Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * deparse.c
4 : * Query deparser for postgres_fdw
5 : *
6 : * This file includes functions that examine query WHERE clauses to see
7 : * whether they're safe to send to the remote server for execution, as
8 : * well as functions to construct the query text to be sent. The latter
9 : * functionality is annoyingly duplicative of ruleutils.c, but there are
10 : * enough special considerations that it seems best to keep this separate.
11 : * One saving grace is that we only need deparse logic for node types that
12 : * we consider safe to send.
13 : *
14 : * We assume that the remote session's search_path is exactly "pg_catalog",
15 : * and thus we need schema-qualify all and only names outside pg_catalog.
16 : *
17 : * We do not consider that it is ever safe to send COLLATE expressions to
18 : * the remote server: it might not have the same collation names we do.
19 : * (Later we might consider it safe to send COLLATE "C", but even that would
20 : * fail on old remote servers.) An expression is considered safe to send
21 : * only if all operator/function input collations used in it are traceable to
22 : * Var(s) of the foreign table. That implies that if the remote server gets
23 : * a different answer than we do, the foreign table's columns are not marked
24 : * with collations that match the remote table's columns, which we can
25 : * consider to be user error.
26 : *
27 : * Portions Copyright (c) 2012-2020, PostgreSQL Global Development Group
28 : *
29 : * IDENTIFICATION
30 : * contrib/postgres_fdw/deparse.c
31 : *
32 : *-------------------------------------------------------------------------
33 : */
34 : #include "postgres.h"
35 :
36 : #include "access/htup_details.h"
37 : #include "access/sysattr.h"
38 : #include "access/table.h"
39 : #include "catalog/pg_aggregate.h"
40 : #include "catalog/pg_collation.h"
41 : #include "catalog/pg_namespace.h"
42 : #include "catalog/pg_operator.h"
43 : #include "catalog/pg_proc.h"
44 : #include "catalog/pg_type.h"
45 : #include "commands/defrem.h"
46 : #include "nodes/makefuncs.h"
47 : #include "nodes/nodeFuncs.h"
48 : #include "nodes/plannodes.h"
49 : #include "optimizer/optimizer.h"
50 : #include "optimizer/prep.h"
51 : #include "optimizer/tlist.h"
52 : #include "parser/parsetree.h"
53 : #include "postgres_fdw.h"
54 : #include "utils/builtins.h"
55 : #include "utils/lsyscache.h"
56 : #include "utils/rel.h"
57 : #include "utils/syscache.h"
58 : #include "utils/typcache.h"
59 :
60 : /*
61 : * Global context for foreign_expr_walker's search of an expression tree.
62 : */
63 : typedef struct foreign_glob_cxt
64 : {
65 : PlannerInfo *root; /* global planner state */
66 : RelOptInfo *foreignrel; /* the foreign relation we are planning for */
67 : Relids relids; /* relids of base relations in the underlying
68 : * scan */
69 : } foreign_glob_cxt;
70 :
71 : /*
72 : * Local (per-tree-level) context for foreign_expr_walker's search.
73 : * This is concerned with identifying collations used in the expression.
74 : */
75 : typedef enum
76 : {
77 : FDW_COLLATE_NONE, /* expression is of a noncollatable type, or
78 : * it has default collation that is not
79 : * traceable to a foreign Var */
80 : FDW_COLLATE_SAFE, /* collation derives from a foreign Var */
81 : FDW_COLLATE_UNSAFE /* collation is non-default and derives from
82 : * something other than a foreign Var */
83 : } FDWCollateState;
84 :
85 : typedef struct foreign_loc_cxt
86 : {
87 : Oid collation; /* OID of current collation, if any */
88 : FDWCollateState state; /* state of current collation choice */
89 : } foreign_loc_cxt;
90 :
91 : /*
92 : * Context for deparseExpr
93 : */
94 : typedef struct deparse_expr_cxt
95 : {
96 : PlannerInfo *root; /* global planner state */
97 : RelOptInfo *foreignrel; /* the foreign relation we are planning for */
98 : RelOptInfo *scanrel; /* the underlying scan relation. Same as
99 : * foreignrel, when that represents a join or
100 : * a base relation. */
101 : StringInfo buf; /* output buffer to append to */
102 : List **params_list; /* exprs that will become remote Params */
103 : } deparse_expr_cxt;
104 :
105 : #define REL_ALIAS_PREFIX "r"
106 : /* Handy macro to add relation name qualification */
107 : #define ADD_REL_QUALIFIER(buf, varno) \
108 : appendStringInfo((buf), "%s%d.", REL_ALIAS_PREFIX, (varno))
109 : #define SUBQUERY_REL_ALIAS_PREFIX "s"
110 : #define SUBQUERY_COL_ALIAS_PREFIX "c"
111 :
112 : /*
113 : * Functions to determine whether an expression can be evaluated safely on
114 : * remote server.
115 : */
116 : static bool foreign_expr_walker(Node *node,
117 : foreign_glob_cxt *glob_cxt,
118 : foreign_loc_cxt *outer_cxt);
119 : static char *deparse_type_name(Oid type_oid, int32 typemod);
120 :
121 : /*
122 : * Functions to construct string representation of a node tree.
123 : */
124 : static void deparseTargetList(StringInfo buf,
125 : RangeTblEntry *rte,
126 : Index rtindex,
127 : Relation rel,
128 : bool is_returning,
129 : Bitmapset *attrs_used,
130 : bool qualify_col,
131 : List **retrieved_attrs);
132 : static void deparseExplicitTargetList(List *tlist,
133 : bool is_returning,
134 : List **retrieved_attrs,
135 : deparse_expr_cxt *context);
136 : static void deparseSubqueryTargetList(deparse_expr_cxt *context);
137 : static void deparseReturningList(StringInfo buf, RangeTblEntry *rte,
138 : Index rtindex, Relation rel,
139 : bool trig_after_row,
140 : List *withCheckOptionList,
141 : List *returningList,
142 : List **retrieved_attrs);
143 : static void deparseColumnRef(StringInfo buf, int varno, int varattno,
144 : RangeTblEntry *rte, bool qualify_col);
145 : static void deparseRelation(StringInfo buf, Relation rel);
146 : static void deparseExpr(Expr *expr, deparse_expr_cxt *context);
147 : static void deparseVar(Var *node, deparse_expr_cxt *context);
148 : static void deparseConst(Const *node, deparse_expr_cxt *context, int showtype);
149 : static void deparseParam(Param *node, deparse_expr_cxt *context);
150 : static void deparseSubscriptingRef(SubscriptingRef *node, deparse_expr_cxt *context);
151 : static void deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context);
152 : static void deparseOpExpr(OpExpr *node, deparse_expr_cxt *context);
153 : static void deparseOperatorName(StringInfo buf, Form_pg_operator opform);
154 : static void deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context);
155 : static void deparseScalarArrayOpExpr(ScalarArrayOpExpr *node,
156 : deparse_expr_cxt *context);
157 : static void deparseRelabelType(RelabelType *node, deparse_expr_cxt *context);
158 : static void deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context);
159 : static void deparseNullTest(NullTest *node, deparse_expr_cxt *context);
160 : static void deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context);
161 : static void printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod,
162 : deparse_expr_cxt *context);
163 : static void printRemotePlaceholder(Oid paramtype, int32 paramtypmod,
164 : deparse_expr_cxt *context);
165 : static void deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs,
166 : deparse_expr_cxt *context);
167 : static void deparseLockingClause(deparse_expr_cxt *context);
168 : static void appendOrderByClause(List *pathkeys, bool has_final_sort,
169 : deparse_expr_cxt *context);
170 : static void appendLimitClause(deparse_expr_cxt *context);
171 : static void appendConditions(List *exprs, deparse_expr_cxt *context);
172 : static void deparseFromExprForRel(StringInfo buf, PlannerInfo *root,
173 : RelOptInfo *foreignrel, bool use_alias,
174 : Index ignore_rel, List **ignore_conds,
175 : List **params_list);
176 : static void deparseFromExpr(List *quals, deparse_expr_cxt *context);
177 : static void deparseRangeTblRef(StringInfo buf, PlannerInfo *root,
178 : RelOptInfo *foreignrel, bool make_subquery,
179 : Index ignore_rel, List **ignore_conds, List **params_list);
180 : static void deparseAggref(Aggref *node, deparse_expr_cxt *context);
181 : static void appendGroupByClause(List *tlist, deparse_expr_cxt *context);
182 : static void appendAggOrderBy(List *orderList, List *targetList,
183 : deparse_expr_cxt *context);
184 : static void appendFunctionName(Oid funcid, deparse_expr_cxt *context);
185 : static Node *deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
186 : deparse_expr_cxt *context);
187 :
188 : /*
189 : * Helper functions
190 : */
191 : static bool is_subquery_var(Var *node, RelOptInfo *foreignrel,
192 : int *relno, int *colno);
193 : static void get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel,
194 : int *relno, int *colno);
195 :
196 :
197 : /*
198 : * Examine each qual clause in input_conds, and classify them into two groups,
199 : * which are returned as two lists:
200 : * - remote_conds contains expressions that can be evaluated remotely
201 : * - local_conds contains expressions that can't be evaluated remotely
202 : */
203 : void
204 3492 : classifyConditions(PlannerInfo *root,
205 : RelOptInfo *baserel,
206 : List *input_conds,
207 : List **remote_conds,
208 : List **local_conds)
209 : {
210 : ListCell *lc;
211 :
212 3492 : *remote_conds = NIL;
213 3492 : *local_conds = NIL;
214 :
215 4582 : foreach(lc, input_conds)
216 : {
217 1090 : RestrictInfo *ri = lfirst_node(RestrictInfo, lc);
218 :
219 1090 : if (is_foreign_expr(root, baserel, ri->clause))
220 1014 : *remote_conds = lappend(*remote_conds, ri);
221 : else
222 76 : *local_conds = lappend(*local_conds, ri);
223 : }
224 3492 : }
225 :
226 : /*
227 : * Returns true if given expr is safe to evaluate on the foreign server.
