids;
906 :
907 51362 : if (!subplan->parallel_safe &&
908 25528 : max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
909 25528 : 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 12546814 : else if (IsA(node, Param))
932 : {
933 183874 : Param *param = (Param *) node;
934 :
935 183874 : if (param->paramkind == PARAM_EXTERN)
936 142626 : return false;
937 :
938 41248 : if (param->paramkind != PARAM_EXEC ||
939 39482 : !list_member_int(context->safe_param_ids, param->paramid))
940 : {
941 31878 : if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
942 30178 : return true;
943 : }
944 11070 : 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 12362940 : else if (IsA(node, Query))
953 : {
954 394782 : Query *query = (Query *) node;
955 :
956 : /* SELECT FOR UPDATE/SHARE must be treated as unsafe */
957 394782 : if (query->rowMarks != NULL)
958 : {
959 1732 : context->max_hazard = PROPARALLEL_UNSAFE;
960 1732 : return true;
961 : }
962 :
963 : /* Recurse into subselects */
964 393050 : return query_tree_walker(query,
965 : max_parallel_hazard_walker,
966 : context, 0);
967 : }
968 :
969 : /* Recurse to check arguments */
970 12015254 : 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 1636 : contain_nonstrict_functions(Node *clause)
994 : {
995 1636 : return contain_nonstrict_functions_walker(clause, NULL);
996 : }
997 :
998 : static bool
999 2050 : contain_nonstrict_functions_checker(Oid func_id, void *context)
1000 : {
1001 2050 : return !func_strict(func_id);
1002 : }
1003 :
1004 : static bool
1005 6562 : contain_nonstrict_functions_walker(Node *node, void *context)
1006 : {
1007 6562 : if (node == NULL)
1008 0 : return false;
1009 6562 : if (IsA(node, Aggref))
1010 : {
1011 : /* an aggregate could return non-null with null input */
1012 0 : return true;
1013 : }
1014 6562 : 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 6562 : if (IsA(node, WindowFunc))
1023 : {
1024 : /* a window function could return non-null with null input */
1025 0 : return true;
1026 : }
1027 6562 : 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 6562 : if (IsA(node, DistinctExpr))
1042 : {
1043 : /* IS DISTINCT FROM is inherently non-strict */
1044 0 : return true;
1045 : }
1046 6562 : if (IsA(node, NullIfExpr))
1047 : {
1048 : /* NULLIF is inherently non-strict */
1049 0 : return true;
1050 : }
1051 6562 : if (IsA(node, BoolExpr))
1052 : {
1053 0 : BoolExpr *expr = (BoolExpr *) node;
1054 :
1055 0 : switch (expr->boolop)
1056 : {
1057 0 : case AND_EXPR:
1058 : case OR_EXPR:
1059 : /* AND, OR are inherently non-strict */
1060 0 : return true;
1061 0 : default:
1062 0 : break;
1063 : }
1064 6562 : }
1065 6562 : if (IsA(node, SubLink))
1066 : {
1067 : /* In some cases a sublink might be strict, but in general not */
1068 0 : return true;
1069 : }
1070 6562 : if (IsA(node, SubPlan))
1071 0 : return true;
1072 6562 : if (IsA(node, AlternativeSubPlan))
1073 0 : return true;
1074 6562 : if (IsA(node, FieldStore))
1075 0 : return true;
1076 6562 : 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 966 : return contain_nonstrict_functions_walker((Node *) ((CoerceViaIO *) node)->arg,
1084 : context);
1085 : }
1086 5596 : 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 5596 : if (IsA(node, CaseExpr))
1097 172 : return true;
1098 5424 : if (IsA(node, ArrayExpr))
1099 0 : return true;
1100 5424 : if (IsA(node, RowExpr))
1101 0 : return true;
1102 5424 : if (IsA(node, RowCompareExpr))
1103 0 : return true;
1104 5424 : if (IsA(node, CoalesceExpr))
1105 0 : return true;
1106 5424 : if (IsA(node, MinMaxExpr))
1107 0 : return true;
1108 5424 : if (IsA(node, XmlExpr))
1109 0 : return true;
1110 5424 : if (IsA(node, NullTest))
1111 0 : return true;
1112 5424 : if (IsA(node, BooleanTest))
1113 0 : return true;
1114 :
1115 : /* Check other function-containing nodes */
1116 5424 : if (check_functions_in_node(node, contain_nonstrict_functions_checker,
1117 : context))
1118 0 : return true;
1119 :
1120 5424 : 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 2740 : contain_exec_param(Node *clause, List *param_ids)
1138 : {
1139 2740 : return contain_exec_param_walker(clause, param_ids);
1140 : }
1141 :
1142 : static bool
1143 2950 : contain_exec_param_walker(Node *node, List *param_ids)
1144 : {
1145 2950 : if (node == NULL)
1146 18 : return false;
1147 2932 : 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 2920 : 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 19500 : contain_context_dependent_node(Node *clause)
1180 : {
1181 19500 : int flags = 0;
1182 :
1183 19500 : return contain_context_dependent_node_walker(clause, &flags);
1184 : }
1185 :
1186 : #define CCDN_CASETESTEXPR_OK 0x0001 /* CaseTestExpr okay here? */
1187 :
1188 : static bool
1189 41732 : contain_context_dependent_node_walker(Node *node, int *flags)
1190 : {
1191 41732 : if (node == NULL)
1192 8688 : return false;
1193 33044 : if (IsA(node, CaseTestExpr))
1194 6 : return !(*flags & CCDN_CASETESTEXPR_OK);
1195 33038 : 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 33038 : 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 33038 : 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 4616 : contain_leaked_vars(Node *clause)
1264 : {
1265 4616 : return contain_leaked_vars_walker(clause, NULL);
1266 : }
1267 :
1268 : static bool
1269 4750 : contain_leaked_vars_checker(Oid func_id, void *context)
1270 : {
1271 4750 : return !get_func_leakproof(func_id);
1272 : }
1273 :
1274 : static bool
1275 9454 : contain_leaked_vars_walker(Node *node, void *context)
1276 : {
1277 9454 : if (node == NULL)
1278 0 : return false;
1279 :
1280 9454 : switch (nodeTag(node))
1281 : {
1282 4650 : 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 4650 : break;
1306 :
1307 4750 : 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 4750 : if (check_functions_in_node(node, contain_leaked_vars_checker,
1320 2216 : context) &&
1321 2216 : contain_var_clause(node))
1322 2160 : return true;
1323 2590 : 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 30 : 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 30 : 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 7240 : 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 92990 : find_nonnullable_rels(Node *clause)
1457 : {
1458 92990 : return find_nonnullable_rels_walker(clause, true);
1459 : }
1460 :
1461 : static Relids
1462 589370 : find_nonnullable_rels_walker(Node *node, bool top_level)
1463 : {
1464 589370 : Relids result = NULL;
1465 : ListCell *l;
1466 :
1467 589370 : if (node == NULL)
1468 5384 : return NULL;
1469 583986 : if (IsA(node, Var))
1470 : {
1471 191902 : Var *var = (Var *) node;
1472 :
1473 191902 : if (var->varlevelsup == 0)
1474 191902 : result = bms_make_singleton(var->varno);
1475 : }
1476 392084 : 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 573092 : foreach(l, (List *) node)
1488 : {
1489 363112 : result = bms_join(result,
1490 363112 : find_nonnullable_rels_walker(lfirst(l),
1491 : top_level));
1492 : }
1493 : }
1494 182104 : else if (IsA(node, FuncExpr))
1495 : {
1496 5818 : FuncExpr *expr = (FuncExpr *) node;
1497 :
1498 5818 : if (func_strict(expr->funcid))
1499 5650 : result = find_nonnullable_rels_walker((Node *) expr->args, false);
1500 : }
1501 176286 : else if (IsA(node, OpExpr))
1502 : {
1503 107322 : OpExpr *expr = (OpExpr *) node;
1504 :
1505 107322 : set_opfuncid(expr);
1506 107322 : if (func_strict(expr->opfuncid))
1507 107322 : result = find_nonnullable_rels_walker((Node *) expr->args, false);
1508 : }
1509 68964 : else if (IsA(node, ScalarArrayOpExpr))
1510 : {
1511 7250 : ScalarArrayOpExpr *expr = (ScalarArrayOpExpr *) node;
1512 :
1513 7250 : if (is_strict_saop(expr, true))
1514 7250 : result = find_nonnullable_rels_walker((Node *) expr->args, false);
1515 : }
1516 61714 : else if (IsA(node, BoolExpr))
1517 : {
1518 5232 : BoolExpr *expr = (BoolExpr *) node;
1519 :
1520 5232 : switch (expr->boolop)
1521 : {
1522 398 : case AND_EXPR:
1523 : /* At top level we can just recurse (to the List case) */
1524 398 : if (top_level)
1525 : {
1526 398 : result = find_nonnullable_rels_walker((Node *) expr->args,
1527 : top_level);
1528 398 : 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 6762 : foreach(l, expr->args)
1547 : {
1548 : Relids subresult;
1549 :
1550 6098 : subresult = find_nonnullable_rels_walker(lfirst(l),
1551 : top_level);
1552 6098 : if (result == NULL) /* first subresult? */
1553 3080 : result = subresult;
1554 : else
1555 3018 : 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 6098 : if (bms_is_empty(result))
1562 2416 : break;
1563 : }
1564 3080 : break;
1565 1754 : case NOT_EXPR:
1566 : /* NOT will return null if its arg is null */
1567 1754 : result = find_nonnullable_rels_walker((Node *) expr->args,
1568 : false);
1569 1754 : break;
1570 0 : default:
1571 0 : elog(ERROR, "unrecognized boolop: %d", (int) expr->boolop);
1572 : break;
1573 : }
1574 : }
1575 56482 : else if (IsA(node, RelabelType))
1576 : {
1577 1512 : RelabelType *expr = (RelabelType *) node;
1578 :
1579 1512 : result = find_nonnullable_rels_walker((Node *) expr->arg, top_level);
1580 : }
1581 54970 : 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 54832 : 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 54832 : 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 54832 : 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 54832 : else if (IsA(node, NullTest))
1609 : {
1610 : /* IS NOT NULL can be considered strict, but only at top level */
1611 4208 : NullTest *expr = (NullTest *) node;
1612 :
1613 4208 : if (top_level && expr->nulltesttype == IS_NOT_NULL && !expr->argisrow)
1614 2588 : result = find_nonnullable_rels_walker((Node *) expr->arg, false);
1615 : }
1616 50624 : else if (IsA(node, BooleanTest))
1617 : {
1618 : /* Boolean tests that reject NULL are strict at top level */
1619 70 : BooleanTest *expr = (BooleanTest *) node;
1620 :
1621 70 : if (top_level &&
1622 70 : (expr->booltesttype == IS_TRUE ||
1623 70 : expr->booltesttype == IS_FALSE ||
1624 6 : expr->booltesttype == IS_NOT_UNKNOWN))
1625 64 : result = find_nonnullable_rels_walker((Node *) expr->arg, false);
1626 : }
1627 50554 : else if (IsA(node, SubPlan))
1628 : {
1629 98 : 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 98 : if ((top_level && splan->subLinkType == ANY_SUBLINK) ||
1649 68 : splan->subLinkType == ROWCOMPARE_SUBLINK)
1650 30 : result = find_nonnullable_rels_walker(splan->testexpr, top_level);
1651 : }
1652 50456 : else if (IsA(node, PlaceHolderVar))
1653 : {
1654 464 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
1655 :
1656 : /*
1657 : * If the contained expression forces any rels non-nullable, so does
1658 : * the PHV.
1659 : */
1660 464 : 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 928 : if (phv->phlevelsup == 0 &&
1672 464 : bms_membership(phv->phrels) == BMS_SINGLETON)
1673 278 : result = bms_add_members(result, phv->phrels);
1674 : }
1675 583986 : 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 42006 : find_nonnullable_vars(Node *clause)
1708 : {
1709 42006 : return find_nonnullable_vars_walker(clause, true);
1710 : }
1711 :
1712 : static List *
1713 268324 : find_nonnullable_vars_walker(Node *node, bool top_level)
1714 : {
1715 268324 : List *result = NIL;
1716 : ListCell *l;
1717 :
1718 268324 : if (node == NULL)
1719 500 : return NIL;
1720 267824 : if (IsA(node, Var))
1721 : {
1722 100878 : Var *var = (Var *) node;
1723 :
1724 100878 : if (var->varlevelsup == 0)
1725 100878 : result = mbms_add_member(result,
1726 : var->varno,
1727 100878 : var->varattno - FirstLowInvalidHeapAttributeNumber);
1728 : }
1729 166946 : 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 266452 : foreach(l, (List *) node)
1741 : {
1742 169002 : result = mbms_add_members(result,
1743 169002 : find_nonnullable_vars_walker(lfirst(l),
1744 : top_level));
1745 : }
1746 : }
1747 69496 : else if (IsA(node, FuncExpr))
1748 : {
1749 368 : FuncExpr *expr = (FuncExpr *) node;
1750 :
1751 368 : if (func_strict(expr->funcid))
1752 368 : result = find_nonnullable_vars_walker((Node *) expr->args, false);
1753 : }
1754 69128 : else if (IsA(node, OpExpr))
1755 : {
1756 54022 : OpExpr *expr = (OpExpr *) node;
1757 :
1758 54022 : set_opfuncid(expr);
1759 54022 : if (func_strict(expr->opfuncid))
1760 54022 : result = find_nonnullable_vars_walker((Node *) expr->args, false);
1761 : }
1762 15106 : else if (IsA(node, ScalarArrayOpExpr))
1763 : {
1764 1500 : ScalarArrayOpExpr *expr = (ScalarArrayOpExpr *) node;
1765 :
1766 1500 : if (is_strict_saop(expr, true))
1767 1500 : result = find_nonnullable_vars_walker((Node *) expr->args, false);
1768 : }
1769 13606 : else if (IsA(node, BoolExpr))
1770 : {
1771 354 : BoolExpr *expr = (BoolExpr *) node;
1772 :
1773 354 : 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 54 : case NOT_EXPR:
1824 : /* NOT will return null if its arg is null */
1825 54 : result = find_nonnullable_vars_walker((Node *) expr->args,
1826 : false);
1827 54 : break;
1828 0 : default:
1829 0 : elog(ERROR, "unrecognized boolop: %d", (int) expr->boolop);
1830 : break;
1831 : }
1832 : }
1833 13252 : else if (IsA(node, RelabelType))
1834 : {
1835 534 : RelabelType *expr = (RelabelType *) node;
1836 :
1837 534 : result = find_nonnullable_vars_walker((Node *) expr->arg, top_level);
1838 : }
1839 12718 : 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 12664 : 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 12664 : 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 12664 : 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 12664 : else if (IsA(node, NullTest))
1867 : {
1868 : /* IS NOT NULL can be considered strict, but only at top level */
1869 270 : NullTest *expr = (NullTest *) node;
1870 :
1871 270 : if (top_level && expr->nulltesttype == IS_NOT_NULL && !expr->argisrow)
1872 90 : result = find_nonnullable_vars_walker((Node *) expr->arg, false);
1873 : }
1874 12394 : 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 12394 : 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 12382 : 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 267824 : 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 107724 : find_forced_null_vars(Node *node)
1917 : {
1918 107724 : List *result = NIL;
1919 : Var *var;
1920 : ListCell *l;
1921 :
1922 107724 : if (node == NULL)
1923 4810 : return NIL;
1924 : /* Check single-clause cases using subroutine */
1925 102914 : var = find_forced_null_var(node);
1926 102914 : if (var)
1927 : {
1928 1164 : result = mbms_add_member(result,
1929 : var->varno,
1930 1164 : var->varattno - FirstLowInvalidHeapAttributeNumber);
1931 : }
1932 : /* Otherwise, handle AND-conditions */
1933 101750 : 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 102914 : foreach(l, (List *) node)
1940 : {
1941 61062 : result = mbms_add_members(result,
1942 61062 : find_forced_null_vars((Node *) lfirst(l)));
1943 : }
1944 : }
1945 59898 : else if (IsA(node, BoolExpr))
1946 : {
1947 4022 : 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 4022 : 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 102914 : 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 502744 : find_forced_null_var(Node *node)
1978 : {
1979 502744 : if (node == NULL)
1980 0 : return NULL;
1981 502744 : if (IsA(node, NullTest))
1982 : {
1983 : /* check for var IS NULL */
1984 9944 : NullTest *expr = (NullTest *) node;
1985 :
1986 9944 : if (expr->nulltesttype == IS_NULL && !expr->argisrow)
1987 : {
1988 3664 : Var *var = (Var *) expr->arg;
1989 :
1990 3664 : if (var && IsA(var, Var) &&
1991 3550 : var->varlevelsup == 0)
1992 3550 : return var;
1993 : }
1994 : }
1995 492800 : else if (IsA(node, BooleanTest))
1996 : {
1997 : /* var IS UNKNOWN is equivalent to var IS NULL */
1998 524 : BooleanTest *expr = (BooleanTest *) node;
1999 :
2000 524 : 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 499152 : 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 8750 : is_strict_saop(ScalarArrayOpExpr *expr, bool falseOK)
2027 : {
2028 : Node *rightop;
2029 :
2030 : /* The contained operator must be strict. */
2031 8750 : set_sa_opfuncid(expr);
2032 8750 : if (!func_strict(expr->opfuncid))
2033 0 : return false;
2034 : /* If ANY and falseOK, that's all we need to check. */
2035 8750 : if (expr->useOr && falseOK)
2036 8674 : return true;
2037 : /* Else, we have to see if the array is provably non-empty. */
2038 : Assert(list_length(expr->args) == 2);
2039 76 : rightop = (Node *) lsecond(expr->args);
2040 76 : if (rightop && IsA(rightop, Const))
2041 0 : {
2042 76 : Datum arraydatum = ((Const *) rightop)->constvalue;
2043 76 : bool arrayisnull = ((Const *) rightop)->constisnull;
2044 : ArrayType *arrayval;
2045 : int nitems;
2046 :
2047 76 : if (arrayisnull)
2048 0 : return false;
2049 76 : arrayval = DatumGetArrayTypeP(arraydatum);
2050 76 : nitems = ArrayGetNItems(ARR_NDIM(arrayval), ARR_DIMS(arrayval));
2051 76 : if (nitems > 0)
2052 76 : 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 4788 : 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 4788 : if (!contain_var_clause(clause) &&
2097 4788 : !contain_volatile_functions(clause))
2098 4788 : 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 352038 : is_pseudo_constant_clause_relids(Node *clause, Relids relids)
2109 : {
2110 352038 : if (bms_is_empty(relids) &&
2111 345394 : !contain_volatile_functions(clause))
2112 345394 : return true;
2113 6644 : 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 1680 : NumRelids(PlannerInfo *root, Node *clause)
2131 : {
2132 : int result;
2133 1680 : Relids varnos = pull_varnos(root, clause);
2134 :
2135 1680 : varnos = bms_del_members(varnos, root->outer_join_rels);
2136 1680 : result = bms_num_members(varnos);
2137 1680 : bms_free(varnos);
2138 1680 : return result;
2139 : }
2140 :
2141 : /*
2142 : * CommuteOpExpr: commute a binary operator clause
2143 : *
2144 : * XXX the clause is destructively modified!