228 : */
229 : bool
230 4406 : is_foreign_expr(PlannerInfo *root,
231 : RelOptInfo *baserel,
232 : Expr *expr)
233 : {
234 : foreign_glob_cxt glob_cxt;
235 : foreign_loc_cxt loc_cxt;
236 4406 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) (baserel->fdw_private);
237 :
238 : /*
239 : * Check that the expression consists of nodes that are safe to execute
240 : * remotely.
241 : */
242 4406 : glob_cxt.root = root;
243 4406 : glob_cxt.foreignrel = baserel;
244 :
245 : /*
246 : * For an upper relation, use relids from its underneath scan relation,
247 : * because the upperrel's own relids currently aren't set to anything
248 : * meaningful by the core code. For other relation, use their own relids.
249 : */
250 4406 : if (IS_UPPER_REL(baserel))
251 744 : glob_cxt.relids = fpinfo->outerrel->relids;
252 : else
253 3662 : glob_cxt.relids = baserel->relids;
254 4406 : loc_cxt.collation = InvalidOid;
255 4406 : loc_cxt.state = FDW_COLLATE_NONE;
256 4406 : if (!foreign_expr_walker((Node *) expr, &glob_cxt, &loc_cxt))
257 210 : return false;
258 :
259 : /*
260 : * If the expression has a valid collation that does not arise from a
261 : * foreign var, the expression can not be sent over.
262 : */
263 4196 : if (loc_cxt.state == FDW_COLLATE_UNSAFE)
264 4 : return false;
265 :
266 : /*
267 : * An expression which includes any mutable functions can't be sent over
268 : * because its result is not stable. For example, sending now() remote
269 : * side could cause confusion from clock offsets. Future versions might
270 : * be able to make this choice with more granularity. (We check this last
271 : * because it requires a lot of expensive catalog lookups.)
272 : */
273 4192 : if (contain_mutable_functions((Node *) expr))
274 42 : return false;
275 :
276 : /* OK to evaluate on the remote server */
277 4150 : return true;
278 : }
279 :
280 : /*
281 : * Check if expression is safe to execute remotely, and return true if so.
282 : *
283 : * In addition, *outer_cxt is updated with collation information.
284 : *
285 : * We must check that the expression contains only node types we can deparse,
286 : * that all types/functions/operators are safe to send (they are "shippable"),
287 : * and that all collations used in the expression derive from Vars of the
288 : * foreign table. Because of the latter, the logic is pretty close to
289 : * assign_collations_walker() in parse_collate.c, though we can assume here
290 : * that the given expression is valid. Note function mutability is not
291 : * currently considered here.
292 : */
293 : static bool
294 12766 : foreign_expr_walker(Node *node,
295 : foreign_glob_cxt *glob_cxt,
296 : foreign_loc_cxt *outer_cxt)
297 : {
298 12766 : bool check_type = true;
299 : PgFdwRelationInfo *fpinfo;
300 : foreign_loc_cxt inner_cxt;
301 : Oid collation;
302 : FDWCollateState state;
303 :
304 : /* Need do nothing for empty subexpressions */
305 12766 : if (node == NULL)
306 488 : return true;
307 :
308 : /* May need server info from baserel's fdw_private struct */
309 12278 : fpinfo = (PgFdwRelationInfo *) (glob_cxt->foreignrel->fdw_private);
310 :
311 : /* Set up inner_cxt for possible recursion to child nodes */
312 12278 : inner_cxt.collation = InvalidOid;
313 12278 : inner_cxt.state = FDW_COLLATE_NONE;
314 :
315 12278 : switch (nodeTag(node))
316 : {
317 4988 : case T_Var:
318 : {
319 4988 : Var *var = (Var *) node;
320 :
321 : /*
322 : * If the Var is from the foreign table, we consider its
323 : * collation (if any) safe to use. If it is from another
324 : * table, we treat its collation the same way as we would a
325 : * Param's collation, ie it's not safe for it to have a
326 : * non-default collation.
327 : */
328 4988 : if (bms_is_member(var->varno, glob_cxt->relids) &&
329 4396 : var->varlevelsup == 0)
330 : {
331 : /* Var belongs to foreign table */
332 :
333 : /*
334 : * System columns other than ctid should not be sent to
335 : * the remote, since we don't make any effort to ensure
336 : * that local and remote values match (tableoid, in
337 : * particular, almost certainly doesn't match).
338 : */
339 4396 : if (var->varattno < 0 &&
340 16 : var->varattno != SelfItemPointerAttributeNumber)
341 12 : return false;
342 :
343 : /* Else check the collation */
344 4384 : collation = var->varcollid;
345 4384 : state = OidIsValid(collation) ? FDW_COLLATE_SAFE : FDW_COLLATE_NONE;
346 : }
347 : else
348 : {
349 : /* Var belongs to some other table */
350 592 : collation = var->varcollid;
351 592 : if (collation == InvalidOid ||
352 : collation == DEFAULT_COLLATION_OID)
353 : {
354 : /*
355 : * It's noncollatable, or it's safe to combine with a
356 : * collatable foreign Var, so set state to NONE.
357 : */
358 592 : state = FDW_COLLATE_NONE;
359 : }
360 : else
361 : {
362 : /*
363 : * Do not fail right away, since the Var might appear
364 : * in a collation-insensitive context.
365 : */
366 0 : state = FDW_COLLATE_UNSAFE;
367 : }
368 : }
369 : }
370 4976 : break;
371 1436 : case T_Const:
372 : {
373 1436 : Const *c = (Const *) node;
374 :
375 : /*
376 : * If the constant has nondefault collation, either it's of a
377 : * non-builtin type, or it reflects folding of a CollateExpr.
378 : * It's unsafe to send to the remote unless it's used in a
379 : * non-collation-sensitive context.
380 : */
381 1436 : collation = c->constcollid;
382 1436 : if (collation == InvalidOid ||
383 : collation == DEFAULT_COLLATION_OID)
384 1432 : state = FDW_COLLATE_NONE;
385 : else
386 4 : state = FDW_COLLATE_UNSAFE;
387 : }
388 1436 : break;
389 46 : case T_Param:
390 : {
391 46 : Param *p = (Param *) node;
392 :
393 : /*
394 : * If it's a MULTIEXPR Param, punt. We can't tell from here
395 : * whether the referenced sublink/subplan contains any remote
396 : * Vars; if it does, handling that is too complicated to
397 : * consider supporting at present. Fortunately, MULTIEXPR
398 : * Params are not reduced to plain PARAM_EXEC until the end of
399 : * planning, so we can easily detect this case. (Normal
400 : * PARAM_EXEC Params are safe to ship because their values
401 : * come from somewhere else in the plan tree; but a MULTIEXPR
402 : * references a sub-select elsewhere in the same targetlist,
403 : * so we'd be on the hook to evaluate it somehow if we wanted
404 : * to handle such cases as direct foreign updates.)
405 : */
406 46 : if (p->paramkind == PARAM_MULTIEXPR)
407 6 : return false;
408 :
409 : /*
410 : * Collation rule is same as for Consts and non-foreign Vars.
411 : */
412 40 : collation = p->paramcollid;
413 40 : if (collation == InvalidOid ||
414 : collation == DEFAULT_COLLATION_OID)
415 40 : state = FDW_COLLATE_NONE;
416 : else
417 0 : state = FDW_COLLATE_UNSAFE;
418 : }
419 40 : break;
420 2 : case T_SubscriptingRef:
421 : {
422 2 : SubscriptingRef *sr = (SubscriptingRef *) node;
423 :
424 : /* Assignment should not be in restrictions. */
425 2 : if (sr->refassgnexpr != NULL)
426 0 : return false;
427 :
428 : /*
429 : * Recurse to remaining subexpressions. Since the container
430 : * subscripts must yield (noncollatable) integers, they won't
431 : * affect the inner_cxt state.
432 : */
433 2 : if (!foreign_expr_walker((Node *) sr->refupperindexpr,
434 : glob_cxt, &inner_cxt))
435 0 : return false;
436 2 : if (!foreign_expr_walker((Node *) sr->reflowerindexpr,
437 : glob_cxt, &inner_cxt))
438 0 : return false;
439 2 : if (!foreign_expr_walker((Node *) sr->refexpr,
440 : glob_cxt, &inner_cxt))
441 0 : return false;
442 :
443 : /*
444 : * Container subscripting should yield same collation as
445 : * input, but for safety use same logic as for function nodes.
446 : */
447 2 : collation = sr->refcollid;
448 2 : if (collation == InvalidOid)
449 2 : state = FDW_COLLATE_NONE;
450 0 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
451 0 : collation == inner_cxt.collation)
452 0 : state = FDW_COLLATE_SAFE;
453 0 : else if (collation == DEFAULT_COLLATION_OID)
454 0 : state = FDW_COLLATE_NONE;
455 : else
456 0 : state = FDW_COLLATE_UNSAFE;
457 : }
458 2 : break;
459 212 : case T_FuncExpr:
460 : {
461 212 : FuncExpr *fe = (FuncExpr *) node;
462 :
463 : /*
464 : * If function used by the expression is not shippable, it
465 : * can't be sent to remote because it might have incompatible
466 : * semantics on remote side.
467 : */
468 212 : if (!is_shippable(fe->funcid, ProcedureRelationId, fpinfo))
469 10 : return false;
470 :
471 : /*
472 : * Recurse to input subexpressions.
473 : */
474 202 : if (!foreign_expr_walker((Node *) fe->args,
475 : glob_cxt, &inner_cxt))
476 12 : return false;
477 :
478 : /*
479 : * If function's input collation is not derived from a foreign
480 : * Var, it can't be sent to remote.
481 : */
482 190 : if (fe->inputcollid == InvalidOid)
483 : /* OK, inputs are all noncollatable */ ;
484 44 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
485 24 : fe->inputcollid != inner_cxt.collation)
486 20 : return false;
487 :
488 : /*
489 : * Detect whether node is introducing a collation not derived
490 : * from a foreign Var. (If so, we just mark it unsafe for now
491 : * rather than immediately returning false, since the parent
492 : * node might not care.)
493 : */
494 170 : collation = fe->funccollid;
495 170 : if (collation == InvalidOid)
496 146 : state = FDW_COLLATE_NONE;
497 24 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
498 24 : collation == inner_cxt.collation)
499 24 : state = FDW_COLLATE_SAFE;
500 0 : else if (collation == DEFAULT_COLLATION_OID)
501 0 : state = FDW_COLLATE_NONE;
502 : else
503 0 : state = FDW_COLLATE_UNSAFE;
504 : }
505 170 : break;
506 2292 : case T_OpExpr:
507 : case T_DistinctExpr: /* struct-equivalent to OpExpr */
508 : {
509 2292 : OpExpr *oe = (OpExpr *) node;
510 :
511 : /*
512 : * Similarly, only shippable operators can be sent to remote.
513 : * (If the operator is shippable, we assume its underlying
514 : * function is too.)
515 : */
516 2292 : if (!is_shippable(oe->opno, OperatorRelationId, fpinfo))
517 26 : return false;
518 :
519 : /*
520 : * Recurse to input subexpressions.
521 : */
522 2266 : if (!foreign_expr_walker((Node *) oe->args,
523 : glob_cxt, &inner_cxt))
524 76 : return false;
525 :
526 : /*
527 : * If operator's input collation is not derived from a foreign
528 : * Var, it can't be sent to remote.
529 : */
530 2190 : if (oe->inputcollid == InvalidOid)
531 : /* OK, inputs are all noncollatable */ ;
532 104 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
533 94 : oe->inputcollid != inner_cxt.collation)
534 10 : return false;
535 :
536 : /* Result-collation handling is same as for functions */
537 2180 : collation = oe->opcollid;
538 2180 : if (collation == InvalidOid)
539 2164 : state = FDW_COLLATE_NONE;
540 16 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
541 16 : collation == inner_cxt.collation)
542 16 : state = FDW_COLLATE_SAFE;
543 0 : else if (collation == DEFAULT_COLLATION_OID)
544 0 : state = FDW_COLLATE_NONE;
545 : else
546 0 : state = FDW_COLLATE_UNSAFE;
547 : }
548 2180 : break;
549 6 : case T_ScalarArrayOpExpr:
550 : {
551 6 : ScalarArrayOpExpr *oe = (ScalarArrayOpExpr *) node;
552 :
553 : /*
554 : * Again, only shippable operators can be sent to remote.
555 : */
556 6 : if (!is_shippable(oe->opno, OperatorRelationId, fpinfo))
557 0 : return false;
558 :
559 : /*
560 : * Recurse to input subexpressions.
561 : */
562 6 : if (!foreign_expr_walker((Node *) oe->args,
563 : glob_cxt, &inner_cxt))
564 0 : return false;
565 :
566 : /*
567 : * If operator's input collation is not derived from a foreign
568 : * Var, it can't be sent to remote.
569 : */
570 6 : if (oe->inputcollid == InvalidOid)
571 : /* OK, inputs are all noncollatable */ ;
572 0 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
573 0 : oe->inputcollid != inner_cxt.collation)
574 0 : return false;
575 :
576 : /* Output is always boolean and so noncollatable. */
577 6 : collation = InvalidOid;
578 6 : state = FDW_COLLATE_NONE;
579 : }
580 6 : break;
581 82 : case T_RelabelType:
582 : {
583 82 : RelabelType *r = (RelabelType *) node;
584 :
585 : /*
586 : * Recurse to input subexpression.
587 : */
588 82 : if (!foreign_expr_walker((Node *) r->arg,
589 : glob_cxt, &inner_cxt))
590 0 : return false;
591 :
592 : /*
593 : * RelabelType must not introduce a collation not derived from
594 : * an input foreign Var (same logic as for a real function).
595 : */
596 82 : collation = r->resultcollid;
597 82 : if (collation == InvalidOid)
598 0 : state = FDW_COLLATE_NONE;
599 82 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
600 74 : collation == inner_cxt.collation)
601 64 : state = FDW_COLLATE_SAFE;
602 18 : else if (collation == DEFAULT_COLLATION_OID)
603 6 : state = FDW_COLLATE_NONE;
604 : else
605 12 : state = FDW_COLLATE_UNSAFE;
606 : }
607 82 : break;
608 72 : case T_BoolExpr:
609 : {
610 72 : BoolExpr *b = (BoolExpr *) node;
611 :
612 : /*
613 : * Recurse to input subexpressions.
614 : */
615 72 : if (!foreign_expr_walker((Node *) b->args,
616 : glob_cxt, &inner_cxt))
617 0 : return false;
618 :
619 : /* Output is always boolean and so noncollatable. */
620 72 : collation = InvalidOid;
621 72 : state = FDW_COLLATE_NONE;
622 : }
623 72 : break;
624 54 : case T_NullTest:
625 : {
626 54 : NullTest *nt = (NullTest *) node;
627 :
628 : /*
629 : * Recurse to input subexpressions.
630 : */
631 54 : if (!foreign_expr_walker((Node *) nt->arg,
632 : glob_cxt, &inner_cxt))
633 0 : return false;
634 :
635 : /* Output is always boolean and so noncollatable. */
636 54 : collation = InvalidOid;
637 54 : state = FDW_COLLATE_NONE;
638 : }
639 54 : break;
640 8 : case T_ArrayExpr:
641 : {
642 8 : ArrayExpr *a = (ArrayExpr *) node;
643 :
644 : /*
645 : * Recurse to input subexpressions.
646 : */
647 8 : if (!foreign_expr_walker((Node *) a->elements,
648 : glob_cxt, &inner_cxt))
649 0 : return false;
650 :
651 : /*
652 : * ArrayExpr must not introduce a collation not derived from
653 : * an input foreign Var (same logic as for a function).
654 : */
655 8 : collation = a->array_collid;
656 8 : if (collation == InvalidOid)
657 8 : state = FDW_COLLATE_NONE;
658 0 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
659 0 : collation == inner_cxt.collation)
660 0 : state = FDW_COLLATE_SAFE;
661 0 : else if (collation == DEFAULT_COLLATION_OID)
662 0 : state = FDW_COLLATE_NONE;
663 : else
664 0 : state = FDW_COLLATE_UNSAFE;
665 : }
666 8 : break;
667 2562 : case T_List:
668 : {
669 2562 : List *l = (List *) node;
670 : ListCell *lc;
671 :
672 : /*
673 : * Recurse to component subexpressions.
674 : */
675 7292 : foreach(lc, l)
676 : {
677 4844 : if (!foreign_expr_walker((Node *) lfirst(lc),
678 : glob_cxt, &inner_cxt))
679 114 : return false;
680 : }
681 :
682 : /*
683 : * When processing a list, collation state just bubbles up
684 : * from the list elements.