2145 : */
2146 : void
2147 15934 : CommuteOpExpr(OpExpr *clause)
2148 : {
2149 : Oid opoid;
2150 : Node *temp;
2151 :
2152 : /* Sanity checks: caller is at fault if these fail */
2153 31868 : if (!is_opclause(clause) ||
2154 15934 : list_length(clause->args) != 2)
2155 0 : elog(ERROR, "cannot commute non-binary-operator clause");
2156 :
2157 15934 : opoid = get_commutator(clause->opno);
2158 :
2159 15934 : 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 15934 : clause->opno = opoid;
2167 15934 : clause->opfuncid = InvalidOid;
2168 : /* opresulttype, opretset, opcollid, inputcollid need not change */
2169 :
2170 15934 : temp = linitial(clause->args);
2171 15934 : linitial(clause->args) = lsecond(clause->args);
2172 15934 : lsecond(clause->args) = temp;
2173 15934 : }
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 1091032 : eval_const_expressions(PlannerInfo *root, Node *node)
2255 : {
2256 : eval_const_expressions_context context;
2257 :
2258 1091032 : if (root)
2259 852778 : context.boundParams = root->glob->boundParams; /* bound Params */
2260 : else
2261 238254 : context.boundParams = NULL;
2262 1091032 : context.root = root; /* for inlined-function dependencies */
2263 1091032 : context.active_fns = NIL; /* nothing being recursively simplified */
2264 1091032 : context.case_val = NULL; /* no CASE being examined */
2265 1091032 : context.estimate = false; /* safe transformations only */
2266 1091032 : 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 752876 : convert_saop_to_hashed_saop(Node *node)
2288 : {
2289 752876 : (void) convert_saop_to_hashed_saop_walker(node, NULL);
2290 752876 : }
2291 :
2292 : static bool
2293 5291168 : convert_saop_to_hashed_saop_walker(Node *node, void *context)
2294 : {
2295 5291168 : if (node == NULL)
2296 128494 : return false;
2297 :
2298 5162674 : if (IsA(node, ScalarArrayOpExpr))
2299 : {
2300 25246 : ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) node;
2301 25246 : Expr *arrayarg = (Expr *) lsecond(saop->args);
2302 : Oid lefthashfunc;
2303 : Oid righthashfunc;
2304 :
2305 25246 : if (arrayarg && IsA(arrayarg, Const) &&
2306 12110 : !((Const *) arrayarg)->constisnull)
2307 : {
2308 12092 : if (saop->useOr)
2309 : {
2310 10658 : if (get_op_hash_functions(saop->opno, &lefthashfunc, &righthashfunc) &&
2311 10370 : lefthashfunc == righthashfunc)
2312 : {
2313 10370 : Datum arrdatum = ((Const *) arrayarg)->constvalue;
2314 10370 : 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 10370 : nitems = ArrayGetNItems(ARR_NDIM(arr), ARR_DIMS(arr));
2323 :
2324 10370 : if (nitems >= MIN_ARRAY_SIZE_FOR_HASHED_SAOP)
2325 : {
2326 : /* Looks good. Fill in the hash functions */
2327 196 : saop->hashfuncid = lefthashfunc;
2328 : }
2329 11706 : return true;
2330 : }
2331 : }
2332 : else /* !saop->useOr */
2333 : {
2334 1434 : 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 2868 : if (OidIsValid(negator) &&
2342 1434 : get_op_hash_functions(negator, &lefthashfunc, &righthashfunc) &&
2343 1336 : lefthashfunc == righthashfunc)
2344 : {
2345 1336 : Datum arrdatum = ((Const *) arrayarg)->constvalue;
2346 1336 : 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 1336 : nitems = ArrayGetNItems(ARR_NDIM(arr), ARR_DIMS(arr));
2355 :
2356 1336 : 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 1336 : return true;
2368 : }
2369 : }
2370 : }
2371 : }
2372 :
2373 5150968 : 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 684432 : estimate_expression_value(PlannerInfo *root, Node *node)
2396 : {
2397 : eval_const_expressions_context context;
2398 :
2399 684432 : context.boundParams = root->glob->boundParams; /* bound Params */
2400 : /* we do not need to mark the plan as depending on inlined functions */
2401 684432 : context.root = NULL;
2402 684432 : context.active_fns = NIL; /* nothing being recursively simplified */
2403 684432 : context.case_val = NULL; /* no CASE being examined */
2404 684432 : context.estimate = true; /* unsafe transformations OK */
2405 684432 : 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 7797426 : 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 7797426 : check_stack_depth();
2446 :
2447 7797426 : if (node == NULL)
2448 343582 : return NULL;
2449 7453844 : switch (nodeTag(node))
2450 : {
2451 233458 : case T_Param:
2452 : {
2453 233458 : Param *param = (Param *) node;
2454 233458 : ParamListInfo paramLI = context->boundParams;
2455 :
2456 : /* Look to see if we've been given a value for this Param */
2457 233458 : if (param->paramkind == PARAM_EXTERN &&
2458 37196 : paramLI != NULL &&
2459 37196 : param->paramid > 0 &&
2460 37196 : 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 37196 : if (paramLI->paramFetch != NULL)
2471 6954 : prm = paramLI->paramFetch(paramLI, param->paramid,
2472 : true, &prmdata);
2473 : else
2474 30242 : 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 37196 : if (OidIsValid(prm->ptype) &&
2483 37196 : prm->ptype == param->paramtype)
2484 : {
2485 : /* OK to substitute parameter value? */
2486 37194 : if (context->estimate ||
2487 37188 : (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 37188 : get_typlenbyval(param->paramtype,
2501 : &typLen, &typByVal);
2502 37188 : if (prm->isnull || typByVal)
2503 24444 : pval = prm->value;
2504 : else
2505 12744 : pval = datumCopy(prm->value, typByVal, typLen);
2506 37188 : con = makeConst(param->paramtype,
2507 : param->paramtypmod,
2508 : param->paramcollid,
2509 : (int) typLen,
2510 : pval,
2511 37188 : prm->isnull,
2512 : typByVal);
2513 37188 : con->location = param->location;
2514 37188 : return (Node *) con;
2515 : }
2516 : }
2517 : }
2518 :
2519 : /*
2520 : * Not replaceable, so just copy the Param (no need to
2521 : * recurse)
2522 : */
2523 196270 : return (Node *) copyObject(param);
2524 : }
2525 3290 : case T_WindowFunc:
2526 : {
2527 3290 : WindowFunc *expr = (WindowFunc *) node;
2528 3290 : 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 3290 : func_tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
2542 3290 : if (!HeapTupleIsValid(func_tuple))
2543 0 : elog(ERROR, "cache lookup failed for function %u", funcid);
2544 :
2545 3290 : args = expand_function_arguments(expr->args,
2546 : false, expr->wintype,
2547 : func_tuple);
2548 :
2549 3290 : ReleaseSysCache(func_tuple);
2550 :
2551 : /* Now, recursively simplify the args (which are a List) */
2552 : args = (List *)
2553 3290 : 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 3290 : eval_const_expressions_mutator((Node *) expr->aggfilter,
2559 : context);
2560 :
2561 : /* And build the replacement WindowFunc node */
2562 3290 : newexpr = makeNode(WindowFunc);
2563 3290 : newexpr->winfnoid = expr->winfnoid;
2564 3290 : newexpr->wintype = expr->wintype;
2565 3290 : newexpr->wincollid = expr->wincollid;
2566 3290 : newexpr->inputcollid = expr->inputcollid;
2567 3290 : newexpr->args = args;
2568 3290 : newexpr->aggfilter = aggfilter;
2569 3290 : newexpr->winref = expr->winref;
2570 3290 : newexpr->winstar = expr->winstar;
2571 3290 : newexpr->winagg = expr->winagg;
2572 3290 : newexpr->location = expr->location;
2573 :
2574 3290 : return (Node *) newexpr;
2575 : }
2576 517542 : case T_FuncExpr:
2577 : {
2578 517542 : FuncExpr *expr = (FuncExpr *) node;
2579 517542 : List *args = expr->args;
2580 : Expr *simple;
2581 : FuncExpr *newexpr;
2582 :
2583 : /*
2584 : * Code for op/func reduction is pretty bulky, so split it out
2585 : * as a separate function. Note: exprTypmod normally returns
2586 : * -1 for a FuncExpr, but not when the node is recognizably a
2587 : * length coercion; we want to preserve the typmod in the
2588 : * eventual Const if so.
2589 : */
2590 517542 : simple = simplify_function(expr->funcid,
2591 : expr->funcresulttype,
2592 : exprTypmod(node),
2593 : expr->funccollid,
2594 : expr->inputcollid,
2595 : &args,
2596 517542 : expr->funcvariadic,
2597 : true,
2598 : true,
2599 : context);
2600 515064 : if (simple) /* successfully simplified it */
2601 167898 : return (Node *) simple;
2602 :
2603 : /*
2604 : * The expression cannot be simplified any further, so build
2605 : * and return a replacement FuncExpr node using the
2606 : * possibly-simplified arguments. Note that we have also
2607 : * converted the argument list to positional notation.
2608 : */
2609 347166 : newexpr = makeNode(FuncExpr);
2610 347166 : newexpr->funcid = expr->funcid;
2611 347166 : newexpr->funcresulttype = expr->funcresulttype;
2612 347166 : newexpr->funcretset = expr->funcretset;
2613 347166 : newexpr->funcvariadic = expr->funcvariadic;
2614 347166 : newexpr->funcformat = expr->funcformat;
2615 347166 : newexpr->funccollid = expr->funccollid;
2616 347166 : newexpr->inputcollid = expr->inputcollid;
2617 347166 : newexpr->args = args;
2618 347166 : newexpr->location = expr->location;
2619 347166 : return (Node *) newexpr;
2620 : }
2621 611372 : case T_OpExpr:
2622 : {
2623 611372 : OpExpr *expr = (OpExpr *) node;
2624 611372 : List *args = expr->args;
2625 : Expr *simple;
2626 : OpExpr *newexpr;
2627 :
2628 : /*
2629 : * Need to get OID of underlying function. Okay to scribble
2630 : * on input to this extent.
2631 : */
2632 611372 : set_opfuncid(expr);
2633 :
2634 : /*
2635 : * Code for op/func reduction is pretty bulky, so split it out
2636 : * as a separate function.
2637 : */
2638 611372 : simple = simplify_function(expr->opfuncid,
2639 : expr->opresulttype, -1,
2640 : expr->opcollid,
2641 : expr->inputcollid,
2642 : &args,
2643 : false,
2644 : true,
2645 : true,
2646 : context);
2647 610274 : if (simple) /* successfully simplified it */
2648 18012 : return (Node *) simple;
2649 :
2650 : /*
2651 : * If the operator is boolean equality or inequality, we know
2652 : * how to simplify cases involving one constant and one
2653 : * non-constant argument.
2654 : */
2655 592262 : if (expr->opno == BooleanEqualOperator ||
2656 591854 : expr->opno == BooleanNotEqualOperator)
2657 : {
2658 570 : simple = (Expr *) simplify_boolean_equality(expr->opno,
2659 : args);
2660 570 : if (simple) /* successfully simplified it */
2661 392 : return (Node *) simple;
2662 : }
2663 :
2664 : /*
2665 : * The expression cannot be simplified any further, so build
2666 : * and return a replacement OpExpr node using the
2667 : * possibly-simplified arguments.
2668 : */
2669 591870 : newexpr = makeNode(OpExpr);
2670 591870 : newexpr->opno = expr->opno;
2671 591870 : newexpr->opfuncid = expr->opfuncid;
2672 591870 : newexpr->opresulttype = expr->opresulttype;
2673 591870 : newexpr->opretset = expr->opretset;
2674 591870 : newexpr->opcollid = expr->opcollid;
2675 591870 : newexpr->inputcollid = expr->inputcollid;
2676 591870 : newexpr->args = args;
2677 591870 : newexpr->location = expr->location;
2678 591870 : return (Node *) newexpr;
2679 : }
2680 858 : case T_DistinctExpr:
2681 : {
2682 858 : DistinctExpr *expr = (DistinctExpr *) node;
2683 : List *args;
2684 : ListCell *arg;
2685 858 : bool has_null_input = false;
2686 858 : bool all_null_input = true;
2687 858 : bool has_nonconst_input = false;
2688 : Expr *simple;
2689 : DistinctExpr *newexpr;
2690 :
2691 : /*
2692 : * Reduce constants in the DistinctExpr's arguments. We know
2693 : * args is either NIL or a List node, so we can call
2694 : * expression_tree_mutator directly rather than recursing to
2695 : * self.
2696 : */
2697 858 : args = (List *) expression_tree_mutator((Node *) expr->args,
2698 : eval_const_expressions_mutator,
2699 : (void *) context);
2700 :
2701 : /*
2702 : * We must do our own check for NULLs because DistinctExpr has
2703 : * different results for NULL input than the underlying
2704 : * operator does.
2705 : */
2706 2574 : foreach(arg, args)
2707 : {
2708 1716 : if (IsA(lfirst(arg), Const))
2709 : {
2710 90 : has_null_input |= ((Const *) lfirst(arg))->constisnull;
2711 90 : all_null_input &= ((Const *) lfirst(arg))->constisnull;
2712 : }
2713 : else
2714 1626 : has_nonconst_input = true;
2715 : }
2716 :
2717 : /* all constants? then can optimize this out */
2718 858 : if (!has_nonconst_input)
2719 : {
2720 : /* all nulls? then not distinct */
2721 24 : if (all_null_input)
2722 0 : return makeBoolConst(false, false);
2723 :
2724 : /* one null? then distinct */
2725 24 : if (has_null_input)
2726 0 : return makeBoolConst(true, false);
2727 :
2728 : /* otherwise try to evaluate the '=' operator */
2729 : /* (NOT okay to try to inline it, though!) */
2730 :
2731 : /*
2732 : * Need to get OID of underlying function. Okay to
2733 : * scribble on input to this extent.
2734 : */
2735 24 : set_opfuncid((OpExpr *) expr); /* rely on struct
2736 : * equivalence */
2737 :
2738 : /*
2739 : * Code for op/func reduction is pretty bulky, so split it
2740 : * out as a separate function.
2741 : */
2742 24 : simple = simplify_function(expr->opfuncid,
2743 : expr->opresulttype, -1,
2744 : expr->opcollid,
2745 : expr->inputcollid,
2746 : &args,
2747 : false,
2748 : false,
2749 : false,
2750 : context);
2751 24 : if (simple) /* successfully simplified it */
2752 : {
2753 : /*
2754 : * Since the underlying operator is "=", must negate
2755 : * its result
2756 : */
2757 24 : Const *csimple = castNode(Const, simple);
2758 :
2759 24 : csimple->constvalue =
2760 24 : BoolGetDatum(!DatumGetBool(csimple->constvalue));
2761 24 : return (Node *) csimple;
2762 : }
2763 : }
2764 :
2765 : /*
2766 : * The expression cannot be simplified any further, so build
2767 : * and return a replacement DistinctExpr node using the
2768 : * possibly-simplified arguments.
2769 : */
2770 834 : newexpr = makeNode(DistinctExpr);
2771 834 : newexpr->opno = expr->opno;
2772 834 : newexpr->opfuncid = expr->opfuncid;
2773 834 : newexpr->opresulttype = expr->opresulttype;
2774 834 : newexpr->opretset = expr->opretset;
2775 834 : newexpr->opcollid = expr->opcollid;
2776 834 : newexpr->inputcollid = expr->inputcollid;
2777 834 : newexpr->args = args;
2778 834 : newexpr->location = expr->location;
2779 834 : return (Node *) newexpr;
2780 : }
2781 190 : case T_NullIfExpr:
2782 : {
2783 : NullIfExpr *expr;
2784 : ListCell *arg;
2785 190 : bool has_nonconst_input = false;
2786 :
2787 : /* Copy the node and const-simplify its arguments */
2788 190 : expr = (NullIfExpr *) ece_generic_processing(node);
2789 :
2790 : /* If either argument is NULL they can't be equal */
2791 564 : foreach(arg, expr->args)
2792 : {
2793 380 : if (!IsA(lfirst(arg), Const))
2794 158 : has_nonconst_input = true;
2795 222 : else if (((Const *) lfirst(arg))->constisnull)
2796 6 : return (Node *) linitial(expr->args);
2797 : }
2798 :
2799 : /*
2800 : * Need to get OID of underlying function before checking if
2801 : * the function is OK to evaluate.