685 : */
686 2448 : collation = inner_cxt.collation;
687 2448 : state = inner_cxt.state;
688 :
689 : /* Don't apply exprType() to the list. */
690 2448 : check_type = false;
691 : }
692 2448 : break;
693 458 : case T_Aggref:
694 : {
695 458 : Aggref *agg = (Aggref *) node;
696 : ListCell *lc;
697 :
698 : /* Not safe to pushdown when not in grouping context */
699 458 : if (!IS_UPPER_REL(glob_cxt->foreignrel))
700 0 : return false;
701 :
702 : /* Only non-split aggregates are pushable. */
703 458 : if (agg->aggsplit != AGGSPLIT_SIMPLE)
704 0 : return false;
705 :
706 : /* As usual, it must be shippable. */
707 458 : if (!is_shippable(agg->aggfnoid, ProcedureRelationId, fpinfo))
708 8 : return false;
709 :
710 : /*
711 : * Recurse to input args. aggdirectargs, aggorder and
712 : * aggdistinct are all present in args, so no need to check
713 : * their shippability explicitly.
714 : */
715 828 : foreach(lc, agg->args)
716 : {
717 402 : Node *n = (Node *) lfirst(lc);
718 :
719 : /* If TargetEntry, extract the expression from it */
720 402 : if (IsA(n, TargetEntry))
721 : {
722 402 : TargetEntry *tle = (TargetEntry *) n;
723 :
724 402 : n = (Node *) tle->expr;
725 : }
726 :
727 402 : if (!foreign_expr_walker(n, glob_cxt, &inner_cxt))
728 24 : return false;
729 : }
730 :
731 : /*
732 : * For aggorder elements, check whether the sort operator, if
733 : * specified, is shippable or not.
734 : */
735 426 : if (agg->aggorder)
736 : {
737 : ListCell *lc;
738 :
739 116 : foreach(lc, agg->aggorder)
740 : {
741 64 : SortGroupClause *srt = (SortGroupClause *) lfirst(lc);
742 : Oid sortcoltype;
743 : TypeCacheEntry *typentry;
744 : TargetEntry *tle;
745 :
746 64 : tle = get_sortgroupref_tle(srt->tleSortGroupRef,
747 : agg->args);
748 64 : sortcoltype = exprType((Node *) tle->expr);
749 64 : typentry = lookup_type_cache(sortcoltype,
750 : TYPECACHE_LT_OPR | TYPECACHE_GT_OPR);
751 : /* Check shippability of non-default sort operator. */
752 64 : if (srt->sortop != typentry->lt_opr &&
753 24 : srt->sortop != typentry->gt_opr &&
754 12 : !is_shippable(srt->sortop, OperatorRelationId,
755 : fpinfo))
756 8 : return false;
757 : }
758 : }
759 :
760 : /* Check aggregate filter */
761 418 : if (!foreign_expr_walker((Node *) agg->aggfilter,
762 : glob_cxt, &inner_cxt))
763 4 : return false;
764 :
765 : /*
766 : * If aggregate's input collation is not derived from a
767 : * foreign Var, it can't be sent to remote.
768 : */
769 414 : if (agg->inputcollid == InvalidOid)
770 : /* OK, inputs are all noncollatable */ ;
771 36 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
772 36 : agg->inputcollid != inner_cxt.collation)
773 0 : return false;
774 :
775 : /*
776 : * Detect whether node is introducing a collation not derived
777 : * from a foreign Var. (If so, we just mark it unsafe for now
778 : * rather than immediately returning false, since the parent
779 : * node might not care.)
780 : */
781 414 : collation = agg->aggcollid;
782 414 : if (collation == InvalidOid)
783 412 : state = FDW_COLLATE_NONE;
784 2 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
785 2 : collation == inner_cxt.collation)
786 2 : state = FDW_COLLATE_SAFE;
787 0 : else if (collation == DEFAULT_COLLATION_OID)
788 0 : state = FDW_COLLATE_NONE;
789 : else
790 0 : state = FDW_COLLATE_UNSAFE;
791 : }
792 414 : break;
793 60 : default:
794 :
795 : /*
796 : * If it's anything else, assume it's unsafe. This list can be
797 : * expanded later, but don't forget to add deparse support below.
798 : */
799 60 : return false;
800 : }
801 :
802 : /*
803 : * If result type of given expression is not shippable, it can't be sent
804 : * to remote because it might have incompatible semantics on remote side.
805 : */
806 11888 : if (check_type && !is_shippable(exprType(node), TypeRelationId, fpinfo))
807 50 : return false;
808 :
809 : /*
810 : * Now, merge my collation information into my parent's state.
811 : */
812 11838 : if (state > outer_cxt->state)
813 : {
814 : /* Override previous parent state */
815 574 : outer_cxt->collation = collation;
816 574 : outer_cxt->state = state;
817 : }
818 11264 : else if (state == outer_cxt->state)
819 : {
820 : /* Merge, or detect error if there's a collation conflict */
821 11188 : switch (state)
822 : {
823 11182 : case FDW_COLLATE_NONE:
824 : /* Nothing + nothing is still nothing */
825 11182 : break;
826 4 : case FDW_COLLATE_SAFE:
827 4 : if (collation != outer_cxt->collation)
828 : {
829 : /*
830 : * Non-default collation always beats default.
831 : */
832 0 : if (outer_cxt->collation == DEFAULT_COLLATION_OID)
833 : {
834 : /* Override previous parent state */
835 0 : outer_cxt->collation = collation;
836 : }
837 0 : else if (collation != DEFAULT_COLLATION_OID)
838 : {
839 : /*
840 : * Conflict; show state as indeterminate. We don't
841 : * want to "return false" right away, since parent
842 : * node might not care about collation.
843 : */
844 0 : outer_cxt->state = FDW_COLLATE_UNSAFE;
845 : }
846 : }
847 4 : break;
848 2 : case FDW_COLLATE_UNSAFE:
849 : /* We're still conflicted ... */
850 2 : break;
851 : }
852 76 : }
853 :
854 : /* It looks OK */
855 11838 : return true;
856 : }
857 :
858 : /*
859 : * Returns true if given expr is something we'd have to send the value of
860 : * to the foreign server.
861 : *
862 : * This should return true when the expression is a shippable node that
863 : * deparseExpr would add to context->params_list. Note that we don't care
864 : * if the expression *contains* such a node, only whether one appears at top
865 : * level. We need this to detect cases where setrefs.c would recognize a
866 : * false match between an fdw_exprs item (which came from the params_list)
867 : * and an entry in fdw_scan_tlist (which we're considering putting the given
868 : * expression into).
869 : */
870 : bool
871 502 : is_foreign_param(PlannerInfo *root,
872 : RelOptInfo *baserel,
873 : Expr *expr)
874 : {
875 502 : if (expr == NULL)
876 0 : return false;
877 :
878 502 : switch (nodeTag(expr))
879 : {
880 152 : case T_Var:
881 : {
882 : /* It would have to be sent unless it's a foreign Var */
883 152 : Var *var = (Var *) expr;
884 152 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) (baserel->fdw_private);
885 : Relids relids;
886 :
887 152 : if (IS_UPPER_REL(baserel))
888 152 : relids = fpinfo->outerrel->relids;
889 : else
890 0 : relids = baserel->relids;
891 :
892 152 : if (bms_is_member(var->varno, relids) && var->varlevelsup == 0)
893 152 : return false; /* foreign Var, so not a param */
894 : else
895 0 : return true; /* it'd have to be a param */
896 : break;
897 : }
898 8 : case T_Param:
899 : /* Params always have to be sent to the foreign server */
900 8 : return true;
901 342 : default:
902 342 : break;
903 : }
904 342 : return false;
905 : }
906 :
907 : /*
908 : * Convert type OID + typmod info into a type name we can ship to the remote
909 : * server. Someplace else had better have verified that this type name is
910 : * expected to be known on the remote end.
911 : *
912 : * This is almost just format_type_with_typemod(), except that if left to its
913 : * own devices, that function will make schema-qualification decisions based
914 : * on the local search_path, which is wrong. We must schema-qualify all
915 : * type names that are not in pg_catalog. We assume here that built-in types
916 : * are all in pg_catalog and need not be qualified; otherwise, qualify.
917 : */
918 : static char *
919 854 : deparse_type_name(Oid type_oid, int32 typemod)
920 : {
921 854 : bits16 flags = FORMAT_TYPE_TYPEMOD_GIVEN;
922 :
923 854 : if (!is_builtin(type_oid))
924 0 : flags |= FORMAT_TYPE_FORCE_QUALIFY;
925 :
926 854 : return format_type_extended(type_oid, typemod, flags);
927 : }
928 :
929 : /*
930 : * Build the targetlist for given relation to be deparsed as SELECT clause.
931 : *
932 : * The output targetlist contains the columns that need to be fetched from the
933 : * foreign server for the given relation. If foreignrel is an upper relation,
934 : * then the output targetlist can also contain expressions to be evaluated on
935 : * foreign server.
936 : */
937 : List *
938 1034 : build_tlist_to_deparse(RelOptInfo *foreignrel)
939 : {
940 1034 : List *tlist = NIL;
941 1034 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
942 : ListCell *lc;
943 :
944 : /*
945 : * For an upper relation, we have already built the target list while
946 : * checking shippability, so just return that.
947 : */
948 1034 : if (IS_UPPER_REL(foreignrel))
949 280 : return fpinfo->grouped_tlist;
950 :
951 : /*
952 : * We require columns specified in foreignrel->reltarget->exprs and those
953 : * required for evaluating the local conditions.
954 : */
955 754 : tlist = add_to_flat_tlist(tlist,
956 754 : pull_var_clause((Node *) foreignrel->reltarget->exprs,
957 : PVC_RECURSE_PLACEHOLDERS));
958 790 : foreach(lc, fpinfo->local_conds)
959 : {
960 36 : RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
961 :
962 36 : tlist = add_to_flat_tlist(tlist,
963 36 : pull_var_clause((Node *) rinfo->clause,
964 : PVC_RECURSE_PLACEHOLDERS));
965 : }
966 :
967 754 : return tlist;
968 : }
969 :
970 : /*
971 : * Deparse SELECT statement for given relation into buf.
972 : *
973 : * tlist contains the list of desired columns to be fetched from foreign server.
974 : * For a base relation fpinfo->attrs_used is used to construct SELECT clause,
975 : * hence the tlist is ignored for a base relation.
976 : *
977 : * remote_conds is the list of conditions to be deparsed into the WHERE clause
978 : * (or, in the case of upper relations, into the HAVING clause).
979 : *
980 : * If params_list is not NULL, it receives a list of Params and other-relation
981 : * Vars used in the clauses; these values must be transmitted to the remote
982 : * server as parameter values.
983 : *
984 : * If params_list is NULL, we're generating the query for EXPLAIN purposes,
985 : * so Params and other-relation Vars should be replaced by dummy values.
986 : *
987 : * pathkeys is the list of pathkeys to order the result by.
988 : *
989 : * is_subquery is the flag to indicate whether to deparse the specified
990 : * relation as a subquery.
991 : *
992 : * List of columns selected is returned in retrieved_attrs.
993 : */
994 : void
995 3184 : deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *rel,
996 : List *tlist, List *remote_conds, List *pathkeys,
997 : bool has_final_sort, bool has_limit, bool is_subquery,
998 : List **retrieved_attrs, List **params_list)
999 : {
1000 : deparse_expr_cxt context;
1001 3184 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
1002 : List *quals;
1003 :
1004 : /*
1005 : * We handle relations for foreign tables, joins between those and upper
1006 : * relations.
1007 : */
1008 : Assert(IS_JOIN_REL(rel) || IS_SIMPLE_REL(rel) || IS_UPPER_REL(rel));
1009 :
1010 : /* Fill portions of context common to upper, join and base relation */
1011 3184 : context.buf = buf;
1012 3184 : context.root = root;
1013 3184 : context.foreignrel = rel;
1014 3184 : context.scanrel = IS_UPPER_REL(rel) ? fpinfo->outerrel : rel;
1015 3184 : context.params_list = params_list;
1016 :
1017 : /* Construct SELECT clause */
1018 3184 : deparseSelectSql(tlist, is_subquery, retrieved_attrs, &context);
1019 :
1020 : /*
1021 : * For upper relations, the WHERE clause is built from the remote
1022 : * conditions of the underlying scan relation; otherwise, we can use the
1023 : * supplied list of remote conditions directly.
1024 : */
1025 3184 : if (IS_UPPER_REL(rel))
1026 280 : {
1027 : PgFdwRelationInfo *ofpinfo;
1028 :
1029 280 : ofpinfo = (PgFdwRelationInfo *) fpinfo->outerrel->fdw_private;
1030 280 : quals = ofpinfo->remote_conds;
1031 : }
1032 : else
1033 2904 : quals = remote_conds;
1034 :
1035 : /* Construct FROM and WHERE clauses */
1036 3184 : deparseFromExpr(quals, &context);
1037 :
1038 3184 : if (IS_UPPER_REL(rel))
1039 : {
1040 : /* Append GROUP BY clause */
1041 280 : appendGroupByClause(tlist, &context);
1042 :
1043 : /* Append HAVING clause */
1044 280 : if (remote_conds)
1045 : {
1046 36 : appendStringInfoString(buf, " HAVING ");
1047 36 : appendConditions(remote_conds, &context);
1048 : }
1049 : }
1050 :
1051 : /* Add ORDER BY clause if we found any useful pathkeys */
1052 3184 : if (pathkeys)
1053 922 : appendOrderByClause(pathkeys, has_final_sort, &context);
1054 :
1055 : /* Add LIMIT clause if necessary */
1056 3184 : if (has_limit)
1057 194 : appendLimitClause(&context);
1058 :
1059 : /* Add any necessary FOR UPDATE/SHARE. */
1060 3184 : deparseLockingClause(&context);
1061 3184 : }
1062 :
1063 : /*
1064 : * Construct a simple SELECT statement that retrieves desired columns
1065 : * of the specified foreign table, and append it to "buf". The output
1066 : * contains just "SELECT ... ".
1067 : *
1068 : * We also create an integer List of the columns being retrieved, which is
1069 : * returned to *retrieved_attrs, unless we deparse the specified relation
1070 : * as a subquery.
1071 : *
1072 : * tlist is the list of desired columns. is_subquery is the flag to
1073 : * indicate whether to deparse the specified relation as a subquery.
1074 : * Read prologue of deparseSelectStmtForRel() for details.
1075 : */
1076 : static void
1077 3184 : deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs,
1078 : deparse_expr_cxt *context)
1079 : {
1080 3184 : StringInfo buf = context->buf;
1081 3184 : RelOptInfo *foreignrel = context->foreignrel;
1082 3184 : PlannerInfo *root = context->root;
1083 3184 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1084 :
1085 : /*
1086 : * Construct SELECT list
1087 : */
1088 3184 : appendStringInfoString(buf, "SELECT ");
1089 :
1090 3184 : if (is_subquery)
1091 : {
1092 : /*
1093 : * For a relation that is deparsed as a subquery, emit expressions
1094 : * specified in the relation's reltarget. Note that since this is for
1095 : * the subquery, no need to care about *retrieved_attrs.
1096 : */
1097 56 : deparseSubqueryTargetList(context);
1098 : }
1099 3128 : else if (IS_JOIN_REL(foreignrel) || IS_UPPER_REL(foreignrel))
1100 : {
1101 : /*
1102 : * For a join or upper relation the input tlist gives the list of
1103 : * columns required to be fetched from the foreign server.
1104 : */
1105 1034 : deparseExplicitTargetList(tlist, false, retrieved_attrs, context);
1106 : }
1107 : else
1108 : {
1109 : /*
1110 : * For a base relation fpinfo->attrs_used gives the list of columns
1111 : * required to be fetched from the foreign server.
1112 : */
1113 2094 : RangeTblEntry *rte = planner_rt_fetch(foreignrel->relid, root);
1114 :
1115 : /*
1116 : * Core code already has some lock on each rel being planned, so we
1117 : * can use NoLock here.
1118 : */
1119 2094 : Relation rel = table_open(rte->relid, NoLock);
1120 :
1121 2094 : deparseTargetList(buf, rte, foreignrel->relid, rel, false,
1122 : fpinfo->attrs_used, false, retrieved_attrs);
1123 2094 : table_close(rel, NoLock);
1124 : }
1125 3184 : }
1126 :
1127 : /*
1128 : * Construct a FROM clause and, if needed, a WHERE clause, and append those to
1129 : * "buf".
1130 : *
1131 : * quals is the list of clauses to be included in the WHERE clause.
1132 : * (These may or may not include RestrictInfo decoration.)
1133 : */
1134 : static void
1135 3184 : deparseFromExpr(List *quals, deparse_expr_cxt *context)
1136 : {
1137 3184 : StringInfo buf = context->buf;
1138 3184 : RelOptInfo *scanrel = context->scanrel;
1139 :
1140 : /* For upper relations, scanrel must be either a joinrel or a baserel */
1141 : Assert(!IS_UPPER_REL(context->foreignrel) ||
1142 : IS_JOIN_REL(scanrel) || IS_SIMPLE_REL(scanrel));
1143 :
1144 : /* Construct FROM clause */
1145 3184 : appendStringInfoString(buf, " FROM ");
1146 3184 : deparseFromExprForRel(buf, context->root, scanrel,
1147 3184 : (bms_membership(scanrel->relids) == BMS_MULTIPLE),
1148 : (Index) 0, NULL, context->params_list);
1149 :
1150 : /* Construct WHERE clause */
1151 3184 : if (quals != NIL)
1152 : {
1153 1260 : appendStringInfoString(buf, " WHERE ");
1154 1260 : appendConditions(quals, context);
1155 : }
1156 3184 : }
1157 :
1158 : /*
1159 : * Emit a target list that retrieves the columns specified in attrs_used.
1160 : * This is used for both SELECT and RETURNING targetlists; the is_returning
1161 : * parameter is true only for a RETURNING targetlist.