2802 : */
2803 184 : set_opfuncid((OpExpr *) expr);
2804 :
2805 222 : if (!has_nonconst_input &&
2806 38 : ece_function_is_safe(expr->opfuncid, context))
2807 38 : return ece_evaluate_expr(expr);
2808 :
2809 146 : return (Node *) expr;
2810 : }
2811 31602 : case T_ScalarArrayOpExpr:
2812 : {
2813 : ScalarArrayOpExpr *saop;
2814 :
2815 : /* Copy the node and const-simplify its arguments */
2816 31602 : saop = (ScalarArrayOpExpr *) ece_generic_processing(node);
2817 :
2818 : /* Make sure we know underlying function */
2819 31602 : set_sa_opfuncid(saop);
2820 :
2821 : /*
2822 : * If all arguments are Consts, and it's a safe function, we
2823 : * can fold to a constant
2824 : */
2825 31794 : if (ece_all_arguments_const(saop) &&
2826 192 : ece_function_is_safe(saop->opfuncid, context))
2827 192 : return ece_evaluate_expr(saop);
2828 31410 : return (Node *) saop;
2829 : }
2830 145900 : case T_BoolExpr:
2831 : {
2832 145900 : BoolExpr *expr = (BoolExpr *) node;
2833 :
2834 145900 : switch (expr->boolop)
2835 : {
2836 12354 : case OR_EXPR:
2837 : {
2838 : List *newargs;
2839 12354 : bool haveNull = false;
2840 12354 : bool forceTrue = false;
2841 :
2842 12354 : newargs = simplify_or_arguments(expr->args,
2843 : context,
2844 : &haveNull,
2845 : &forceTrue);
2846 12354 : if (forceTrue)
2847 148 : return makeBoolConst(true, false);
2848 12206 : if (haveNull)
2849 30 : newargs = lappend(newargs,
2850 30 : makeBoolConst(false, true));
2851 : /* If all the inputs are FALSE, result is FALSE */
2852 12206 : if (newargs == NIL)
2853 6 : return makeBoolConst(false, false);
2854 :
2855 : /*
2856 : * If only one nonconst-or-NULL input, it's the
2857 : * result
2858 : */
2859 12200 : if (list_length(newargs) == 1)
2860 96 : return (Node *) linitial(newargs);
2861 : /* Else we still need an OR node */
2862 12104 : return (Node *) make_orclause(newargs);
2863 : }
2864 121594 : case AND_EXPR:
2865 : {
2866 : List *newargs;
2867 121594 : bool haveNull = false;
2868 121594 : bool forceFalse = false;
2869 :
2870 121594 : newargs = simplify_and_arguments(expr->args,
2871 : context,
2872 : &haveNull,
2873 : &forceFalse);
2874 121594 : if (forceFalse)
2875 1466 : return makeBoolConst(false, false);
2876 120128 : if (haveNull)
2877 6 : newargs = lappend(newargs,
2878 6 : makeBoolConst(false, true));
2879 : /* If all the inputs are TRUE, result is TRUE */
2880 120128 : if (newargs == NIL)
2881 364 : return makeBoolConst(true, false);
2882 :
2883 : /*
2884 : * If only one nonconst-or-NULL input, it's the
2885 : * result
2886 : */
2887 119764 : if (list_length(newargs) == 1)
2888 26 : return (Node *) linitial(newargs);
2889 : /* Else we still need an AND node */
2890 119738 : return (Node *) make_andclause(newargs);
2891 : }
2892 11952 : case NOT_EXPR:
2893 : {
2894 : Node *arg;
2895 :
2896 : Assert(list_length(expr->args) == 1);
2897 11952 : arg = eval_const_expressions_mutator(linitial(expr->args),
2898 : context);
2899 :
2900 : /*
2901 : * Use negate_clause() to see if we can simplify
2902 : * away the NOT.
2903 : */
2904 11952 : return negate_clause(arg);
2905 : }
2906 0 : default:
2907 0 : elog(ERROR, "unrecognized boolop: %d",
2908 : (int) expr->boolop);
2909 : break;
2910 : }
2911 : break;
2912 : }
2913 :
2914 690 : case T_JsonValueExpr:
2915 : {
2916 690 : JsonValueExpr *jve = (JsonValueExpr *) node;
2917 : Node *formatted;
2918 :
2919 690 : formatted = eval_const_expressions_mutator((Node *) jve->formatted_expr,
2920 : context);
2921 690 : if (formatted && IsA(formatted, Const))
2922 510 : return formatted;
2923 180 : break;
2924 : }
2925 :
2926 504 : case T_SubPlan:
2927 : case T_AlternativeSubPlan:
2928 :
2929 : /*
2930 : * Return a SubPlan unchanged --- too late to do anything with it.
2931 : *
2932 : * XXX should we ereport() here instead? Probably this routine
2933 : * should never be invoked after SubPlan creation.
2934 : */
2935 504 : return node;
2936 133708 : case T_RelabelType:
2937 : {
2938 133708 : RelabelType *relabel = (RelabelType *) node;
2939 : Node *arg;
2940 :
2941 : /* Simplify the input ... */
2942 133708 : arg = eval_const_expressions_mutator((Node *) relabel->arg,
2943 : context);
2944 : /* ... and attach a new RelabelType node, if needed */
2945 133708 : return applyRelabelType(arg,
2946 : relabel->resulttype,
2947 : relabel->resulttypmod,
2948 : relabel->resultcollid,
2949 : relabel->relabelformat,
2950 : relabel->location,
2951 : true);
2952 : }
2953 23666 : case T_CoerceViaIO:
2954 : {
2955 23666 : CoerceViaIO *expr = (CoerceViaIO *) node;
2956 : List *args;
2957 : Oid outfunc;
2958 : bool outtypisvarlena;
2959 : Oid infunc;
2960 : Oid intypioparam;
2961 : Expr *simple;
2962 : CoerceViaIO *newexpr;
2963 :
2964 : /* Make a List so we can use simplify_function */
2965 23666 : args = list_make1(expr->arg);
2966 :
2967 : /*
2968 : * CoerceViaIO represents calling the source type's output
2969 : * function then the result type's input function. So, try to
2970 : * simplify it as though it were a stack of two such function
2971 : * calls. First we need to know what the functions are.
2972 : *
2973 : * Note that the coercion functions are assumed not to care
2974 : * about input collation, so we just pass InvalidOid for that.
2975 : */
2976 23666 : getTypeOutputInfo(exprType((Node *) expr->arg),
2977 : &outfunc, &outtypisvarlena);
2978 23666 : getTypeInputInfo(expr->resulttype,
2979 : &infunc, &intypioparam);
2980 :
2981 23666 : simple = simplify_function(outfunc,
2982 : CSTRINGOID, -1,
2983 : InvalidOid,
2984 : InvalidOid,
2985 : &args,
2986 : false,
2987 : true,
2988 : true,
2989 : context);
2990 23666 : if (simple) /* successfully simplified output fn */
2991 : {
2992 : /*
2993 : * Input functions may want 1 to 3 arguments. We always
2994 : * supply all three, trusting that nothing downstream will
2995 : * complain.
2996 : */
2997 2046 : args = list_make3(simple,
2998 : makeConst(OIDOID,
2999 : -1,
3000 : InvalidOid,
3001 : sizeof(Oid),
3002 : ObjectIdGetDatum(intypioparam),
3003 : false,
3004 : true),
3005 : makeConst(INT4OID,
3006 : -1,
3007 : InvalidOid,
3008 : sizeof(int32),
3009 : Int32GetDatum(-1),
3010 : false,
3011 : true));
3012 :
3013 2046 : simple = simplify_function(infunc,
3014 : expr->resulttype, -1,
3015 : expr->resultcollid,
3016 : InvalidOid,
3017 : &args,
3018 : false,
3019 : false,
3020 : true,
3021 : context);
3022 1994 : if (simple) /* successfully simplified input fn */
3023 1944 : return (Node *) simple;
3024 : }
3025 :
3026 : /*
3027 : * The expression cannot be simplified any further, so build
3028 : * and return a replacement CoerceViaIO node using the
3029 : * possibly-simplified argument.
3030 : */
3031 21670 : newexpr = makeNode(CoerceViaIO);
3032 21670 : newexpr->arg = (Expr *) linitial(args);
3033 21670 : newexpr->resulttype = expr->resulttype;
3034 21670 : newexpr->resultcollid = expr->resultcollid;
3035 21670 : newexpr->coerceformat = expr->coerceformat;
3036 21670 : newexpr->location = expr->location;
3037 21670 : return (Node *) newexpr;
3038 : }
3039 8830 : case T_ArrayCoerceExpr:
3040 : {
3041 8830 : ArrayCoerceExpr *ac = makeNode(ArrayCoerceExpr);
3042 : Node *save_case_val;
3043 :
3044 : /*
3045 : * Copy the node and const-simplify its arguments. We can't
3046 : * use ece_generic_processing() here because we need to mess
3047 : * with case_val only while processing the elemexpr.
3048 : */
3049 8830 : memcpy(ac, node, sizeof(ArrayCoerceExpr));
3050 8830 : ac->arg = (Expr *)
3051 8830 : eval_const_expressions_mutator((Node *) ac->arg,
3052 : context);
3053 :
3054 : /*
3055 : * Set up for the CaseTestExpr node contained in the elemexpr.
3056 : * We must prevent it from absorbing any outer CASE value.
3057 : */
3058 8830 : save_case_val = context->case_val;
3059 8830 : context->case_val = NULL;
3060 :
3061 8830 : ac->elemexpr = (Expr *)
3062 8830 : eval_const_expressions_mutator((Node *) ac->elemexpr,
3063 : context);
3064 :
3065 8830 : context->case_val = save_case_val;
3066 :
3067 : /*
3068 : * If constant argument and the per-element expression is
3069 : * immutable, we can simplify the whole thing to a constant.
3070 : * Exception: although contain_mutable_functions considers
3071 : * CoerceToDomain immutable for historical reasons, let's not
3072 : * do so here; this ensures coercion to an array-over-domain
3073 : * does not apply the domain's constraints until runtime.
3074 : */
3075 8830 : if (ac->arg && IsA(ac->arg, Const) &&
3076 992 : ac->elemexpr && !IsA(ac->elemexpr, CoerceToDomain) &&
3077 968 : !contain_mutable_functions((Node *) ac->elemexpr))
3078 968 : return ece_evaluate_expr(ac);
3079 :
3080 7862 : return (Node *) ac;
3081 : }
3082 7704 : case T_CollateExpr:
3083 : {
3084 : /*
3085 : * We replace CollateExpr with RelabelType, so as to improve
3086 : * uniformity of expression representation and thus simplify
3087 : * comparison of expressions. Hence this looks very nearly
3088 : * the same as the RelabelType case, and we can apply the same
3089 : * optimizations to avoid unnecessary RelabelTypes.
3090 : */
3091 7704 : CollateExpr *collate = (CollateExpr *) node;
3092 : Node *arg;
3093 :
3094 : /* Simplify the input ... */
3095 7704 : arg = eval_const_expressions_mutator((Node *) collate->arg,
3096 : context);
3097 : /* ... and attach a new RelabelType node, if needed */
3098 7704 : return applyRelabelType(arg,
3099 : exprType(arg),
3100 : exprTypmod(arg),
3101 : collate->collOid,
3102 : COERCE_IMPLICIT_CAST,
3103 : collate->location,
3104 : true);
3105 : }
3106 46312 : case T_CaseExpr:
3107 : {
3108 : /*----------
3109 : * CASE expressions can be simplified if there are constant
3110 : * condition clauses:
3111 : * FALSE (or NULL): drop the alternative
3112 : * TRUE: drop all remaining alternatives
3113 : * If the first non-FALSE alternative is a constant TRUE,
3114 : * we can simplify the entire CASE to that alternative's
3115 : * expression. If there are no non-FALSE alternatives,
3116 : * we simplify the entire CASE to the default result (ELSE).
3117 : *
3118 : * If we have a simple-form CASE with constant test
3119 : * expression, we substitute the constant value for contained
3120 : * CaseTestExpr placeholder nodes, so that we have the
3121 : * opportunity to reduce constant test conditions. For
3122 : * example this allows
3123 : * CASE 0 WHEN 0 THEN 1 ELSE 1/0 END
3124 : * to reduce to 1 rather than drawing a divide-by-0 error.
3125 : * Note that when the test expression is constant, we don't
3126 : * have to include it in the resulting CASE; for example
3127 : * CASE 0 WHEN x THEN y ELSE z END
3128 : * is transformed by the parser to
3129 : * CASE 0 WHEN CaseTestExpr = x THEN y ELSE z END
3130 : * which we can simplify to
3131 : * CASE WHEN 0 = x THEN y ELSE z END
3132 : * It is not necessary for the executor to evaluate the "arg"
3133 : * expression when executing the CASE, since any contained
3134 : * CaseTestExprs that might have referred to it will have been
3135 : * replaced by the constant.
3136 : *----------
3137 : */
3138 46312 : CaseExpr *caseexpr = (CaseExpr *) node;
3139 : CaseExpr *newcase;
3140 : Node *save_case_val;
3141 : Node *newarg;
3142 : List *newargs;
3143 : bool const_true_cond;
3144 46312 : Node *defresult = NULL;
3145 : ListCell *arg;
3146 :
3147 : /* Simplify the test expression, if any */
3148 46312 : newarg = eval_const_expressions_mutator((Node *) caseexpr->arg,
3149 : context);
3150 :
3151 : /* Set up for contained CaseTestExpr nodes */
3152 46312 : save_case_val = context->case_val;
3153 46312 : if (newarg && IsA(newarg, Const))
3154 : {
3155 18 : context->case_val = newarg;
3156 18 : newarg = NULL; /* not needed anymore, see above */
3157 : }
3158 : else
3159 46294 : context->case_val = NULL;
3160 :
3161 : /* Simplify the WHEN clauses */
3162 46312 : newargs = NIL;
3163 46312 : const_true_cond = false;
3164 123178 : foreach(arg, caseexpr->args)
3165 : {
3166 77192 : CaseWhen *oldcasewhen = lfirst_node(CaseWhen, arg);
3167 : Node *casecond;
3168 : Node *caseresult;
3169 :
3170 : /* Simplify this alternative's test condition */
3171 77192 : casecond = eval_const_expressions_mutator((Node *) oldcasewhen->expr,
3172 : context);
3173 :
3174 : /*
3175 : * If the test condition is constant FALSE (or NULL), then
3176 : * drop this WHEN clause completely, without processing
3177 : * the result.
3178 : */
3179 77192 : if (casecond && IsA(casecond, Const))
3180 : {
3181 986 : Const *const_input = (Const *) casecond;
3182 :
3183 986 : if (const_input->constisnull ||
3184 986 : !DatumGetBool(const_input->constvalue))
3185 666 : continue; /* drop alternative with FALSE cond */
3186 : /* Else it's constant TRUE */
3187 320 : const_true_cond = true;
3188 : }
3189 :
3190 : /* Simplify this alternative's result value */
3191 76526 : caseresult = eval_const_expressions_mutator((Node *) oldcasewhen->result,
3192 : context);
3193 :
3194 : /* If non-constant test condition, emit a new WHEN node */
3195 76520 : if (!const_true_cond)
3196 : {
3197 76200 : CaseWhen *newcasewhen = makeNode(CaseWhen);
3198 :
3199 76200 : newcasewhen->expr = (Expr *) casecond;
3200 76200 : newcasewhen->result = (Expr *) caseresult;
3201 76200 : newcasewhen->location = oldcasewhen->location;
3202 76200 : newargs = lappend(newargs, newcasewhen);
3203 76200 : continue;
3204 : }
3205 :
3206 : /*
3207 : * Found a TRUE condition, so none of the remaining
3208 : * alternatives can be reached. We treat the result as
3209 : * the default result.
3210 : */
3211 320 : defresult = caseresult;
3212 320 : break;
3213 : }
3214 :
3215 : /* Simplify the default result, unless we replaced it above */
3216 46306 : if (!const_true_cond)
3217 45986 : defresult = eval_const_expressions_mutator((Node *) caseexpr->defresult,
3218 : context);
3219 :
3220 46306 : context->case_val = save_case_val;
3221 :
3222 : /*
3223 : * If no non-FALSE alternatives, CASE reduces to the default
3224 : * result
3225 : */
3226 46306 : if (newargs == NIL)
3227 536 : return defresult;
3228 : /* Otherwise we need a new CASE node */
3229 45770 : newcase = makeNode(CaseExpr);
3230 45770 : newcase->casetype = caseexpr->casetype;
3231 45770 : newcase->casecollid = caseexpr->casecollid;
3232 45770 : newcase->arg = (Expr *) newarg;
3233 45770 : newcase->args = newargs;
3234 45770 : newcase->defresult = (Expr *) defresult;
3235 45770 : newcase->location = caseexpr->location;
3236 45770 : return (Node *) newcase;
3237 : }
3238 28888 : case T_CaseTestExpr:
3239 : {
3240 : /*
3241 : * If we know a constant test value for the current CASE
3242 : * construct, substitute it for the placeholder. Else just
3243 : * return the placeholder as-is.
3244 : */
3245 28888 : if (context->case_val)
3246 24 : return copyObject(context->case_val);
3247 : else
3248 28864 : return copyObject(node);
3249 : }
3250 49806 : case T_SubscriptingRef:
3251 : case T_ArrayExpr:
3252 : case T_RowExpr:
3253 : case T_MinMaxExpr:
3254 : {
3255 : /*
3256 : * Generic handling for node types whose own processing is
3257 : * known to be immutable, and for which we need no smarts
3258 : * beyond "simplify if all inputs are constants".
3259 : *
3260 : * Treating SubscriptingRef this way assumes that subscripting
3261 : * fetch and assignment are both immutable. This constrains
3262 : * type-specific subscripting implementations; maybe we should
3263 : * relax it someday.
3264 : *
3265 : * Treating MinMaxExpr this way amounts to assuming that the
3266 : * btree comparison function it calls is immutable; see the
3267 : * reasoning in contain_mutable_functions_walker.
3268 : */
3269 :
3270 : /* Copy the node and const-simplify its arguments */
3271 49806 : node = ece_generic_processing(node);
3272 : /* If all arguments are Consts, we can fold to a constant */
3273 49806 : if (ece_all_arguments_const(node))
3274 25970 : return ece_evaluate_expr(node);
3275 23836 : return node;
3276 : }
3277 2540 : case T_CoalesceExpr:
3278 : {
3279 2540 : CoalesceExpr *coalesceexpr = (CoalesceExpr *) node;
3280 : CoalesceExpr *newcoalesce;
3281 : List *newargs;
3282 : ListCell *arg;
3283 :
3284 2540 : newargs = NIL;
3285 6076 : foreach(arg, coalesceexpr->args)
3286 : {
3287 : Node *e;
3288 :
3289 5014 : e = eval_const_expressions_mutator((Node *) lfirst(arg),
3290 : context);
3291 :
3292 : /*
3293 : * We can remove null constants from the list. For a
3294 : * non-null constant, if it has not been preceded by any
3295 : * other non-null-constant expressions then it is the
3296 : * result. Otherwise, it's the next argument, but we can
3297 : * drop following arguments since they will never be
3298 : * reached.
3299 : */
3300 5014 : if (IsA(e, Const))
3301 : {
3302 1516 : if (((Const *) e)->constisnull)
3303 38 : continue; /* drop null constant */
3304 1478 : if (newargs == NIL)
3305 74 : return e; /* first expr */
3306 1404 : newargs = lappend(newargs, e);
3307 1404 : break;
3308 : }
3309 3498 : newargs = lappend(newargs, e);
3310 : }
3311 :
3312 : /*
3313 : * If all the arguments were constant null, the result is just
3314 : * null
3315 : */
3316 2466 : if (newargs == NIL)
3317 0 : return (Node *) makeNullConst(coalesceexpr->coalescetype,
3318 : -1,
3319 : coalesceexpr->coalescecollid);
3320 :
3321 2466 : newcoalesce = makeNode(CoalesceExpr);
3322 2466 : newcoalesce->coalescetype = coalesceexpr->coalescetype;
3323 2466 : newcoalesce->coalescecollid = coalesceexpr->coalescecollid;
3324 2466 : newcoalesce->args = newargs;
3325 2466 : newcoalesce->location = coalesceexpr->location;
3326 2466 : return (Node *) newcoalesce;
3327 : }
3328 4728 : case T_SQLValueFunction:
3329 : {
3330 : /*
3331 : * All variants of SQLValueFunction are stable, so if we are
3332 : * estimating the expression's value, we should evaluate the
3333 : * current function value. Otherwise just copy.
3334 : */
3335 4728 : SQLValueFunction *svf = (SQLValueFunction *) node;
3336 :
3337 4728 : if (context->estimate)
3338 804 : return (Node *) evaluate_expr((Expr *) svf,
3339 : svf->type,
3340 : svf->typmod,
3341 : InvalidOid);
3342 : else
3343 3924 : return copyObject((Node *) svf);
3344 : }
3345 4384 : case T_FieldSelect:
3346 : {
3347 : /*
3348 : * We can optimize field selection from a whole-row Var into a
3349 : * simple Var. (This case won't be generated directly by the
3350 : * parser, because ParseComplexProjection short-circuits it.
3351 : * But it can arise while simplifying functions.) Also, we
3352 : * can optimize field selection from a RowExpr construct, or
3353 : * of course from a constant.
3354 : *
3355 : * However, replacing a whole-row Var in this way has a
3356 : * pitfall: if we've already built the rel targetlist for the
3357 : * source relation, then the whole-row Var is scheduled to be
3358 : * produced by the relation scan, but the simple Var probably
3359 : * isn't, which will lead to a failure in setrefs.c. This is
3360 : * not a problem when handling simple single-level queries, in
3361 : * which expression simplification always happens first. It
3362 : * is a risk for lateral references from subqueries, though.
3363 : * To avoid such failures, don't optimize uplevel references.
3364 : *
3365 : * We must also check that the declared type of the field is
3366 : * still the same as when the FieldSelect was created --- this
3367 : * can change if someone did ALTER COLUMN TYPE on the rowtype.
3368 : * If it isn't, we skip the optimization; the case will
3369 : * probably fail at runtime, but that's not our problem here.
3370 : */
3371 4384 : FieldSelect *fselect = (FieldSelect *) node;
3372 : FieldSelect *newfselect;
3373 : Node *arg;
3374 :
3375 4384 : arg = eval_const_expressions_mutator((Node *) fselect->arg,
3376 : context);
3377 4384 : if (arg && IsA(arg, Var) &&
3378 528 : ((Var *) arg)->varattno == InvalidAttrNumber &&
3379 90 : ((Var *) arg)->varlevelsup == 0)
3380 : {
3381 78 : if (rowtype_field_matches(((Var *) arg)->vartype,
3382 78 : fselect->fieldnum,
3383 : fselect->resulttype,
3384 : fselect->resulttypmod,
3385 : fselect->resultcollid))
3386 : {
3387 : Var *newvar;
3388 :
3389 78 : newvar = makeVar(((Var *) arg)->varno,
3390 78 : fselect->fieldnum,
3391 : fselect->resulttype,
3392 : fselect->resulttypmod,
3393 : fselect->resultcollid,
3394 : ((Var *) arg)->varlevelsup);
3395 : /* New Var is nullable by same rels as the old one */
3396 78 : newvar->varnullingrels = ((Var *) arg)->varnullingrels;
3397 78 : return (Node *) newvar;
3398 : }
3399 : }
3400 4306 : if (arg && IsA(arg, RowExpr))
3401 : {
3402 24 : RowExpr *rowexpr = (RowExpr *) arg;
3403 :
3404 48 : if (fselect->fieldnum > 0 &&
3405 24 : fselect->fieldnum <= list_length(rowexpr->args))
3406 : {
3407 24 : Node *fld = (Node *) list_nth(rowexpr->args,
3408 24 : fselect->fieldnum - 1);
3409 :
3410 24 : if (rowtype_field_matches(rowexpr->row_typeid,
3411 24 : fselect->fieldnum,
3412 : fselect->resulttype,
3413 : fselect->resulttypmod,
3414 24 : fselect->resultcollid) &&
3415 48 : fselect->resulttype == exprType(fld) &&
3416 48 : fselect->resulttypmod == exprTypmod(fld) &&
3417 24 : fselect->resultcollid == exprCollation(fld))
3418 24 : return fld;
3419 : }
3420 : }
3421 4282 : newfselect = makeNode(FieldSelect);
3422 4282 : newfselect->arg = (Expr *) arg;
3423 4282 : newfselect->fieldnum = fselect->fieldnum;
3424 4282 : newfselect->resulttype = fselect->resulttype;
3425 4282 : newfselect->resulttypmod = fselect->resulttypmod;
3426 4282 : newfselect->resultcollid = fselect->resultcollid;
3427 4282 : if (arg && IsA(arg, Const))
3428 : {
3429 424 : Const *con = (Const *) arg;
3430 :
3431 424 : if (rowtype_field_matches(con->consttype,
3432 424 : newfselect->fieldnum,
3433 : newfselect->resulttype,
3434 : newfselect->resulttypmod,
3435 : newfselect->resultcollid))
3436 424 : return ece_evaluate_expr(newfselect);
3437 : }
3438 3858 : return (Node *) newfselect;
3439 : }
3440 33844 : case T_NullTest:
3441 : {
3442 33844 : NullTest *ntest = (NullTest *) node;
3443 : NullTest *newntest;
3444 : Node *arg;
3445 :
3446 33844 : arg = eval_const_expressions_mutator((Node *) ntest->arg,
3447 : context);
3448 33842 : if (ntest->argisrow && arg && IsA(arg, RowExpr))
3449 : {
3450 : /*
3451 : * We break ROW(...) IS [NOT] NULL into separate tests on
3452 : * its component fields. This form is usually more
3453 : * efficient to evaluate, as well as being more amenable
3454 : * to optimization.
3455 : */
3456 30 : RowExpr *rarg = (RowExpr *) arg;
3457 30 : List *newargs = NIL;
3458 : ListCell *l;
3459 :
3460 120 : foreach(l, rarg->args)
3461 : {
3462 90 : Node *relem = (Node *) lfirst(l);
3463 :
3464 : /*
3465 : * A constant field refutes the whole NullTest if it's
3466 : * of the wrong nullness; else we can discard it.
3467 : */
3468 90 : if (relem && IsA(relem, Const))
3469 : {
3470 0 : Const *carg = (Const *) relem;
3471 :
3472 0 : if (carg->constisnull ?
3473 0 : (ntest->nulltesttype == IS_NOT_NULL) :
3474 0 : (ntest->nulltesttype == IS_NULL))
3475 0 : return makeBoolConst(false, false);
3476 0 : continue;
3477 : }
3478 :
3479 : /*
3480 : * Else, make a scalar (argisrow == false) NullTest
3481 : * for this field. Scalar semantics are required
3482 : * because IS [NOT] NULL doesn't recurse; see comments
3483 : * in ExecEvalRowNullInt().
3484 : */
3485 90 : newntest = makeNode(NullTest);
3486 90 : newntest->arg = (Expr *) relem;
3487 90 : newntest->nulltesttype = ntest->nulltesttype;
3488 90 : newntest->argisrow = false;
3489 90 : newntest->location = ntest->location;
3490 90 : newargs = lappend(newargs, newntest);
3491 : }
3492 : /* If all the inputs were constants, result is TRUE */
3493 30 : if (newargs == NIL)
3494 0 : return makeBoolConst(true, false);
3495 : /* If only one nonconst input, it's the result */
3496 30 : if (list_length(newargs) == 1)
3497 0 : return (Node *) linitial(newargs);
3498 : /* Else we need an AND node */
3499 30 : return (Node *) make_andclause(newargs);
3500 : }
3501 33812 : if (!ntest->argisrow && arg && IsA(arg, Const))
3502 : {
3503 372 : Const *carg = (Const *) arg;
3504 : bool result;
3505 :
3506 372 : switch (ntest->nulltesttype)
3507 : {
3508 312 : case IS_NULL:
3509 312 : result = carg->constisnull;
3510 312 : break;
3511 60 : case IS_NOT_NULL:
3512 60 : result = !carg->constisnull;
3513 60 : break;
3514 0 : default:
3515 0 : elog(ERROR, "unrecognized nulltesttype: %d",
3516 : (int) ntest->nulltesttype);
3517 : result = false; /* keep compiler quiet */
3518 : break;
3519 : }
3520 :
3521 372 : return makeBoolConst(result, false);
3522 : }
3523 :
3524 33440 : newntest = makeNode(NullTest);
3525 33440 : newntest->arg = (Expr *) arg;
3526 33440 : newntest->nulltesttype = ntest->nulltesttype;
3527 33440 : newntest->argisrow = ntest->argisrow;
3528 33440 : newntest->location = ntest->location;
3529 33440 : return (Node *) newntest;
3530 : }
3531 1818 : case T_BooleanTest:
3532 : {
3533 : /*
3534 : * This case could be folded into the generic handling used
3535 : * for ArrayExpr etc. But because the simplification logic is
3536 : * so trivial, applying evaluate_expr() to perform it would be
3537 : * a heavy overhead. BooleanTest is probably common enough to
3538 : * justify keeping this bespoke implementation.
3539 : */
3540 1818 : BooleanTest *btest = (BooleanTest *) node;
3541 : BooleanTest *newbtest;
3542 : Node *arg;
3543 :
3544 1818 : arg = eval_const_expressions_mutator((Node *) btest->arg,
3545 : context);
3546 1818 : if (arg && IsA(arg, Const))
3547 : {
3548 222 : Const *carg = (Const *) arg;
3549 : bool result;
3550 :
3551 222 : switch (btest->booltesttype)
3552 : {
3553 0 : case IS_TRUE:
3554 0 : result = (!carg->constisnull &&
3555 0 : DatumGetBool(carg->constvalue));
3556 0 : break;
3557 222 : case IS_NOT_TRUE:
3558 444 : result = (carg->constisnull ||
3559 222 : !DatumGetBool(carg->constvalue));
3560 222 : break;
3561 0 : case IS_FALSE:
3562 0 : result = (!carg->constisnull &&
3563 0 : !DatumGetBool(carg->constvalue));
3564 0 : break;
3565 0 : case IS_NOT_FALSE:
3566 0 : result = (carg->constisnull ||
3567 0 : DatumGetBool(carg->constvalue));
3568 0 : break;
3569 0 : case IS_UNKNOWN:
3570 0 : result = carg->constisnull;
3571 0 : break;
3572 0 : case IS_NOT_UNKNOWN:
3573 0 : result = !carg->constisnull;
3574 0 : break;
3575 0 : default:
3576 0 : elog(ERROR, "unrecognized booltesttype: %d",
3577 : (int) btest->booltesttype);
3578 : result = false; /* keep compiler quiet */
3579 : break;
3580 : }
3581 :
3582 222 : return makeBoolConst(result, false);
3583 : }
3584 :
3585 1596 : newbtest = makeNode(BooleanTest);
3586 1596 : newbtest->arg = (Expr *) arg;
3587 1596 : newbtest->booltesttype = btest->booltesttype;
3588 1596 : newbtest->location = btest->location;
3589 1596 : return (Node *) newbtest;
3590 : }
3591 23398 : case T_CoerceToDomain:
3592 : {
3593 : /*
3594 : * If the domain currently has no constraints, we replace the
3595 : * CoerceToDomain node with a simple RelabelType, which is
3596 : * both far faster to execute and more amenable to later
3597 : * optimization. We must then mark the plan as needing to be
3598 : * rebuilt if the domain's constraints change.
3599 : *
3600 : * Also, in estimation mode, always replace CoerceToDomain
3601 : * nodes, effectively assuming that the coercion will succeed.
3602 : */
3603 23398 : CoerceToDomain *cdomain = (CoerceToDomain *) node;
3604 : CoerceToDomain *newcdomain;
3605 : Node *arg;
3606 :
3607 23398 : arg = eval_const_expressions_mutator((Node *) cdomain->arg,
3608 : context);
3609 23374 : if (context->estimate ||
3610 23350 : !DomainHasConstraints(cdomain->resulttype))
3611 : {
3612 : /* Record dependency, if this isn't estimation mode */
3613 15238 : if (context->root && !context->estimate)
3614 15172 : record_plan_type_dependency(context->root,
3615 : cdomain->resulttype);
3616 :
3617 : /* Generate RelabelType to substitute for CoerceToDomain */
3618 15238 : return applyRelabelType(arg,
3619 : cdomain->resulttype,
3620 : cdomain->resulttypmod,
3621 : cdomain->resultcollid,
3622 : cdomain->coercionformat,
3623 : cdomain->location,
3624 : true);
3625 : }
3626 :
3627 8136 : newcdomain = makeNode(CoerceToDomain);
3628 8136 : newcdomain->arg = (Expr *) arg;
3629 8136 : newcdomain->resulttype = cdomain->resulttype;
3630 8136 : newcdomain->resulttypmod = cdomain->resulttypmod;
3631 8136 : newcdomain->resultcollid = cdomain->resultcollid;
3632 8136 : newcdomain->coercionformat = cdomain->coercionformat;
3633 8136 : newcdomain->location = cdomain->location;
3634 8136 : return (Node *) newcdomain;
3635 : }
3636 2556 : case T_PlaceHolderVar:
3637 :
3638 : /*
3639 : * In estimation mode, just strip the PlaceHolderVar node
3640 : * altogether; this amounts to estimating that the contained value
3641 : * won't be forced to null by an outer join. In regular mode we
3642 : * just use the default behavior (ie, simplify the expression but
3643 : * leave the PlaceHolderVar node intact).
3644 : */
3645 2556 : if (context->estimate)
3646 : {
3647 744 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
3648 :
3649 744 : return eval_const_expressions_mutator((Node *) phv->phexpr,
3650 : context);
3651 : }
3652 1812 : break;
3653 78 : case T_ConvertRowtypeExpr:
3654 : {
3655 78 : ConvertRowtypeExpr *cre = castNode(ConvertRowtypeExpr, node);
3656 : Node *arg;
3657 : ConvertRowtypeExpr *newcre;
3658 :
3659 78 : arg = eval_const_expressions_mutator((Node *) cre->arg,
3660 : context);
3661 :
3662 78 : newcre = makeNode(ConvertRowtypeExpr);
3663 78 : newcre->resulttype = cre->resulttype;
3664 78 : newcre->convertformat = cre->convertformat;
3665 78 : newcre->location = cre->location;
3666 :
3667 : /*
3668 : * In case of a nested ConvertRowtypeExpr, we can convert the
3669 : * leaf row directly to the topmost row format without any
3670 : * intermediate conversions. (This works because
3671 : * ConvertRowtypeExpr is used only for child->parent
3672 : * conversion in inheritance trees, which works by exact match
3673 : * of column name, and a column absent in an intermediate
3674 : * result can't be present in the final result.)
3675 : *
3676 : * No need to check more than one level deep, because the
3677 : * above recursion will have flattened anything else.
3678 : */
3679 78 : if (arg != NULL && IsA(arg, ConvertRowtypeExpr))
3680 : {
3681 12 : ConvertRowtypeExpr *argcre = (ConvertRowtypeExpr *) arg;
3682 :
3683 12 : arg = (Node *) argcre->arg;
3684 :
3685 : /*
3686 : * Make sure an outer implicit conversion can't hide an
3687 : * inner explicit one.
3688 : */
3689 12 : if (newcre->convertformat == COERCE_IMPLICIT_CAST)
3690 0 : newcre->convertformat = argcre->convertformat;
3691 : }
3692 :
3693 78 : newcre->arg = (Expr *) arg;
3694 :
3695 78 : if (arg != NULL && IsA(arg, Const))
3696 18 : return ece_evaluate_expr((Node *) newcre);
3697 60 : return (Node *) newcre;
3698 : }
3699 5536178 : default:
3700 5536178 : break;
3701 : }
3702 :
3703 : /*
3704 : * For any node type not handled above, copy the node unchanged but
3705 : * const-simplify its subexpressions. This is the correct thing for node
3706 : * types whose behavior might change between planning and execution, such
3707 : * as CurrentOfExpr. It's also a safe default for new node types not
3708 : * known to this routine.