1162 : *
1163 : * The tlist text is appended to buf, and we also create an integer List
1164 : * of the columns being retrieved, which is returned to *retrieved_attrs.
1165 : *
1166 : * If qualify_col is true, add relation alias before the column name.
1167 : */
1168 : static void
1169 2676 : deparseTargetList(StringInfo buf,
1170 : RangeTblEntry *rte,
1171 : Index rtindex,
1172 : Relation rel,
1173 : bool is_returning,
1174 : Bitmapset *attrs_used,
1175 : bool qualify_col,
1176 : List **retrieved_attrs)
1177 : {
1178 2676 : TupleDesc tupdesc = RelationGetDescr(rel);
1179 : bool have_wholerow;
1180 : bool first;
1181 : int i;
1182 :
1183 2676 : *retrieved_attrs = NIL;
1184 :
1185 : /* If there's a whole-row reference, we'll need all the columns. */
1186 2676 : have_wholerow = bms_is_member(0 - FirstLowInvalidHeapAttributeNumber,
1187 : attrs_used);
1188 :
1189 2676 : first = true;
1190 19488 : for (i = 1; i <= tupdesc->natts; i++)
1191 : {
1192 16812 : Form_pg_attribute attr = TupleDescAttr(tupdesc, i - 1);
1193 :
1194 : /* Ignore dropped attributes. */
1195 16812 : if (attr->attisdropped)
1196 1522 : continue;
1197 :
1198 26704 : if (have_wholerow ||
1199 11414 : bms_is_member(i - FirstLowInvalidHeapAttributeNumber,
1200 : attrs_used))
1201 : {
1202 8894 : if (!first)
1203 6332 : appendStringInfoString(buf, ", ");
1204 2562 : else if (is_returning)
1205 178 : appendStringInfoString(buf, " RETURNING ");
1206 8894 : first = false;
1207 :
1208 8894 : deparseColumnRef(buf, rtindex, i, rte, qualify_col);
1209 :
1210 8894 : *retrieved_attrs = lappend_int(*retrieved_attrs, i);
1211 : }
1212 : }
1213 :
1214 : /*
1215 : * Add ctid if needed. We currently don't support retrieving any other
1216 : * system columns.
1217 : */
1218 2676 : if (bms_is_member(SelfItemPointerAttributeNumber - FirstLowInvalidHeapAttributeNumber,
1219 : attrs_used))
1220 : {
1221 470 : if (!first)
1222 382 : appendStringInfoString(buf, ", ");
1223 88 : else if (is_returning)
1224 0 : appendStringInfoString(buf, " RETURNING ");
1225 470 : first = false;
1226 :
1227 470 : if (qualify_col)
1228 0 : ADD_REL_QUALIFIER(buf, rtindex);
1229 470 : appendStringInfoString(buf, "ctid");
1230 :
1231 470 : *retrieved_attrs = lappend_int(*retrieved_attrs,
1232 : SelfItemPointerAttributeNumber);
1233 : }
1234 :
1235 : /* Don't generate bad syntax if no undropped columns */
1236 2676 : if (first && !is_returning)
1237 14 : appendStringInfoString(buf, "NULL");
1238 2676 : }
1239 :
1240 : /*
1241 : * Deparse the appropriate locking clause (FOR UPDATE or FOR SHARE) for a
1242 : * given relation (context->scanrel).
1243 : */
1244 : static void
1245 3184 : deparseLockingClause(deparse_expr_cxt *context)
1246 : {
1247 3184 : StringInfo buf = context->buf;
1248 3184 : PlannerInfo *root = context->root;
1249 3184 : RelOptInfo *rel = context->scanrel;
1250 3184 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
1251 3184 : int relid = -1;
1252 :
1253 7350 : while ((relid = bms_next_member(rel->relids, relid)) >= 0)
1254 : {
1255 : /*
1256 : * Ignore relation if it appears in a lower subquery. Locking clause
1257 : * for such a relation is included in the subquery if necessary.
1258 : */
1259 4166 : if (bms_is_member(relid, fpinfo->lower_subquery_rels))
1260 64 : continue;
1261 :
1262 : /*
1263 : * Add FOR UPDATE/SHARE if appropriate. We apply locking during the
1264 : * initial row fetch, rather than later on as is done for local
1265 : * tables. The extra roundtrips involved in trying to duplicate the
1266 : * local semantics exactly don't seem worthwhile (see also comments
1267 : * for RowMarkType).
1268 : *
1269 : * Note: because we actually run the query as a cursor, this assumes
1270 : * that DECLARE CURSOR ... FOR UPDATE is supported, which it isn't
1271 : * before 8.3.
1272 : */
1273 4102 : if (relid == root->parse->resultRelation &&
1274 472 : (root->parse->commandType == CMD_UPDATE ||
1275 196 : root->parse->commandType == CMD_DELETE))
1276 : {
1277 : /* Relation is UPDATE/DELETE target, so use FOR UPDATE */
1278 472 : appendStringInfoString(buf, " FOR UPDATE");
1279 :
1280 : /* Add the relation alias if we are here for a join relation */
1281 556 : if (IS_JOIN_REL(rel))
1282 84 : appendStringInfo(buf, " OF %s%d", REL_ALIAS_PREFIX, relid);
1283 : }
1284 : else
1285 : {
1286 3630 : PlanRowMark *rc = get_plan_rowmark(root->rowMarks, relid);
1287 :
1288 3630 : if (rc)
1289 : {
1290 : /*
1291 : * Relation is specified as a FOR UPDATE/SHARE target, so
1292 : * handle that. (But we could also see LCS_NONE, meaning this
1293 : * isn't a target relation after all.)
1294 : *
1295 : * For now, just ignore any [NO] KEY specification, since (a)
1296 : * it's not clear what that means for a remote table that we
1297 : * don't have complete information about, and (b) it wouldn't
1298 : * work anyway on older remote servers. Likewise, we don't
1299 : * worry about NOWAIT.
1300 : */
1301 588 : switch (rc->strength)
1302 : {
1303 292 : case LCS_NONE:
1304 : /* No locking needed */
1305 292 : break;
1306 68 : case LCS_FORKEYSHARE:
1307 : case LCS_FORSHARE:
1308 68 : appendStringInfoString(buf, " FOR SHARE");
1309 68 : break;
1310 228 : case LCS_FORNOKEYUPDATE:
1311 : case LCS_FORUPDATE:
1312 228 : appendStringInfoString(buf, " FOR UPDATE");
1313 228 : break;
1314 : }
1315 :
1316 : /* Add the relation alias if we are here for a join relation */
1317 588 : if (bms_membership(rel->relids) == BMS_MULTIPLE &&
1318 356 : rc->strength != LCS_NONE)
1319 208 : appendStringInfo(buf, " OF %s%d", REL_ALIAS_PREFIX, relid);
1320 : }
1321 : }
1322 : }
1323 3184 : }
1324 :
1325 : /*
1326 : * Deparse conditions from the provided list and append them to buf.
1327 : *
1328 : * The conditions in the list are assumed to be ANDed. This function is used to
1329 : * deparse WHERE clauses, JOIN .. ON clauses and HAVING clauses.
1330 : *
1331 : * Depending on the caller, the list elements might be either RestrictInfos
1332 : * or bare clauses.
1333 : */
1334 : static void
1335 2328 : appendConditions(List *exprs, deparse_expr_cxt *context)
1336 : {
1337 : int nestlevel;
1338 : ListCell *lc;
1339 2328 : bool is_first = true;
1340 2328 : StringInfo buf = context->buf;
1341 :
1342 : /* Make sure any constants in the exprs are printed portably */
1343 2328 : nestlevel = set_transmission_modes();
1344 :
1345 5312 : foreach(lc, exprs)
1346 : {
1347 2984 : Expr *expr = (Expr *) lfirst(lc);
1348 :
1349 : /* Extract clause from RestrictInfo, if required */
1350 2984 : if (IsA(expr, RestrictInfo))
1351 2454 : expr = ((RestrictInfo *) expr)->clause;
1352 :
1353 : /* Connect expressions with "AND" and parenthesize each condition. */
1354 2984 : if (!is_first)
1355 656 : appendStringInfoString(buf, " AND ");
1356 :
1357 2984 : appendStringInfoChar(buf, '(');
1358 2984 : deparseExpr(expr, context);
1359 2984 : appendStringInfoChar(buf, ')');
1360 :
1361 2984 : is_first = false;
1362 : }
1363 :
1364 2328 : reset_transmission_modes(nestlevel);
1365 2328 : }
1366 :
1367 : /* Output join name for given join type */
1368 : const char *
1369 1408 : get_jointype_name(JoinType jointype)
1370 : {
1371 1408 : switch (jointype)
1372 : {
1373 828 : case JOIN_INNER:
1374 828 : return "INNER";
1375 :
1376 364 : case JOIN_LEFT:
1377 364 : return "LEFT";
1378 :
1379 0 : case JOIN_RIGHT:
1380 0 : return "RIGHT";
1381 :
1382 216 : case JOIN_FULL:
1383 216 : return "FULL";
1384 :
1385 0 : default:
1386 : /* Shouldn't come here, but protect from buggy code. */
1387 0 : elog(ERROR, "unsupported join type %d", jointype);
1388 : }
1389 :
1390 : /* Keep compiler happy */
1391 : return NULL;
1392 : }
1393 :
1394 : /*
1395 : * Deparse given targetlist and append it to context->buf.