3709 : */
3710 5538170 : return ece_generic_processing(node);
3711 : }
3712 :
3713 : /*
3714 : * Subroutine for eval_const_expressions: check for non-Const nodes.
3715 : *
3716 : * We can abort recursion immediately on finding a non-Const node. This is
3717 : * critical for performance, else eval_const_expressions_mutator would take
3718 : * O(N^2) time on non-simplifiable trees. However, we do need to descend
3719 : * into List nodes since expression_tree_walker sometimes invokes the walker
3720 : * function directly on List subtrees.
3721 : */
3722 : static bool
3723 176796 : contain_non_const_walker(Node *node, void *context)
3724 : {
3725 176796 : if (node == NULL)
3726 598 : return false;
3727 176198 : if (IsA(node, Const))
3728 89770 : return false;
3729 86428 : if (IsA(node, List))
3730 31182 : return expression_tree_walker(node, contain_non_const_walker, context);
3731 : /* Otherwise, abort the tree traversal and return true */
3732 55246 : return true;
3733 : }
3734 :
3735 : /*
3736 : * Subroutine for eval_const_expressions: check if a function is OK to evaluate
3737 : */
3738 : static bool
3739 230 : ece_function_is_safe(Oid funcid, eval_const_expressions_context *context)
3740 : {
3741 230 : char provolatile = func_volatile(funcid);
3742 :
3743 : /*
3744 : * Ordinarily we are only allowed to simplify immutable functions. But for
3745 : * purposes of estimation, we consider it okay to simplify functions that
3746 : * are merely stable; the risk that the result might change from planning
3747 : * time to execution time is worth taking in preference to not being able
3748 : * to estimate the value at all.
3749 : */
3750 230 : if (provolatile == PROVOLATILE_IMMUTABLE)
3751 230 : return true;
3752 0 : if (context->estimate && provolatile == PROVOLATILE_STABLE)
3753 0 : return true;
3754 0 : return false;
3755 : }
3756 :
3757 : /*
3758 : * Subroutine for eval_const_expressions: process arguments of an OR clause
3759 : *
3760 : * This includes flattening of nested ORs as well as recursion to
3761 : * eval_const_expressions to simplify the OR arguments.
3762 : *
3763 : * After simplification, OR arguments are handled as follows:
3764 : * non constant: keep
3765 : * FALSE: drop (does not affect result)
3766 : * TRUE: force result to TRUE
3767 : * NULL: keep only one
3768 : * We must keep one NULL input because OR expressions evaluate to NULL when no
3769 : * input is TRUE and at least one is NULL. We don't actually include the NULL
3770 : * here, that's supposed to be done by the caller.
3771 : *
3772 : * The output arguments *haveNull and *forceTrue must be initialized false
3773 : * by the caller. They will be set true if a NULL constant or TRUE constant,
3774 : * respectively, is detected anywhere in the argument list.
3775 : */
3776 : static List *
3777 12354 : simplify_or_arguments(List *args,
3778 : eval_const_expressions_context *context,
3779 : bool *haveNull, bool *forceTrue)
3780 : {
3781 12354 : List *newargs = NIL;
3782 : List *unprocessed_args;
3783 :
3784 : /*
3785 : * We want to ensure that any OR immediately beneath another OR gets
3786 : * flattened into a single OR-list, so as to simplify later reasoning.
3787 : *
3788 : * To avoid stack overflow from recursion of eval_const_expressions, we
3789 : * resort to some tenseness here: we keep a list of not-yet-processed
3790 : * inputs, and handle flattening of nested ORs by prepending to the to-do
3791 : * list instead of recursing. Now that the parser generates N-argument
3792 : * ORs from simple lists, this complexity is probably less necessary than
3793 : * it once was, but we might as well keep the logic.
3794 : */
3795 12354 : unprocessed_args = list_copy(args);
3796 41352 : while (unprocessed_args)
3797 : {
3798 29146 : Node *arg = (Node *) linitial(unprocessed_args);
3799 :
3800 29146 : unprocessed_args = list_delete_first(unprocessed_args);
3801 :
3802 : /* flatten nested ORs as per above comment */
3803 29146 : if (is_orclause(arg))
3804 : {
3805 6 : List *subargs = ((BoolExpr *) arg)->args;
3806 6 : List *oldlist = unprocessed_args;
3807 :
3808 6 : unprocessed_args = list_concat_copy(subargs, unprocessed_args);
3809 : /* perhaps-overly-tense code to avoid leaking old lists */
3810 6 : list_free(oldlist);
3811 6 : continue;
3812 : }
3813 :
3814 : /* If it's not an OR, simplify it */
3815 29140 : arg = eval_const_expressions_mutator(arg, context);
3816 :
3817 : /*
3818 : * It is unlikely but not impossible for simplification of a non-OR
3819 : * clause to produce an OR. Recheck, but don't be too tense about it
3820 : * since it's not a mainstream case. In particular we don't worry
3821 : * about const-simplifying the input twice, nor about list leakage.
3822 : */
3823 29140 : if (is_orclause(arg))
3824 : {
3825 0 : List *subargs = ((BoolExpr *) arg)->args;
3826 :
3827 0 : unprocessed_args = list_concat_copy(subargs, unprocessed_args);
3828 0 : continue;
3829 : }
3830 :
3831 : /*
3832 : * OK, we have a const-simplified non-OR argument. Process it per
3833 : * comments above.
3834 : */
3835 29140 : if (IsA(arg, Const))
3836 : {
3837 286 : Const *const_input = (Const *) arg;
3838 :
3839 286 : if (const_input->constisnull)
3840 48 : *haveNull = true;
3841 238 : else if (DatumGetBool(const_input->constvalue))
3842 : {
3843 148 : *forceTrue = true;
3844 :
3845 : /*
3846 : * Once we detect a TRUE result we can just exit the loop
3847 : * immediately. However, if we ever add a notion of
3848 : * non-removable functions, we'd need to keep scanning.
3849 : */
3850 148 : return NIL;
3851 : }
3852 : /* otherwise, we can drop the constant-false input */
3853 138 : continue;
3854 : }
3855 :
3856 : /* else emit the simplified arg into the result list */
3857 28854 : newargs = lappend(newargs, arg);
3858 : }
3859 :
3860 12206 : return newargs;
3861 : }
3862 :
3863 : /*
3864 : * Subroutine for eval_const_expressions: process arguments of an AND clause
3865 : *
3866 : * This includes flattening of nested ANDs as well as recursion to
3867 : * eval_const_expressions to simplify the AND arguments.
3868 : *
3869 : * After simplification, AND arguments are handled as follows:
3870 : * non constant: keep
3871 : * TRUE: drop (does not affect result)
3872 : * FALSE: force result to FALSE
3873 : * NULL: keep only one
3874 : * We must keep one NULL input because AND expressions evaluate to NULL when
3875 : * no input is FALSE and at least one is NULL. We don't actually include the
3876 : * NULL here, that's supposed to be done by the caller.
3877 : *
3878 : * The output arguments *haveNull and *forceFalse must be initialized false
3879 : * by the caller. They will be set true if a null constant or false constant,
3880 : * respectively, is detected anywhere in the argument list.
3881 : */
3882 : static List *
3883 121594 : simplify_and_arguments(List *args,
3884 : eval_const_expressions_context *context,
3885 : bool *haveNull, bool *forceFalse)
3886 : {
3887 121594 : List *newargs = NIL;
3888 : List *unprocessed_args;
3889 :
3890 : /* See comments in simplify_or_arguments */
3891 121594 : unprocessed_args = list_copy(args);
3892 448208 : while (unprocessed_args)
3893 : {
3894 328080 : Node *arg = (Node *) linitial(unprocessed_args);
3895 :
3896 328080 : unprocessed_args = list_delete_first(unprocessed_args);
3897 :
3898 : /* flatten nested ANDs as per above comment */
3899 328080 : if (is_andclause(arg))
3900 : {
3901 1120 : List *subargs = ((BoolExpr *) arg)->args;
3902 1120 : List *oldlist = unprocessed_args;
3903 :
3904 1120 : unprocessed_args = list_concat_copy(subargs, unprocessed_args);
3905 : /* perhaps-overly-tense code to avoid leaking old lists */
3906 1120 : list_free(oldlist);
3907 1120 : continue;
3908 : }
3909 :
3910 : /* If it's not an AND, simplify it */
3911 326960 : arg = eval_const_expressions_mutator(arg, context);
3912 :
3913 : /*
3914 : * It is unlikely but not impossible for simplification of a non-AND
3915 : * clause to produce an AND. Recheck, but don't be too tense about it
3916 : * since it's not a mainstream case. In particular we don't worry
3917 : * about const-simplifying the input twice, nor about list leakage.
3918 : */
3919 326960 : if (is_andclause(arg))
3920 : {
3921 30 : List *subargs = ((BoolExpr *) arg)->args;
3922 :
3923 30 : unprocessed_args = list_concat_copy(subargs, unprocessed_args);
3924 30 : continue;
3925 : }
3926 :
3927 : /*
3928 : * OK, we have a const-simplified non-AND argument. Process it per
3929 : * comments above.
3930 : */
3931 326930 : if (IsA(arg, Const))
3932 : {
3933 3144 : Const *const_input = (Const *) arg;
3934 :
3935 3144 : if (const_input->constisnull)
3936 18 : *haveNull = true;
3937 3126 : else if (!DatumGetBool(const_input->constvalue))
3938 : {
3939 1466 : *forceFalse = true;
3940 :
3941 : /*
3942 : * Once we detect a FALSE result we can just exit the loop
3943 : * immediately. However, if we ever add a notion of
3944 : * non-removable functions, we'd need to keep scanning.
3945 : */
3946 1466 : return NIL;
3947 : }
3948 : /* otherwise, we can drop the constant-true input */
3949 1678 : continue;
3950 : }
3951 :
3952 : /* else emit the simplified arg into the result list */
3953 323786 : newargs = lappend(newargs, arg);
3954 : }
3955 :
3956 120128 : return newargs;
3957 : }
3958 :
3959 : /*
3960 : * Subroutine for eval_const_expressions: try to simplify boolean equality
3961 : * or inequality condition
3962 : *
3963 : * Inputs are the operator OID and the simplified arguments to the operator.
3964 : * Returns a simplified expression if successful, or NULL if cannot
3965 : * simplify the expression.
3966 : *
3967 : * The idea here is to reduce "x = true" to "x" and "x = false" to "NOT x",
3968 : * or similarly "x <> true" to "NOT x" and "x <> false" to "x".
3969 : * This is only marginally useful in itself, but doing it in constant folding
3970 : * ensures that we will recognize these forms as being equivalent in, for
3971 : * example, partial index matching.
3972 : *
3973 : * We come here only if simplify_function has failed; therefore we cannot
3974 : * see two constant inputs, nor a constant-NULL input.
3975 : */
3976 : static Node *
3977 570 : simplify_boolean_equality(Oid opno, List *args)
3978 : {
3979 : Node *leftop;
3980 : Node *rightop;
3981 :
3982 : Assert(list_length(args) == 2);
3983 570 : leftop = linitial(args);
3984 570 : rightop = lsecond(args);
3985 570 : if (leftop && IsA(leftop, Const))
3986 : {
3987 : Assert(!((Const *) leftop)->constisnull);
3988 0 : if (opno == BooleanEqualOperator)
3989 : {
3990 0 : if (DatumGetBool(((Const *) leftop)->constvalue))
3991 0 : return rightop; /* true = foo */
3992 : else
3993 0 : return negate_clause(rightop); /* false = foo */
3994 : }
3995 : else
3996 : {
3997 0 : if (DatumGetBool(((Const *) leftop)->constvalue))
3998 0 : return negate_clause(rightop); /* true <> foo */
3999 : else
4000 0 : return rightop; /* false <> foo */
4001 : }
4002 : }
4003 570 : if (rightop && IsA(rightop, Const))
4004 : {
4005 : Assert(!((Const *) rightop)->constisnull);
4006 392 : if (opno == BooleanEqualOperator)
4007 : {
4008 326 : if (DatumGetBool(((Const *) rightop)->constvalue))
4009 164 : return leftop; /* foo = true */
4010 : else
4011 162 : return negate_clause(leftop); /* foo = false */
4012 : }
4013 : else
4014 : {
4015 66 : if (DatumGetBool(((Const *) rightop)->constvalue))
4016 60 : return negate_clause(leftop); /* foo <> true */
4017 : else
4018 6 : return leftop; /* foo <> false */
4019 : }
4020 : }
4021 178 : return NULL;
4022 : }
4023 :
4024 : /*
4025 : * Subroutine for eval_const_expressions: try to simplify a function call
4026 : * (which might originally have been an operator; we don't care)
4027 : *
4028 : * Inputs are the function OID, actual result type OID (which is needed for
4029 : * polymorphic functions), result typmod, result collation, the input
4030 : * collation to use for the function, the original argument list (not
4031 : * const-simplified yet, unless process_args is false), and some flags;
4032 : * also the context data for eval_const_expressions.
4033 : *
4034 : * Returns a simplified expression if successful, or NULL if cannot
4035 : * simplify the function call.
4036 : *
4037 : * This function is also responsible for converting named-notation argument
4038 : * lists into positional notation and/or adding any needed default argument
4039 : * expressions; which is a bit grotty, but it avoids extra fetches of the
4040 : * function's pg_proc tuple. For this reason, the args list is
4041 : * pass-by-reference. Conversion and const-simplification of the args list
4042 : * will be done even if simplification of the function call itself is not
4043 : * possible.
4044 : */
4045 : static Expr *
4046 1154650 : simplify_function(Oid funcid, Oid result_type, int32 result_typmod,
4047 : Oid result_collid, Oid input_collid, List **args_p,
4048 : bool funcvariadic, bool process_args, bool allow_non_const,
4049 : eval_const_expressions_context *context)
4050 : {
4051 1154650 : List *args = *args_p;
4052 : HeapTuple func_tuple;
4053 : Form_pg_proc func_form;
4054 : Expr *newexpr;
4055 :
4056 : /*
4057 : * We have three strategies for simplification: execute the function to
4058 : * deliver a constant result, use a transform function to generate a
4059 : * substitute node tree, or expand in-line the body of the function
4060 : * definition (which only works for simple SQL-language functions, but
4061 : * that is a common case). Each case needs access to the function's
4062 : * pg_proc tuple, so fetch it just once.
4063 : *
4064 : * Note: the allow_non_const flag suppresses both the second and third
4065 : * strategies; so if !allow_non_const, simplify_function can only return a
4066 : * Const or NULL. Argument-list rewriting happens anyway, though.
4067 : */
4068 1154650 : func_tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
4069 1154650 : if (!HeapTupleIsValid(func_tuple))
4070 0 : elog(ERROR, "cache lookup failed for function %u", funcid);
4071 1154650 : func_form = (Form_pg_proc) GETSTRUCT(func_tuple);
4072 :
4073 : /*
4074 : * Process the function arguments, unless the caller did it already.
4075 : *
4076 : * Here we must deal with named or defaulted arguments, and then
4077 : * recursively apply eval_const_expressions to the whole argument list.
4078 : */
4079 1154650 : if (process_args)
4080 : {
4081 1152580 : args = expand_function_arguments(args, false, result_type, func_tuple);
4082 1152580 : args = (List *) expression_tree_mutator((Node *) args,
4083 : eval_const_expressions_mutator,
4084 : (void *) context);
4085 : /* Argument processing done, give it back to the caller */
4086 1152484 : *args_p = args;
4087 : }
4088 :
4089 : /* Now attempt simplification of the function call proper. */
4090 :
4091 1154554 : newexpr = evaluate_function(funcid, result_type, result_typmod,
4092 : result_collid, input_collid,
4093 : args, funcvariadic,
4094 : func_tuple, context);
4095 :
4096 1151042 : if (!newexpr && allow_non_const && OidIsValid(func_form->prosupport))
4097 : {
4098 : /*
4099 : * Build a SupportRequestSimplify node to pass to the support
4100 : * function, pointing to a dummy FuncExpr node containing the
4101 : * simplified arg list. We use this approach to present a uniform
4102 : * interface to the support function regardless of how the target
4103 : * function is actually being invoked.
4104 : */
4105 : SupportRequestSimplify req;
4106 : FuncExpr fexpr;
4107 :
4108 28254 : fexpr.xpr.type = T_FuncExpr;
4109 28254 : fexpr.funcid = funcid;
4110 28254 : fexpr.funcresulttype = result_type;
4111 28254 : fexpr.funcretset = func_form->proretset;
4112 28254 : fexpr.funcvariadic = funcvariadic;
4113 28254 : fexpr.funcformat = COERCE_EXPLICIT_CALL;
4114 28254 : fexpr.funccollid = result_collid;
4115 28254 : fexpr.inputcollid = input_collid;
4116 28254 : fexpr.args = args;
4117 28254 : fexpr.location = -1;
4118 :
4119 28254 : req.type = T_SupportRequestSimplify;
4120 28254 : req.root = context->root;
4121 28254 : req.fcall = &fexpr;
4122 :
4123 : newexpr = (Expr *)
4124 28254 : DatumGetPointer(OidFunctionCall1(func_form->prosupport,
4125 : PointerGetDatum(&req)));
4126 :
4127 : /* catch a possible API misunderstanding */
4128 : Assert(newexpr != (Expr *) &fexpr);
4129 : }
4130 :
4131 1151042 : if (!newexpr && allow_non_const)
4132 980610 : newexpr = inline_function(funcid, result_type, result_collid,
4133 : input_collid, args, funcvariadic,
4134 : func_tuple, context);
4135 :
4136 1151022 : ReleaseSysCache(func_tuple);
4137 :
4138 1151022 : return newexpr;
4139 : }
4140 :
4141 : /*
4142 : * expand_function_arguments: convert named-notation args to positional args
4143 : * and/or insert default args, as needed
4144 : *
4145 : * Returns a possibly-transformed version of the args list.
4146 : *
4147 : * If include_out_arguments is true, then the args list and the result
4148 : * include OUT arguments.
4149 : *
4150 : * The expected result type of the call must be given, for sanity-checking
4151 : * purposes. Also, we ask the caller to provide the function's actual
4152 : * pg_proc tuple, not just its OID.
4153 : *
4154 : * If we need to change anything, the input argument list is copied, not
4155 : * modified.
4156 : *
4157 : * Note: this gets applied to operator argument lists too, even though the
4158 : * cases it handles should never occur there. This should be OK since it
4159 : * will fall through very quickly if there's nothing to do.
4160 : */
4161 : List *
4162 1156286 : expand_function_arguments(List *args, bool include_out_arguments,
4163 : Oid result_type, HeapTuple func_tuple)
4164 : {
4165 1156286 : Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
4166 1156286 : Oid *proargtypes = funcform->proargtypes.values;
4167 1156286 : int pronargs = funcform->pronargs;
4168 1156286 : bool has_named_args = false;
4169 : ListCell *lc;
4170 :
4171 : /*
4172 : * If we are asked to match to OUT arguments, then use the proallargtypes
4173 : * array (which includes those); otherwise use proargtypes (which
4174 : * doesn't). Of course, if proallargtypes is null, we always use
4175 : * proargtypes. (Fetching proallargtypes is annoyingly expensive
4176 : * considering that we may have nothing to do here, but fortunately the
4177 : * common case is include_out_arguments == false.)
4178 : */
4179 1156286 : if (include_out_arguments)
4180 : {
4181 : Datum proallargtypes;
4182 : bool isNull;
4183 :
4184 416 : proallargtypes = SysCacheGetAttr(PROCOID, func_tuple,
4185 : Anum_pg_proc_proallargtypes,
4186 : &isNull);
4187 416 : if (!isNull)
4188 : {
4189 162 : ArrayType *arr = DatumGetArrayTypeP(proallargtypes);
4190 :
4191 162 : pronargs = ARR_DIMS(arr)[0];
4192 162 : if (ARR_NDIM(arr) != 1 ||
4193 162 : pronargs < 0 ||
4194 162 : ARR_HASNULL(arr) ||
4195 162 : ARR_ELEMTYPE(arr) != OIDOID)
4196 0 : elog(ERROR, "proallargtypes is not a 1-D Oid array or it contains nulls");
4197 : Assert(pronargs >= funcform->pronargs);
4198 162 : proargtypes = (Oid *) ARR_DATA_PTR(arr);
4199 : }
4200 : }
4201 :
4202 : /* Do we have any named arguments? */
4203 3036254 : foreach(lc, args)
4204 : {
4205 1895822 : Node *arg = (Node *) lfirst(lc);
4206 :
4207 1895822 : if (IsA(arg, NamedArgExpr))
4208 : {
4209 15854 : has_named_args = true;
4210 15854 : break;
4211 : }
4212 : }
4213 :
4214 : /* If so, we must apply reorder_function_arguments */
4215 1156286 : if (has_named_args)
4216 : {
4217 15854 : args = reorder_function_arguments(args, pronargs, func_tuple);
4218 : /* Recheck argument types and add casts if needed */
4219 15854 : recheck_cast_function_args(args, result_type,
4220 : proargtypes, pronargs,
4221 : func_tuple);
4222 : }
4223 1140432 : else if (list_length(args) < pronargs)
4224 : {
4225 : /* No named args, but we seem to be short some defaults */
4226 5788 : args = add_function_defaults(args, pronargs, func_tuple);
4227 : /* Recheck argument types and add casts if needed */
4228 5788 : recheck_cast_function_args(args, result_type,
4229 : proargtypes, pronargs,
4230 : func_tuple);
4231 : }
4232 :
4233 1156286 : return args;
4234 : }
4235 :
4236 : /*
4237 : * reorder_function_arguments: convert named-notation args to positional args
4238 : *
4239 : * This function also inserts default argument values as needed, since it's
4240 : * impossible to form a truly valid positional call without that.
4241 : */
4242 : static List *
4243 15854 : reorder_function_arguments(List *args, int pronargs, HeapTuple func_tuple)
4244 : {
4245 15854 : Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
4246 15854 : int nargsprovided = list_length(args);
4247 : Node *argarray[FUNC_MAX_ARGS];
4248 : ListCell *lc;
4249 : int i;
4250 :
4251 : Assert(nargsprovided <= pronargs);
4252 15854 : if (pronargs < 0 || pronargs > FUNC_MAX_ARGS)
4253 0 : elog(ERROR, "too many function arguments");
4254 15854 : memset(argarray, 0, pronargs * sizeof(Node *));
4255 :
4256 : /* Deconstruct the argument list into an array indexed by argnumber */
4257 15854 : i = 0;
4258 64398 : foreach(lc, args)
4259 : {
4260 48544 : Node *arg = (Node *) lfirst(lc);
4261 :
4262 48544 : if (!IsA(arg, NamedArgExpr))
4263 : {
4264 : /* positional argument, assumed to precede all named args */
4265 : Assert(argarray[i] == NULL);
4266 1850 : argarray[i++] = arg;
4267 : }
4268 : else
4269 : {
4270 46694 : NamedArgExpr *na = (NamedArgExpr *) arg;
4271 :
4272 : Assert(na->argnumber >= 0 && na->argnumber < pronargs);
4273 : Assert(argarray[na->argnumber] == NULL);
4274 46694 : argarray[na->argnumber] = (Node *) na->arg;
4275 : }
4276 : }
4277 :
4278 : /*
4279 : * Fetch default expressions, if needed, and insert into array at proper
4280 : * locations (they aren't necessarily consecutive or all used)
4281 : */
4282 15854 : if (nargsprovided < pronargs)
4283 : {
4284 7290 : List *defaults = fetch_function_defaults(func_tuple);
4285 :
4286 7290 : i = pronargs - funcform->pronargdefaults;
4287 41778 : foreach(lc, defaults)
4288 : {
4289 34488 : if (argarray[i] == NULL)
4290 14456 : argarray[i] = (Node *) lfirst(lc);
4291 34488 : i++;
4292 : }
4293 : }
4294 :
4295 : /* Now reconstruct the args list in proper order */
4296 15854 : args = NIL;
4297 78854 : for (i = 0; i < pronargs; i++)
4298 : {
4299 : Assert(argarray[i] != NULL);
4300 63000 : args = lappend(args, argarray[i]);
4301 : }
4302 :
4303 15854 : return args;
4304 : }
4305 :
4306 : /*
4307 : * add_function_defaults: add missing function arguments from its defaults
4308 : *
4309 : * This is used only when the argument list was positional to begin with,
4310 : * and so we know we just need to add defaults at the end.
4311 : */
4312 : static List *
4313 5788 : add_function_defaults(List *args, int pronargs, HeapTuple func_tuple)
4314 : {
4315 5788 : int nargsprovided = list_length(args);
4316 : List *defaults;
4317 : int ndelete;
4318 :
4319 : /* Get all the default expressions from the pg_proc tuple */
4320 5788 : defaults = fetch_function_defaults(func_tuple);
4321 :
4322 : /* Delete any unused defaults from the list */
4323 5788 : ndelete = nargsprovided + list_length(defaults) - pronargs;
4324 5788 : if (ndelete < 0)
4325 0 : elog(ERROR, "not enough default arguments");
4326 5788 : if (ndelete > 0)
4327 228 : defaults = list_delete_first_n(defaults, ndelete);
4328 :
4329 : /* And form the combined argument list, not modifying the input list */
4330 5788 : return list_concat_copy(args, defaults);
4331 : }
4332 :
4333 : /*
4334 : * fetch_function_defaults: get function's default arguments as expression list
4335 : */
4336 : static List *
4337 13078 : fetch_function_defaults(HeapTuple func_tuple)
4338 : {
4339 : List *defaults;
4340 : Datum proargdefaults;
4341 : char *str;
4342 :
4343 13078 : proargdefaults = SysCacheGetAttrNotNull(PROCOID, func_tuple,
4344 : Anum_pg_proc_proargdefaults);
4345 13078 : str = TextDatumGetCString(proargdefaults);
4346 13078 : defaults = castNode(List, stringToNode(str));
4347 13078 : pfree(str);
4348 13078 : return defaults;
4349 : }
4350 :
4351 : /*
4352 : * recheck_cast_function_args: recheck function args and typecast as needed
4353 : * after adding defaults.
4354 : *
4355 : * It is possible for some of the defaulted arguments to be polymorphic;
4356 : * therefore we can't assume that the default expressions have the correct
4357 : * data types already. We have to re-resolve polymorphics and do coercion
4358 : * just like the parser did.
4359 : *
4360 : * This should be a no-op if there are no polymorphic arguments,
4361 : * but we do it anyway to be sure.
4362 : *
4363 : * Note: if any casts are needed, the args list is modified in-place;
4364 : * caller should have already copied the list structure.
4365 : */
4366 : static void
4367 21642 : recheck_cast_function_args(List *args, Oid result_type,
4368 : Oid *proargtypes, int pronargs,
4369 : HeapTuple func_tuple)
4370 : {
4371 21642 : Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
4372 : int nargs;
4373 : Oid actual_arg_types[FUNC_MAX_ARGS];
4374 : Oid declared_arg_types[FUNC_MAX_ARGS];
4375 : Oid rettype;
4376 : ListCell *lc;
4377 :
4378 21642 : if (list_length(args) > FUNC_MAX_ARGS)
4379 0 : elog(ERROR, "too many function arguments");
4380 21642 : nargs = 0;
4381 106446 : foreach(lc, args)
4382 : {
4383 84804 : actual_arg_types[nargs++] = exprType((Node *) lfirst(lc));
4384 : }
4385 : Assert(nargs == pronargs);
4386 21642 : memcpy(declared_arg_types, proargtypes, pronargs * sizeof(Oid));
4387 21642 : rettype = enforce_generic_type_consistency(actual_arg_types,
4388 : declared_arg_types,
4389 : nargs,
4390 : funcform->prorettype,
4391 : false);
4392 : /* let's just check we got the same answer as the parser did ... */
4393 21642 : if (rettype != result_type)
4394 0 : elog(ERROR, "function's resolved result type changed during planning");
4395 :
4396 : /* perform any necessary typecasting of arguments */
4397 21642 : make_fn_arguments(NULL, args, actual_arg_types, declared_arg_types);
4398 21642 : }
4399 :
4400 : /*
4401 : * evaluate_function: try to pre-evaluate a function call
4402 : *
4403 : * We can do this if the function is strict and has any constant-null inputs
4404 : * (just return a null constant), or if the function is immutable and has all
4405 : * constant inputs (call it and return the result as a Const node). In
4406 : * estimation mode we are willing to pre-evaluate stable functions too.
4407 : *
4408 : * Returns a simplified expression if successful, or NULL if cannot
4409 : * simplify the function.
4410 : */
4411 : static Expr *
4412 1154554 : evaluate_function(Oid funcid, Oid result_type, int32 result_typmod,
4413 : Oid result_collid, Oid input_collid, List *args,
4414 : bool funcvariadic,
4415 : HeapTuple func_tuple,
4416 : eval_const_expressions_context *context)
4417 : {
4418 1154554 : Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
4419 1154554 : bool has_nonconst_input = false;
4420 1154554 : bool has_null_input = false;
4421 : ListCell *arg;
4422 : FuncExpr *newexpr;
4423 :
4424 : /*
4425 : * Can't simplify if it returns a set.
4426 : */
4427 1154554 : if (funcform->proretset)
4428 53054 : return NULL;
4429 :
4430 : /*
4431 : * Can't simplify if it returns RECORD. The immediate problem is that it
4432 : * will be needing an expected tupdesc which we can't supply here.
4433 : *
4434 : * In the case where it has OUT parameters, we could build an expected
4435 : * tupdesc from those, but there may be other gotchas lurking. In
4436 : * particular, if the function were to return NULL, we would produce a
4437 : * null constant with no remaining indication of which concrete record
4438 : * type it is. For now, seems best to leave the function call unreduced.
4439 : */
4440 1101500 : if (funcform->prorettype == RECORDOID)
4441 3850 : return NULL;
4442 :
4443 : /*
4444 : * Check for constant inputs and especially constant-NULL inputs.
4445 : */
4446 2898074 : foreach(arg, args)
4447 : {
4448 1800424 : if (IsA(lfirst(arg), Const))
4449 766836 : has_null_input |= ((Const *) lfirst(arg))->constisnull;
4450 : else
4451 1033588 : has_nonconst_input = true;
4452 : }
4453 :
4454 : /*
4455 : * If the function is strict and has a constant-NULL input, it will never
4456 : * be called at all, so we can replace the call by a NULL constant, even
4457 : * if there are other inputs that aren't constant, and even if the
4458 : * function is not otherwise immutable.
4459 : */
4460 1097650 : if (funcform->proisstrict && has_null_input)
4461 640 : return (Expr *) makeNullConst(result_type, result_typmod,
4462 : result_collid);
4463 :
4464 : /*
4465 : * Otherwise, can simplify only if all inputs are constants. (For a
4466 : * non-strict function, constant NULL inputs are treated the same as
4467 : * constant non-NULL inputs.)
4468 : */
4469 1097010 : if (has_nonconst_input)
4470 774266 : return NULL;
4471 :
4472 : /*
4473 : * Ordinarily we are only allowed to simplify immutable functions. But for
4474 : * purposes of estimation, we consider it okay to simplify functions that
4475 : * are merely stable; the risk that the result might change from planning
4476 : * time to execution time is worth taking in preference to not being able
4477 : * to estimate the value at all.
4478 : */
4479 322744 : if (funcform->provolatile == PROVOLATILE_IMMUTABLE)
4480 : /* okay */ ;
4481 151116 : else if (context->estimate && funcform->provolatile == PROVOLATILE_STABLE)
4482 : /* okay */ ;
4483 : else
4484 149566 : return NULL;
4485 :
4486 : /*
4487 : * OK, looks like we can simplify this operator/function.
4488 : *
4489 : * Build a new FuncExpr node containing the already-simplified arguments.
4490 : */
4491 173178 : newexpr = makeNode(FuncExpr);
4492 173178 : newexpr->funcid = funcid;
4493 173178 : newexpr->funcresulttype = result_type;
4494 173178 : newexpr->funcretset = false;
4495 173178 : newexpr->funcvariadic = funcvariadic;
4496 173178 : newexpr->funcformat = COERCE_EXPLICIT_CALL; /* doesn't matter */
4497 173178 : newexpr->funccollid = result_collid; /* doesn't matter */
4498 173178 : newexpr->inputcollid = input_collid;
4499 173178 : newexpr->args = args;
4500 173178 : newexpr->location = -1;
4501 :
4502 173178 : return evaluate_expr((Expr *) newexpr, result_type, result_typmod,
4503 : result_collid);
4504 : }
4505 :
4506 : /*
4507 : * inline_function: try to expand a function call inline
4508 : *
4509 : * If the function is a sufficiently simple SQL-language function
4510 : * (just "SELECT expression"), then we can inline it and avoid the rather
4511 : * high per-call overhead of SQL functions. Furthermore, this can expose
4512 : * opportunities for constant-folding within the function expression.
4513 : *
4514 : * We have to beware of some special cases however. A directly or
4515 : * indirectly recursive function would cause us to recurse forever,
4516 : * so we keep track of which functions we are already expanding and
4517 : * do not re-expand them. Also, if a parameter is used more than once
4518 : * in the SQL-function body, we require it not to contain any volatile
4519 : * functions (volatiles might deliver inconsistent answers) nor to be
4520 : * unreasonably expensive to evaluate. The expensiveness check not only
4521 : * prevents us from doing multiple evaluations of an expensive parameter
4522 : * at runtime, but is a safety value to limit growth of an expression due
4523 : * to repeated inlining.
4524 : *
4525 : * We must also beware of changing the volatility or strictness status of
4526 : * functions by inlining them.
4527 : *
4528 : * Also, at the moment we can't inline functions returning RECORD. This
4529 : * doesn't work in the general case because it discards information such
4530 : * as OUT-parameter declarations.
4531 : *
4532 : * Also, context-dependent expression nodes in the argument list are trouble.
4533 : *
4534 : * Returns a simplified expression if successful, or NULL if cannot
4535 : * simplify the function.
4536 : */
4537 : static Expr *
4538 980610 : inline_function(Oid funcid, Oid result_type, Oid result_collid,
4539 : Oid input_collid, List *args,
4540 : bool funcvariadic,
4541 : HeapTuple func_tuple,
4542 : eval_const_expressions_context *context)
4543 : {
4544 980610 : Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
4545 : char *src;
4546 : Datum tmp;
4547 : bool isNull;
4548 : MemoryContext oldcxt;
4549 : MemoryContext mycxt;
4550 : inline_error_callback_arg callback_arg;
4551 : ErrorContextCallback sqlerrcontext;
4552 : FuncExpr *fexpr;
4553 : SQLFunctionParseInfoPtr pinfo;
4554 : TupleDesc rettupdesc;
4555 : ParseState *pstate;
4556 : List *raw_parsetree_list;
4557 : List *querytree_list;
4558 : Query *querytree;
4559 : Node *newexpr;
4560 : int *usecounts;
4561 : ListCell *arg;
4562 : int i;
4563 :
4564 : /*
4565 : * Forget it if the function is not SQL-language or has other showstopper
4566 : * properties. (The prokind and nargs checks are just paranoia.)