1396 : *
1397 : * tlist is list of TargetEntry's which in turn contain Var nodes.
1398 : *
1399 : * retrieved_attrs is the list of continuously increasing integers starting
1400 : * from 1. It has same number of entries as tlist.
1401 : *
1402 : * This is used for both SELECT and RETURNING targetlists; the is_returning
1403 : * parameter is true only for a RETURNING targetlist.
1404 : */
1405 : static void
1406 1058 : deparseExplicitTargetList(List *tlist,
1407 : bool is_returning,
1408 : List **retrieved_attrs,
1409 : deparse_expr_cxt *context)
1410 : {
1411 : ListCell *lc;
1412 1058 : StringInfo buf = context->buf;
1413 1058 : int i = 0;
1414 :
1415 1058 : *retrieved_attrs = NIL;
1416 :
1417 5180 : foreach(lc, tlist)
1418 : {
1419 4122 : TargetEntry *tle = lfirst_node(TargetEntry, lc);
1420 :
1421 4122 : if (i > 0)
1422 3080 : appendStringInfoString(buf, ", ");
1423 1042 : else if (is_returning)
1424 12 : appendStringInfoString(buf, " RETURNING ");
1425 :
1426 4122 : deparseExpr((Expr *) tle->expr, context);
1427 :
1428 4122 : *retrieved_attrs = lappend_int(*retrieved_attrs, i + 1);
1429 4122 : i++;
1430 : }
1431 :
1432 1058 : if (i == 0 && !is_returning)
1433 4 : appendStringInfoString(buf, "NULL");
1434 1058 : }
1435 :
1436 : /*
1437 : * Emit expressions specified in the given relation's reltarget.
1438 : *
1439 : * This is used for deparsing the given relation as a subquery.
1440 : */
1441 : static void
1442 56 : deparseSubqueryTargetList(deparse_expr_cxt *context)
1443 : {
1444 56 : StringInfo buf = context->buf;
1445 56 : RelOptInfo *foreignrel = context->foreignrel;
1446 : bool first;
1447 : ListCell *lc;
1448 :
1449 : /* Should only be called in these cases. */
1450 : Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
1451 :
1452 56 : first = true;
1453 120 : foreach(lc, foreignrel->reltarget->exprs)
1454 : {
1455 64 : Node *node = (Node *) lfirst(lc);
1456 :
1457 64 : if (!first)
1458 16 : appendStringInfoString(buf, ", ");
1459 64 : first = false;
1460 :
1461 64 : deparseExpr((Expr *) node, context);
1462 : }
1463 :
1464 : /* Don't generate bad syntax if no expressions */
1465 56 : if (first)
1466 8 : appendStringInfoString(buf, "NULL");
1467 56 : }
1468 :
1469 : /*
1470 : * Construct FROM clause for given relation
1471 : *
1472 : * The function constructs ... JOIN ... ON ... for join relation. For a base
1473 : * relation it just returns schema-qualified tablename, with the appropriate
1474 : * alias if so requested.
1475 : *
1476 : * 'ignore_rel' is either zero or the RT index of a target relation. In the
1477 : * latter case the function constructs FROM clause of UPDATE or USING clause
1478 : * of DELETE; it deparses the join relation as if the relation never contained
1479 : * the target relation, and creates a List of conditions to be deparsed into
1480 : * the top-level WHERE clause, which is returned to *ignore_conds.
1481 : */
1482 : static void
1483 5140 : deparseFromExprForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
1484 : bool use_alias, Index ignore_rel, List **ignore_conds,
1485 : List **params_list)
1486 : {
1487 5140 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1488 :
1489 5140 : if (IS_JOIN_REL(foreignrel))
1490 982 : {
1491 : StringInfoData join_sql_o;
1492 : StringInfoData join_sql_i;
1493 1006 : RelOptInfo *outerrel = fpinfo->outerrel;
1494 1006 : RelOptInfo *innerrel = fpinfo->innerrel;
1495 1006 : bool outerrel_is_target = false;
1496 1006 : bool innerrel_is_target = false;
1497 :
1498 1006 : if (ignore_rel > 0 && bms_is_member(ignore_rel, foreignrel->relids))
1499 : {
1500 : /*
1501 : * If this is an inner join, add joinclauses to *ignore_conds and
1502 : * set it to empty so that those can be deparsed into the WHERE
1503 : * clause. Note that since the target relation can never be
1504 : * within the nullable side of an outer join, those could safely
1505 : * be pulled up into the WHERE clause (see foreign_join_ok()).
1506 : * Note also that since the target relation is only inner-joined
1507 : * to any other relation in the query, all conditions in the join
1508 : * tree mentioning the target relation could be deparsed into the
1509 : * WHERE clause by doing this recursively.
1510 : */
1511 32 : if (fpinfo->jointype == JOIN_INNER)
1512 : {
1513 56 : *ignore_conds = list_concat(*ignore_conds,
1514 28 : fpinfo->joinclauses);
1515 28 : fpinfo->joinclauses = NIL;
1516 : }
1517 :
1518 : /*
1519 : * Check if either of the input relations is the target relation.
1520 : */
1521 32 : if (outerrel->relid == ignore_rel)
1522 24 : outerrel_is_target = true;
1523 8 : else if (innerrel->relid == ignore_rel)
1524 0 : innerrel_is_target = true;
1525 : }
1526 :
1527 : /* Deparse outer relation if not the target relation. */
1528 1006 : if (!outerrel_is_target)
1529 : {
1530 982 : initStringInfo(&join_sql_o);
1531 982 : deparseRangeTblRef(&join_sql_o, root, outerrel,
1532 982 : fpinfo->make_outerrel_subquery,
1533 : ignore_rel, ignore_conds, params_list);
1534 :
1535 : /*
1536 : * If inner relation is the target relation, skip deparsing it.
1537 : * Note that since the join of the target relation with any other
1538 : * relation in the query is an inner join and can never be within
1539 : * the nullable side of an outer join, the join could be
1540 : * interchanged with higher-level joins (cf. identity 1 on outer
1541 : * join reordering shown in src/backend/optimizer/README), which
1542 : * means it's safe to skip the target-relation deparsing here.
1543 : */
1544 982 : if (innerrel_is_target)
1545 : {
1546 : Assert(fpinfo->jointype == JOIN_INNER);
1547 : Assert(fpinfo->joinclauses == NIL);
1548 0 : appendBinaryStringInfo(buf, join_sql_o.data, join_sql_o.len);
1549 24 : return;
1550 : }
1551 : }
1552 :
1553 : /* Deparse inner relation if not the target relation. */
1554 1006 : if (!innerrel_is_target)
1555 : {
1556 1006 : initStringInfo(&join_sql_i);
1557 1006 : deparseRangeTblRef(&join_sql_i, root, innerrel,
1558 1006 : fpinfo->make_innerrel_subquery,
1559 : ignore_rel, ignore_conds, params_list);
1560 :
1561 : /*
1562 : * If outer relation is the target relation, skip deparsing it.
1563 : * See the above note about safety.
1564 : */
1565 1006 : if (outerrel_is_target)
1566 : {
1567 : Assert(fpinfo->jointype == JOIN_INNER);
1568 : Assert(fpinfo->joinclauses == NIL);
1569 24 : appendBinaryStringInfo(buf, join_sql_i.data, join_sql_i.len);
1570 24 : return;
1571 : }
1572 : }
1573 :
1574 : /* Neither of the relations is the target relation. */
1575 : Assert(!outerrel_is_target && !innerrel_is_target);
1576 :
1577 : /*
1578 : * For a join relation FROM clause entry is deparsed as
1579 : *
1580 : * ((outer relation) <join type> (inner relation) ON (joinclauses))
1581 : */
1582 982 : appendStringInfo(buf, "(%s %s JOIN %s ON ", join_sql_o.data,
1583 : get_jointype_name(fpinfo->jointype), join_sql_i.data);
1584 :
1585 : /* Append join clause; (TRUE) if no join clause */
1586 982 : if (fpinfo->joinclauses)
1587 : {
1588 : deparse_expr_cxt context;
1589 :
1590 950 : context.buf = buf;
1591 950 : context.foreignrel = foreignrel;
1592 950 : context.scanrel = foreignrel;
1593 950 : context.root = root;
1594 950 : context.params_list = params_list;
1595 :
1596 950 : appendStringInfoChar(buf, '(');
1597 950 : appendConditions(fpinfo->joinclauses, &context);
1598 950 : appendStringInfoChar(buf, ')');
1599 : }
1600 : else
1601 32 : appendStringInfoString(buf, "(TRUE)");
1602 :
1603 : /* End the FROM clause entry. */
1604 982 : appendStringInfoChar(buf, ')');
1605 : }
1606 : else
1607 : {
1608 4134 : RangeTblEntry *rte = planner_rt_fetch(foreignrel->relid, root);
1609 :
1610 : /*
1611 : * Core code already has some lock on each rel being planned, so we
1612 : * can use NoLock here.