4567 : */
4568 980610 : if (funcform->prolang != SQLlanguageId ||
4569 32598 : funcform->prokind != PROKIND_FUNCTION ||
4570 32598 : funcform->prosecdef ||
4571 32586 : funcform->proretset ||
4572 31250 : funcform->prorettype == RECORDOID ||
4573 61870 : !heap_attisnull(func_tuple, Anum_pg_proc_proconfig, NULL) ||
4574 30926 : funcform->pronargs != list_length(args))
4575 949684 : return NULL;
4576 :
4577 : /* Check for recursive function, and give up trying to expand if so */
4578 30926 : if (list_member_oid(context->active_fns, funcid))
4579 8508 : return NULL;
4580 :
4581 : /* Check permission to call function (fail later, if not) */
4582 22418 : if (object_aclcheck(ProcedureRelationId, funcid, GetUserId(), ACL_EXECUTE) != ACLCHECK_OK)
4583 14 : return NULL;
4584 :
4585 : /* Check whether a plugin wants to hook function entry/exit */
4586 22404 : if (FmgrHookIsNeeded(funcid))
4587 0 : return NULL;
4588 :
4589 : /*
4590 : * Make a temporary memory context, so that we don't leak all the stuff
4591 : * that parsing might create.
4592 : */
4593 22404 : mycxt = AllocSetContextCreate(CurrentMemoryContext,
4594 : "inline_function",
4595 : ALLOCSET_DEFAULT_SIZES);
4596 22404 : oldcxt = MemoryContextSwitchTo(mycxt);
4597 :
4598 : /*
4599 : * We need a dummy FuncExpr node containing the already-simplified
4600 : * arguments. (In some cases we don't really need it, but building it is
4601 : * cheap enough that it's not worth contortions to avoid.)
4602 : */
4603 22404 : fexpr = makeNode(FuncExpr);
4604 22404 : fexpr->funcid = funcid;
4605 22404 : fexpr->funcresulttype = result_type;
4606 22404 : fexpr->funcretset = false;
4607 22404 : fexpr->funcvariadic = funcvariadic;
4608 22404 : fexpr->funcformat = COERCE_EXPLICIT_CALL; /* doesn't matter */
4609 22404 : fexpr->funccollid = result_collid; /* doesn't matter */
4610 22404 : fexpr->inputcollid = input_collid;
4611 22404 : fexpr->args = args;
4612 22404 : fexpr->location = -1;
4613 :
4614 : /* Fetch the function body */
4615 22404 : tmp = SysCacheGetAttrNotNull(PROCOID, func_tuple, Anum_pg_proc_prosrc);
4616 22404 : src = TextDatumGetCString(tmp);
4617 :
4618 : /*
4619 : * Setup error traceback support for ereport(). This is so that we can
4620 : * finger the function that bad information came from.
4621 : */
4622 22404 : callback_arg.proname = NameStr(funcform->proname);
4623 22404 : callback_arg.prosrc = src;
4624 :
4625 22404 : sqlerrcontext.callback = sql_inline_error_callback;
4626 22404 : sqlerrcontext.arg = (void *) &callback_arg;
4627 22404 : sqlerrcontext.previous = error_context_stack;
4628 22404 : error_context_stack = &sqlerrcontext;
4629 :
4630 : /* If we have prosqlbody, pay attention to that not prosrc */
4631 22404 : tmp = SysCacheGetAttr(PROCOID,
4632 : func_tuple,
4633 : Anum_pg_proc_prosqlbody,
4634 : &isNull);
4635 22404 : if (!isNull)
4636 : {
4637 : Node *n;
4638 : List *query_list;
4639 :
4640 2944 : n = stringToNode(TextDatumGetCString(tmp));
4641 2944 : if (IsA(n, List))
4642 2158 : query_list = linitial_node(List, castNode(List, n));
4643 : else
4644 786 : query_list = list_make1(n);
4645 2944 : if (list_length(query_list) != 1)
4646 6 : goto fail;
4647 2938 : querytree = linitial(query_list);
4648 :
4649 : /*
4650 : * Because we'll insist below that the querytree have an empty rtable
4651 : * and no sublinks, it cannot have any relation references that need
4652 : * to be locked or rewritten. So we can omit those steps.
4653 : */
4654 : }
4655 : else
4656 : {
4657 : /* Set up to handle parameters while parsing the function body. */
4658 19460 : pinfo = prepare_sql_fn_parse_info(func_tuple,
4659 : (Node *) fexpr,
4660 : input_collid);
4661 :
4662 : /*
4663 : * We just do parsing and parse analysis, not rewriting, because
4664 : * rewriting will not affect table-free-SELECT-only queries, which is
4665 : * all that we care about. Also, we can punt as soon as we detect
4666 : * more than one command in the function body.
4667 : */
4668 19460 : raw_parsetree_list = pg_parse_query(src);
4669 19460 : if (list_length(raw_parsetree_list) != 1)
4670 74 : goto fail;
4671 :
4672 19386 : pstate = make_parsestate(NULL);
4673 19386 : pstate->p_sourcetext = src;
4674 19386 : sql_fn_parser_setup(pstate, pinfo);
4675 :
4676 19386 : querytree = transformTopLevelStmt(pstate, linitial(raw_parsetree_list));
4677 :
4678 19374 : free_parsestate(pstate);
4679 : }
4680 :
4681 : /*
4682 : * The single command must be a simple "SELECT expression".
4683 : *
4684 : * Note: if you change the tests involved in this, see also plpgsql's
4685 : * exec_simple_check_plan(). That generally needs to have the same idea
4686 : * of what's a "simple expression", so that inlining a function that
4687 : * previously wasn't inlined won't change plpgsql's conclusion.
4688 : */
4689 22312 : if (!IsA(querytree, Query) ||
4690 22312 : querytree->commandType != CMD_SELECT ||
4691 22182 : querytree->hasAggs ||
4692 22106 : querytree->hasWindowFuncs ||
4693 22106 : querytree->hasTargetSRFs ||
4694 22106 : querytree->hasSubLinks ||
4695 21474 : querytree->cteList ||
4696 21474 : querytree->rtable ||
4697 19852 : querytree->jointree->fromlist ||
4698 19852 : querytree->jointree->quals ||
4699 19852 : querytree->groupClause ||
4700 19852 : querytree->groupingSets ||
4701 19852 : querytree->havingQual ||
4702 19852 : querytree->windowClause ||
4703 19852 : querytree->distinctClause ||
4704 19852 : querytree->sortClause ||
4705 19852 : querytree->limitOffset ||
4706 19852 : querytree->limitCount ||
4707 39560 : querytree->setOperations ||
4708 19780 : list_length(querytree->targetList) != 1)
4709 2592 : goto fail;
4710 :
4711 : /* If the function result is composite, resolve it */
4712 19720 : (void) get_expr_result_type((Node *) fexpr,
4713 : NULL,
4714 : &rettupdesc);
4715 :
4716 : /*
4717 : * Make sure the function (still) returns what it's declared to. This
4718 : * will raise an error if wrong, but that's okay since the function would
4719 : * fail at runtime anyway. Note that check_sql_fn_retval will also insert
4720 : * a coercion if needed to make the tlist expression match the declared
4721 : * type of the function.
4722 : *
4723 : * Note: we do not try this until we have verified that no rewriting was
4724 : * needed; that's probably not important, but let's be careful.
4725 : */
4726 19720 : querytree_list = list_make1(querytree);
4727 19720 : if (check_sql_fn_retval(list_make1(querytree_list),
4728 : result_type, rettupdesc,
4729 19720 : funcform->prokind,
4730 : false, NULL))
4731 12 : goto fail; /* reject whole-tuple-result cases */
4732 :
4733 : /*
4734 : * Given the tests above, check_sql_fn_retval shouldn't have decided to
4735 : * inject a projection step, but let's just make sure.
4736 : */
4737 19702 : if (querytree != linitial(querytree_list))
4738 0 : goto fail;
4739 :
4740 : /* Now we can grab the tlist expression */
4741 19702 : newexpr = (Node *) ((TargetEntry *) linitial(querytree->targetList))->expr;
4742 :
4743 : /*
4744 : * If the SQL function returns VOID, we can only inline it if it is a
4745 : * SELECT of an expression returning VOID (ie, it's just a redirection to
4746 : * another VOID-returning function). In all non-VOID-returning cases,
4747 : * check_sql_fn_retval should ensure that newexpr returns the function's
4748 : * declared result type, so this test shouldn't fail otherwise; but we may
4749 : * as well cope gracefully if it does.
4750 : */
4751 19702 : if (exprType(newexpr) != result_type)
4752 18 : goto fail;
4753 :
4754 : /*
4755 : * Additional validity checks on the expression. It mustn't be more
4756 : * volatile than the surrounding function (this is to avoid breaking hacks
4757 : * that involve pretending a function is immutable when it really ain't).
4758 : * If the surrounding function is declared strict, then the expression
4759 : * must contain only strict constructs and must use all of the function
4760 : * parameters (this is overkill, but an exact analysis is hard).
4761 : */
4762 20446 : if (funcform->provolatile == PROVOLATILE_IMMUTABLE &&
4763 762 : contain_mutable_functions(newexpr))
4764 12 : goto fail;
4765 20518 : else if (funcform->provolatile == PROVOLATILE_STABLE &&
4766 846 : contain_volatile_functions(newexpr))
4767 0 : goto fail;
4768 :
4769 21308 : if (funcform->proisstrict &&
4770 1636 : contain_nonstrict_functions(newexpr))
4771 172 : goto fail;
4772 :
4773 : /*
4774 : * If any parameter expression contains a context-dependent node, we can't
4775 : * inline, for fear of putting such a node into the wrong context.
4776 : */
4777 19500 : if (contain_context_dependent_node((Node *) args))
4778 6 : goto fail;
4779 :
4780 : /*
4781 : * We may be able to do it; there are still checks on parameter usage to
4782 : * make, but those are most easily done in combination with the actual
4783 : * substitution of the inputs. So start building expression with inputs
4784 : * substituted.
4785 : */
4786 19494 : usecounts = (int *) palloc0(funcform->pronargs * sizeof(int));
4787 19494 : newexpr = substitute_actual_parameters(newexpr, funcform->pronargs,
4788 : args, usecounts);
4789 :
4790 : /* Now check for parameter usage */
4791 19494 : i = 0;
4792 40432 : foreach(arg, args)
4793 : {
4794 20938 : Node *param = lfirst(arg);
4795 :
4796 20938 : if (usecounts[i] == 0)
4797 : {
4798 : /* Param not used at all: uncool if func is strict */
4799 164 : if (funcform->proisstrict)
4800 0 : goto fail;
4801 : }
4802 20774 : else if (usecounts[i] != 1)
4803 : {
4804 : /* Param used multiple times: uncool if expensive or volatile */
4805 : QualCost eval_cost;
4806 :
4807 : /*
4808 : * We define "expensive" as "contains any subplan or more than 10
4809 : * operators". Note that the subplan search has to be done
4810 : * explicitly, since cost_qual_eval() will barf on unplanned
4811 : * subselects.
4812 : */
4813 16454 : if (contain_subplans(param))
4814 0 : goto fail;
4815 16454 : cost_qual_eval(&eval_cost, list_make1(param), NULL);
4816 16454 : if (eval_cost.startup + eval_cost.per_tuple >
4817 16454 : 10 * cpu_operator_cost)
4818 0 : goto fail;
4819 :
4820 : /*
4821 : * Check volatility last since this is more expensive than the
4822 : * above tests
4823 : */
4824 16454 : if (contain_volatile_functions(param))
4825 0 : goto fail;
4826 : }
4827 20938 : i++;
4828 : }
4829 :
4830 : /*
4831 : * Whew --- we can make the substitution. Copy the modified expression
4832 : * out of the temporary memory context, and clean up.
4833 : */
4834 19494 : MemoryContextSwitchTo(oldcxt);
4835 :
4836 19494 : newexpr = copyObject(newexpr);
4837 :
4838 19494 : MemoryContextDelete(mycxt);
4839 :
4840 : /*
4841 : * If the result is of a collatable type, force the result to expose the
4842 : * correct collation. In most cases this does not matter, but it's
4843 : * possible that the function result is used directly as a sort key or in
4844 : * other places where we expect exprCollation() to tell the truth.
4845 : */
4846 19494 : if (OidIsValid(result_collid))
4847 : {
4848 1358 : Oid exprcoll = exprCollation(newexpr);
4849 :
4850 1358 : if (OidIsValid(exprcoll) && exprcoll != result_collid)
4851 : {
4852 36 : CollateExpr *newnode = makeNode(CollateExpr);
4853 :
4854 36 : newnode->arg = (Expr *) newexpr;
4855 36 : newnode->collOid = result_collid;
4856 36 : newnode->location = -1;
4857 :
4858 36 : newexpr = (Node *) newnode;
4859 : }
4860 : }
4861 :
4862 : /*
4863 : * Since there is now no trace of the function in the plan tree, we must
4864 : * explicitly record the plan's dependency on the function.
4865 : */
4866 19494 : if (context->root)
4867 19352 : record_plan_function_dependency(context->root, funcid);
4868 :
4869 : /*
4870 : * Recursively try to simplify the modified expression. Here we must add
4871 : * the current function to the context list of active functions.
4872 : */
4873 19494 : context->active_fns = lappend_oid(context->active_fns, funcid);
4874 19494 : newexpr = eval_const_expressions_mutator(newexpr, context);
4875 19492 : context->active_fns = list_delete_last(context->active_fns);
4876 :
4877 19492 : error_context_stack = sqlerrcontext.previous;
4878 :
4879 19492 : return (Expr *) newexpr;
4880 :
4881 : /* Here if func is not inlinable: release temp memory and return NULL */
4882 2892 : fail:
4883 2892 : MemoryContextSwitchTo(oldcxt);
4884 2892 : MemoryContextDelete(mycxt);
4885 2892 : error_context_stack = sqlerrcontext.previous;
4886 :
4887 2892 : return NULL;
4888 : }
4889 :
4890 : /*
4891 : * Replace Param nodes by appropriate actual parameters
4892 : */
4893 : static Node *
4894 19494 : substitute_actual_parameters(Node *expr, int nargs, List *args,
4895 : int *usecounts)
4896 : {
4897 : substitute_actual_parameters_context context;
4898 :
4899 19494 : context.nargs = nargs;
4900 19494 : context.args = args;
4901 19494 : context.usecounts = usecounts;
4902 :
4903 19494 : return substitute_actual_parameters_mutator(expr, &context);
4904 : }
4905 :
4906 : static Node *
4907 165930 : substitute_actual_parameters_mutator(Node *node,
4908 : substitute_actual_parameters_context *context)
4909 : {
4910 165930 : if (node == NULL)
4911 17052 : return NULL;
4912 148878 : if (IsA(node, Param))
4913 : {
4914 38294 : Param *param = (Param *) node;
4915 :
4916 38294 : if (param->paramkind != PARAM_EXTERN)
4917 0 : elog(ERROR, "unexpected paramkind: %d", (int) param->paramkind);
4918 38294 : if (param->paramid <= 0 || param->paramid > context->nargs)
4919 0 : elog(ERROR, "invalid paramid: %d", param->paramid);
4920 :
4921 : /* Count usage of parameter */
4922 38294 : context->usecounts[param->paramid - 1]++;
4923 :
4924 : /* Select the appropriate actual arg and replace the Param with it */
4925 : /* We don't need to copy at this time (it'll get done later) */
4926 38294 : return list_nth(context->args, param->paramid - 1);
4927 : }
4928 110584 : return expression_tree_mutator(node, substitute_actual_parameters_mutator,
4929 : (void *) context);
4930 : }
4931 :
4932 : /*
4933 : * error context callback to let us supply a call-stack traceback
4934 : */
4935 : static void
4936 26 : sql_inline_error_callback(void *arg)
4937 : {
4938 26 : inline_error_callback_arg *callback_arg = (inline_error_callback_arg *) arg;
4939 : int syntaxerrposition;
4940 :
4941 : /* If it's a syntax error, convert to internal syntax error report */
4942 26 : syntaxerrposition = geterrposition();
4943 26 : if (syntaxerrposition > 0)
4944 : {
4945 6 : errposition(0);
4946 6 : internalerrposition(syntaxerrposition);
4947 6 : internalerrquery(callback_arg->prosrc);
4948 : }
4949 :
4950 26 : errcontext("SQL function \"%s\" during inlining", callback_arg->proname);
4951 26 : }
4952 :
4953 : /*
4954 : * evaluate_expr: pre-evaluate a constant expression
4955 : *
4956 : * We use the executor's routine ExecEvalExpr() to avoid duplication of
4957 : * code and ensure we get the same result as the executor would get.
4958 : */
4959 : Expr *
4960 202840 : evaluate_expr(Expr *expr, Oid result_type, int32 result_typmod,
4961 : Oid result_collation)
4962 : {
4963 : EState *estate;
4964 : ExprState *exprstate;
4965 : MemoryContext oldcontext;
4966 : Datum const_val;
4967 : bool const_is_null;
4968 : int16 resultTypLen;
4969 : bool resultTypByVal;
4970 :
4971 : /*
4972 : * To use the executor, we need an EState.
4973 : */
4974 202840 : estate = CreateExecutorState();
4975 :
4976 : /* We can use the estate's working context to avoid memory leaks. */
4977 202840 : oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
4978 :
4979 : /* Make sure any opfuncids are filled in. */
4980 202840 : fix_opfuncids((Node *) expr);
4981 :
4982 : /*
4983 : * Prepare expr for execution. (Note: we can't use ExecPrepareExpr
4984 : * because it'd result in recursively invoking eval_const_expressions.)
4985 : */
4986 202840 : exprstate = ExecInitExpr(expr, NULL);
4987 :
4988 : /*
4989 : * And evaluate it.
4990 : *
4991 : * It is OK to use a default econtext because none of the ExecEvalExpr()
4992 : * code used in this situation will use econtext. That might seem
4993 : * fortuitous, but it's not so unreasonable --- a constant expression does
4994 : * not depend on context, by definition, n'est ce pas?
4995 : */
4996 202822 : const_val = ExecEvalExprSwitchContext(exprstate,
4997 202822 : GetPerTupleExprContext(estate),
4998 : &const_is_null);
4999 :
5000 : /* Get info needed about result datatype */
5001 199298 : get_typlenbyval(result_type, &resultTypLen, &resultTypByVal);
5002 :
5003 : /* Get back to outer memory context */
5004 199298 : MemoryContextSwitchTo(oldcontext);
5005 :
5006 : /*
5007 : * Must copy result out of sub-context used by expression eval.
5008 : *
5009 : * Also, if it's varlena, forcibly detoast it. This protects us against
5010 : * storing TOAST pointers into plans that might outlive the referenced
5011 : * data. (makeConst would handle detoasting anyway, but it's worth a few
5012 : * extra lines here so that we can do the copy and detoast in one step.)
5013 : */
5014 199298 : if (!const_is_null)
5015 : {
5016 197904 : if (resultTypLen == -1)
5017 76106 : const_val = PointerGetDatum(PG_DETOAST_DATUM_COPY(const_val));
5018 : else
5019 121798 : const_val = datumCopy(const_val, resultTypByVal, resultTypLen);
5020 : }
5021 :
5022 : /* Release all the junk we just created */
5023 199298 : FreeExecutorState(estate);
5024 :
5025 : /*
5026 : * Make the constant result node.
5027 : */
5028 199298 : return (Expr *) makeConst(result_type, result_typmod, result_collation,
5029 : resultTypLen,
5030 : const_val, const_is_null,
5031 : resultTypByVal);
5032 : }
5033 :
5034 :
5035 : /*
5036 : * inline_set_returning_function
5037 : * Attempt to "inline" a set-returning function in the FROM clause.
5038 : *
5039 : * "rte" is an RTE_FUNCTION rangetable entry. If it represents a call of a
5040 : * set-returning SQL function that can safely be inlined, expand the function
5041 : * and return the substitute Query structure. Otherwise, return NULL.
5042 : *
5043 : * We assume that the RTE's expression has already been put through
5044 : * eval_const_expressions(), which among other things will take care of
5045 : * default arguments and named-argument notation.
5046 : *
5047 : * This has a good deal of similarity to inline_function(), but that's
5048 : * for the non-set-returning case, and there are enough differences to
5049 : * justify separate functions.
5050 : */
5051 : Query *
5052 40070 : inline_set_returning_function(PlannerInfo *root, RangeTblEntry *rte)
5053 : {
5054 : RangeTblFunction *rtfunc;
5055 : FuncExpr *fexpr;
5056 : Oid func_oid;
5057 : HeapTuple func_tuple;
5058 : Form_pg_proc funcform;
5059 : char *src;
5060 : Datum tmp;
5061 : bool isNull;
5062 : MemoryContext oldcxt;
5063 : MemoryContext mycxt;
5064 : inline_error_callback_arg callback_arg;
5065 : ErrorContextCallback sqlerrcontext;
5066 : SQLFunctionParseInfoPtr pinfo;
5067 : TypeFuncClass functypclass;
5068 : TupleDesc rettupdesc;
5069 : List *raw_parsetree_list;
5070 : List *querytree_list;
5071 : Query *querytree;
5072 :
5073 : Assert(rte->rtekind == RTE_FUNCTION);
5074 :
5075 : /*
5076 : * It doesn't make a lot of sense for a SQL SRF to refer to itself in its
5077 : * own FROM clause, since that must cause infinite recursion at runtime.
5078 : * It will cause this code to recurse too, so check for stack overflow.
5079 : * (There's no need to do more.)
5080 : */
5081 40070 : check_stack_depth();
5082 :
5083 : /* Fail if the RTE has ORDINALITY - we don't implement that here. */
5084 40070 : if (rte->funcordinality)
5085 686 : return NULL;
5086 :
5087 : /* Fail if RTE isn't a single, simple FuncExpr */
5088 39384 : if (list_length(rte->functions) != 1)
5089 72 : return NULL;
5090 39312 : rtfunc = (RangeTblFunction *) linitial(rte->functions);
5091 :
5092 39312 : if (!IsA(rtfunc->funcexpr, FuncExpr))
5093 414 : return NULL;
5094 38898 : fexpr = (FuncExpr *) rtfunc->funcexpr;
5095 :
5096 38898 : func_oid = fexpr->funcid;
5097 :
5098 : /*
5099 : * The function must be declared to return a set, else inlining would
5100 : * change the results if the contained SELECT didn't return exactly one
5101 : * row.
5102 : */
5103 38898 : if (!fexpr->funcretset)
5104 4140 : return NULL;
5105 :
5106 : /*
5107 : * Refuse to inline if the arguments contain any volatile functions or
5108 : * sub-selects. Volatile functions are rejected because inlining may
5109 : * result in the arguments being evaluated multiple times, risking a
5110 : * change in behavior. Sub-selects are rejected partly for implementation
5111 : * reasons (pushing them down another level might change their behavior)
5112 : * and partly because they're likely to be expensive and so multiple
5113 : * evaluation would be bad.
5114 : */
5115 69384 : if (contain_volatile_functions((Node *) fexpr->args) ||
5116 34626 : contain_subplans((Node *) fexpr->args))
5117 370 : return NULL;
5118 :
5119 : /* Check permission to call function (fail later, if not) */
5120 34388 : if (object_aclcheck(ProcedureRelationId, func_oid, GetUserId(), ACL_EXECUTE) != ACLCHECK_OK)
5121 8 : return NULL;
5122 :
5123 : /* Check whether a plugin wants to hook function entry/exit */
5124 34380 : if (FmgrHookIsNeeded(func_oid))
5125 0 : return NULL;
5126 :
5127 : /*
5128 : * OK, let's take a look at the function's pg_proc entry.
5129 : */
5130 34380 : func_tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(func_oid));
5131 34380 : if (!HeapTupleIsValid(func_tuple))
5132 0 : elog(ERROR, "cache lookup failed for function %u", func_oid);
5133 34380 : funcform = (Form_pg_proc) GETSTRUCT(func_tuple);
5134 :
5135 : /*
5136 : * Forget it if the function is not SQL-language or has other showstopper
5137 : * properties. In particular it mustn't be declared STRICT, since we
5138 : * couldn't enforce that. It also mustn't be VOLATILE, because that is
5139 : * supposed to cause it to be executed with its own snapshot, rather than
5140 : * sharing the snapshot of the calling query. We also disallow returning
5141 : * SETOF VOID, because inlining would result in exposing the actual result
5142 : * of the function's last SELECT, which should not happen in that case.
5143 : * (Rechecking prokind, proretset, and pronargs is just paranoia.)
5144 : */
5145 34380 : if (funcform->prolang != SQLlanguageId ||
5146 576 : funcform->prokind != PROKIND_FUNCTION ||
5147 576 : funcform->proisstrict ||
5148 516 : funcform->provolatile == PROVOLATILE_VOLATILE ||
5149 162 : funcform->prorettype == VOIDOID ||
5150 156 : funcform->prosecdef ||
5151 156 : !funcform->proretset ||
5152 156 : list_length(fexpr->args) != funcform->pronargs ||
5153 156 : !heap_attisnull(func_tuple, Anum_pg_proc_proconfig, NULL))
5154 : {
5155 34224 : ReleaseSysCache(func_tuple);
5156 34224 : return NULL;
5157 : }
5158 :
5159 : /*
5160 : * Make a temporary memory context, so that we don't leak all the stuff
5161 : * that parsing might create.
5162 : */
5163 156 : mycxt = AllocSetContextCreate(CurrentMemoryContext,
5164 : "inline_set_returning_function",
5165 : ALLOCSET_DEFAULT_SIZES);
5166 156 : oldcxt = MemoryContextSwitchTo(mycxt);
5167 :
5168 : /* Fetch the function body */
5169 156 : tmp = SysCacheGetAttrNotNull(PROCOID, func_tuple, Anum_pg_proc_prosrc);
5170 156 : src = TextDatumGetCString(tmp);
5171 :
5172 : /*
5173 : * Setup error traceback support for ereport(). This is so that we can
5174 : * finger the function that bad information came from.
5175 : */
5176 156 : callback_arg.proname = NameStr(funcform->proname);
5177 156 : callback_arg.prosrc = src;
5178 :
5179 156 : sqlerrcontext.callback = sql_inline_error_callback;
5180 156 : sqlerrcontext.arg = (void *) &callback_arg;
5181 156 : sqlerrcontext.previous = error_context_stack;
5182 156 : error_context_stack = &sqlerrcontext;
5183 :
5184 : /* If we have prosqlbody, pay attention to that not prosrc */
5185 156 : tmp = SysCacheGetAttr(PROCOID,
5186 : func_tuple,
5187 : Anum_pg_proc_prosqlbody,
5188 : &isNull);
5189 156 : if (!isNull)
5190 : {
5191 : Node *n;
5192 :
5193 12 : n = stringToNode(TextDatumGetCString(tmp));
5194 12 : if (IsA(n, List))
5195 12 : querytree_list = linitial_node(List, castNode(List, n));
5196 : else
5197 0 : querytree_list = list_make1(n);
5198 12 : if (list_length(querytree_list) != 1)
5199 0 : goto fail;
5200 12 : querytree = linitial(querytree_list);
5201 :
5202 : /* Acquire necessary locks, then apply rewriter. */
5203 12 : AcquireRewriteLocks(querytree, true, false);
5204 12 : querytree_list = pg_rewrite_query(querytree);
5205 12 : if (list_length(querytree_list) != 1)
5206 0 : goto fail;
5207 12 : querytree = linitial(querytree_list);
5208 : }
5209 : else
5210 : {
5211 : /*
5212 : * Set up to handle parameters while parsing the function body. We
5213 : * can use the FuncExpr just created as the input for
5214 : * prepare_sql_fn_parse_info.
5215 : */
5216 144 : pinfo = prepare_sql_fn_parse_info(func_tuple,
5217 : (Node *) fexpr,
5218 : fexpr->inputcollid);
5219 :
5220 : /*
5221 : * Parse, analyze, and rewrite (unlike inline_function(), we can't
5222 : * skip rewriting here). We can fail as soon as we find more than one
5223 : * query, though.
5224 : */
5225 144 : raw_parsetree_list = pg_parse_query(src);
5226 144 : if (list_length(raw_parsetree_list) != 1)
5227 0 : goto fail;
5228 :
5229 144 : querytree_list = pg_analyze_and_rewrite_withcb(linitial(raw_parsetree_list),
5230 : src,
5231 : (ParserSetupHook) sql_fn_parser_setup,
5232 : pinfo, NULL);
5233 144 : if (list_length(querytree_list) != 1)
5234 0 : goto fail;
5235 144 : querytree = linitial(querytree_list);
5236 : }
5237 :
5238 : /*
5239 : * Also resolve the actual function result tupdesc, if composite. If we
5240 : * have a coldeflist, believe that; otherwise use get_expr_result_type.
5241 : * (This logic should match ExecInitFunctionScan.)
5242 : */
5243 156 : if (rtfunc->funccolnames != NIL)
5244 : {
5245 24 : functypclass = TYPEFUNC_RECORD;
5246 24 : rettupdesc = BuildDescFromLists(rtfunc->funccolnames,
5247 24 : rtfunc->funccoltypes,
5248 24 : rtfunc->funccoltypmods,
5249 24 : rtfunc->funccolcollations);
5250 : }
5251 : else
5252 132 : functypclass = get_expr_result_type((Node *) fexpr, NULL, &rettupdesc);
5253 :
5254 : /*
5255 : * The single command must be a plain SELECT.
5256 : */
5257 156 : if (!IsA(querytree, Query) ||
5258 156 : querytree->commandType != CMD_SELECT)
5259 0 : goto fail;
5260 :
5261 : /*
5262 : * Make sure the function (still) returns what it's declared to. This
5263 : * will raise an error if wrong, but that's okay since the function would
5264 : * fail at runtime anyway. Note that check_sql_fn_retval will also insert
5265 : * coercions if needed to make the tlist expression(s) match the declared
5266 : * type of the function. We also ask it to insert dummy NULL columns for
5267 : * any dropped columns in rettupdesc, so that the elements of the modified
5268 : * tlist match up to the attribute numbers.
5269 : *
5270 : * If the function returns a composite type, don't inline unless the check
5271 : * shows it's returning a whole tuple result; otherwise what it's
5272 : * returning is a single composite column which is not what we need.
5273 : */
5274 156 : if (!check_sql_fn_retval(list_make1(querytree_list),
5275 : fexpr->funcresulttype, rettupdesc,
5276 156 : funcform->prokind,
5277 90 : true, NULL) &&
5278 90 : (functypclass == TYPEFUNC_COMPOSITE ||
5279 90 : functypclass == TYPEFUNC_COMPOSITE_DOMAIN ||
5280 : functypclass == TYPEFUNC_RECORD))
5281 0 : goto fail; /* reject not-whole-tuple-result cases */
5282 :
5283 : /*
5284 : * check_sql_fn_retval might've inserted a projection step, but that's
5285 : * fine; just make sure we use the upper Query.
5286 : */
5287 150 : querytree = linitial_node(Query, querytree_list);
5288 :
5289 : /*
5290 : * Looks good --- substitute parameters into the query.
5291 : */
5292 150 : querytree = substitute_actual_srf_parameters(querytree,
5293 150 : funcform->pronargs,
5294 : fexpr->args);
5295 :
5296 : /*
5297 : * Copy the modified query out of the temporary memory context, and clean
5298 : * up.
5299 : */
5300 150 : MemoryContextSwitchTo(oldcxt);
5301 :
5302 150 : querytree = copyObject(querytree);
5303 :
5304 150 : MemoryContextDelete(mycxt);
5305 150 : error_context_stack = sqlerrcontext.previous;
5306 150 : ReleaseSysCache(func_tuple);
5307 :
5308 : /*
5309 : * We don't have to fix collations here because the upper query is already
5310 : * parsed, ie, the collations in the RTE are what count.
5311 : */
5312 :
5313 : /*
5314 : * Since there is now no trace of the function in the plan tree, we must
5315 : * explicitly record the plan's dependency on the function.
5316 : */
5317 150 : record_plan_function_dependency(root, func_oid);
5318 :
5319 : /*
5320 : * We must also notice if the inserted query adds a dependency on the
5321 : * calling role due to RLS quals.
5322 : */
5323 150 : if (querytree->hasRowSecurity)
5324 12 : root->glob->dependsOnRole = true;
5325 :
5326 150 : return querytree;
5327 :
5328 : /* Here if func is not inlinable: release temp memory and return NULL */
5329 0 : fail:
5330 0 : MemoryContextSwitchTo(oldcxt);
5331 0 : MemoryContextDelete(mycxt);
5332 0 : error_context_stack = sqlerrcontext.previous;
5333 0 : ReleaseSysCache(func_tuple);
5334 :
5335 0 : return NULL;
5336 : }
5337 :
5338 : /*
5339 : * Replace Param nodes by appropriate actual parameters
5340 : *
5341 : * This is just enough different from substitute_actual_parameters()
5342 : * that it needs its own code.
5343 : */
5344 : static Query *
5345 150 : substitute_actual_srf_parameters(Query *expr, int nargs, List *args)
5346 : {
5347 : substitute_actual_srf_parameters_context context;
5348 :
5349 150 : context.nargs = nargs;
5350 150 : context.args = args;
5351 150 : context.sublevels_up = 1;
5352 :
5353 150 : return query_tree_mutator(expr,
5354 : substitute_actual_srf_parameters_mutator,
5355 : &context,
5356 : 0);
5357 : }
5358 :
5359 : static Node *
5360 5286 : substitute_actual_srf_parameters_mutator(Node *node,
5361 : substitute_actual_srf_parameters_context *context)
5362 : {
5363 : Node *result;
5364 :
5365 5286 : if (node == NULL)
5366 2880 : return NULL;
5367 2406 : if (IsA(node, Query))
5368 : {
5369 78 : context->sublevels_up++;
5370 78 : result = (Node *) query_tree_mutator((Query *) node,
5371 : substitute_actual_srf_parameters_mutator,
5372 : (void *) context,
5373 : 0);
5374 78 : context->sublevels_up--;
5375 78 : return result;
5376 : }
5377 2328 : if (IsA(node, Param))
5378 : {
5379 102 : Param *param = (Param *) node;
5380 :
5381 102 : if (param->paramkind == PARAM_EXTERN)
5382 : {
5383 102 : if (param->paramid <= 0 || param->paramid > context->nargs)
5384 0 : elog(ERROR, "invalid paramid: %d", param->paramid);
5385 :
5386 : /*
5387 : * Since the parameter is being inserted into a subquery, we must
5388 : * adjust levels.
5389 : */
5390 102 : result = copyObject(list_nth(context->args, param->paramid - 1));
5391 102 : IncrementVarSublevelsUp(result, context->sublevels_up, 0);
5392 102 : return result;
5393 : }
5394 : }
5395 2226 : return expression_tree_mutator(node,
5396 : substitute_actual_srf_parameters_mutator,
5397 : (void *) context);
5398 : }
5399 :
5400 : /*
5401 : * pull_paramids
5402 : * Returns a Bitmapset containing the paramids of all Params in 'expr'.
5403 : */
5404 : Bitmapset *
5405 1336 : pull_paramids(Expr *expr)
5406 : {
5407 1336 : Bitmapset *result = NULL;
5408 :
5409 1336 : (void) pull_paramids_walker((Node *) expr, &result);
5410 :
5411 1336 : return result;
5412 : }
5413 :
5414 : static bool
5415 2948 : pull_paramids_walker(Node *node, Bitmapset **context)
5416 : {
5417 2948 : if (node == NULL)
5418 30 : return false;
5419 2918 : if (IsA(node, Param))
5420 : {
5421 1366 : Param *param = (Param *) node;
5422 :
5423 1366 : *context = bms_add_member(*context, param->paramid);
5424 1366 : return false;
5425 : }
5426 1552 : return expression_tree_walker(node, pull_paramids_walker,
5427 : (void *) context);
5428 : }
|