1613 : */
1614 4134 : Relation rel = table_open(rte->relid, NoLock);
1615 :
1616 4134 : deparseRelation(buf, rel);
1617 :
1618 : /*
1619 : * Add a unique alias to avoid any conflict in relation names due to
1620 : * pulled up subqueries in the query being built for a pushed down
1621 : * join.
1622 : */
1623 4134 : if (use_alias)
1624 1744 : appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, foreignrel->relid);
1625 :
1626 4134 : table_close(rel, NoLock);
1627 : }
1628 : }
1629 :
1630 : /*
1631 : * Append FROM clause entry for the given relation into buf.
1632 : */
1633 : static void
1634 1988 : deparseRangeTblRef(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
1635 : bool make_subquery, Index ignore_rel, List **ignore_conds,
1636 : List **params_list)
1637 : {
1638 1988 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1639 :
1640 : /* Should only be called in these cases. */
1641 : Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
1642 :
1643 : Assert(fpinfo->local_conds == NIL);
1644 :
1645 : /* If make_subquery is true, deparse the relation as a subquery. */
1646 1988 : if (make_subquery)
1647 : {
1648 : List *retrieved_attrs;
1649 : int ncols;
1650 :
1651 : /*
1652 : * The given relation shouldn't contain the target relation, because
1653 : * this should only happen for input relations for a full join, and
1654 : * such relations can never contain an UPDATE/DELETE target.
1655 : */
1656 : Assert(ignore_rel == 0 ||
1657 : !bms_is_member(ignore_rel, foreignrel->relids));
1658 :
1659 : /* Deparse the subquery representing the relation. */
1660 56 : appendStringInfoChar(buf, '(');
1661 56 : deparseSelectStmtForRel(buf, root, foreignrel, NIL,
1662 : fpinfo->remote_conds, NIL,
1663 : false, false, true,
1664 : &retrieved_attrs, params_list);
1665 56 : appendStringInfoChar(buf, ')');
1666 :
1667 : /* Append the relation alias. */
1668 56 : appendStringInfo(buf, " %s%d", SUBQUERY_REL_ALIAS_PREFIX,
1669 : fpinfo->relation_index);
1670 :
1671 : /*
1672 : * Append the column aliases if needed. Note that the subquery emits
1673 : * expressions specified in the relation's reltarget (see
1674 : * deparseSubqueryTargetList).
1675 : */
1676 56 : ncols = list_length(foreignrel->reltarget->exprs);
1677 56 : if (ncols > 0)
1678 : {
1679 : int i;
1680 :
1681 48 : appendStringInfoChar(buf, '(');
1682 112 : for (i = 1; i <= ncols; i++)
1683 : {
1684 64 : if (i > 1)
1685 16 : appendStringInfoString(buf, ", ");
1686 :
1687 64 : appendStringInfo(buf, "%s%d", SUBQUERY_COL_ALIAS_PREFIX, i);
1688 : }
1689 48 : appendStringInfoChar(buf, ')');
1690 : }
1691 : }
1692 : else
1693 1932 : deparseFromExprForRel(buf, root, foreignrel, true, ignore_rel,
1694 : ignore_conds, params_list);
1695 1988 : }
1696 :
1697 : /*
1698 : * deparse remote INSERT statement
1699 : *
1700 : * The statement text is appended to buf, and we also create an integer List
1701 : * of the columns being retrieved by WITH CHECK OPTION or RETURNING (if any),
1702 : * which is returned to *retrieved_attrs.
1703 : */
1704 : void
1705 172 : deparseInsertSql(StringInfo buf, RangeTblEntry *rte,
1706 : Index rtindex, Relation rel,
1707 : List *targetAttrs, bool doNothing,
1708 : List *withCheckOptionList, List *returningList,
1709 : List **retrieved_attrs)
1710 : {
1711 : AttrNumber pindex;
1712 : bool first;
1713 : ListCell *lc;
1714 :
1715 172 : appendStringInfoString(buf, "INSERT INTO ");
1716 172 : deparseRelation(buf, rel);
1717 :
1718 172 : if (targetAttrs)
1719 : {
1720 172 : appendStringInfoChar(buf, '(');
1721 :
1722 172 : first = true;
1723 730 : foreach(lc, targetAttrs)
1724 : {
1725 558 : int attnum = lfirst_int(lc);
1726 :
1727 558 : if (!first)
1728 386 : appendStringInfoString(buf, ", ");
1729 558 : first = false;
1730 :
1731 558 : deparseColumnRef(buf, rtindex, attnum, rte, false);
1732 : }
1733 :
1734 172 : appendStringInfoString(buf, ") VALUES (");
1735 :
1736 172 : pindex = 1;
1737 172 : first = true;
1738 730 : foreach(lc, targetAttrs)
1739 : {
1740 558 : if (!first)
1741 386 : appendStringInfoString(buf, ", ");
1742 558 : first = false;
1743 :
1744 558 : appendStringInfo(buf, "$%d", pindex);
1745 558 : pindex++;
1746 : }
1747 :
1748 172 : appendStringInfoChar(buf, ')');
1749 : }
1750 : else
1751 0 : appendStringInfoString(buf, " DEFAULT VALUES");
1752 :
1753 172 : if (doNothing)
1754 6 : appendStringInfoString(buf, " ON CONFLICT DO NOTHING");
1755 :
1756 172 : deparseReturningList(buf, rte, rtindex, rel,
1757 172 : rel->trigdesc && rel->trigdesc->trig_insert_after_row,
1758 : withCheckOptionList, returningList, retrieved_attrs);
1759 172 : }
1760 :
1761 : /*
1762 : * deparse remote UPDATE statement
1763 : *
1764 : * The statement text is appended to buf, and we also create an integer List
1765 : * of the columns being retrieved by WITH CHECK OPTION or RETURNING (if any),
1766 : * which is returned to *retrieved_attrs.
1767 : */
1768 : void
1769 86 : deparseUpdateSql(StringInfo buf, RangeTblEntry *rte,
1770 : Index rtindex, Relation rel,
1771 : List *targetAttrs,
1772 : List *withCheckOptionList, List *returningList,
1773 : List **retrieved_attrs)
1774 : {
1775 : AttrNumber pindex;
1776 : bool first;
1777 : ListCell *lc;
1778 :
1779 86 : appendStringInfoString(buf, "UPDATE ");
1780 86 : deparseRelation(buf, rel);
1781 86 : appendStringInfoString(buf, " SET ");
1782 :
1783 86 : pindex = 2; /* ctid is always the first param */
1784 86 : first = true;
1785 212 : foreach(lc, targetAttrs)
1786 : {
1787 126 : int attnum = lfirst_int(lc);
1788 :
1789 126 : if (!first)
1790 40 : appendStringInfoString(buf, ", ");
1791 126 : first = false;
1792 :
1793 126 : deparseColumnRef(buf, rtindex, attnum, rte, false);
1794 126 : appendStringInfo(buf, " = $%d", pindex);
1795 126 : pindex++;
1796 : }
1797 86 : appendStringInfoString(buf, " WHERE ctid = $1");
1798 :
1799 86 : deparseReturningList(buf, rte, rtindex, rel,
1800 86 : rel->trigdesc && rel->trigdesc->trig_update_after_row,
1801 : withCheckOptionList, returningList, retrieved_attrs);
1802 86 : }
1803 :
1804 : /*
1805 : * deparse remote UPDATE statement
1806 : *
1807 : * 'buf' is the output buffer to append the statement to
1808 : * 'rtindex' is the RT index of the associated target relation
1809 : * 'rel' is the relation descriptor for the target relation
1810 : * 'foreignrel' is the RelOptInfo for the target relation or the join relation
1811 : * containing all base relations in the query
1812 : * 'targetlist' is the tlist of the underlying foreign-scan plan node
1813 : * 'targetAttrs' is the target columns of the UPDATE
1814 : * 'remote_conds' is the qual clauses that must be evaluated remotely
1815 : * '*params_list' is an output list of exprs that will become remote Params
1816 : * 'returningList' is the RETURNING targetlist
1817 : * '*retrieved_attrs' is an output list of integers of columns being retrieved
1818 : * by RETURNING (if any)
1819 : */
1820 : void
1821 82 : deparseDirectUpdateSql(StringInfo buf, PlannerInfo *root,
1822 : Index rtindex, Relation rel,
1823 : RelOptInfo *foreignrel,
1824 : List *targetlist,
1825 : List *targetAttrs,
1826 : List *remote_conds,
1827 : List **params_list,
1828 : List *returningList,
1829 : List **retrieved_attrs)
1830 : {
1831 : deparse_expr_cxt context;
1832 : int nestlevel;
1833 : bool first;
1834 : ListCell *lc;
1835 82 : RangeTblEntry *rte = planner_rt_fetch(rtindex, root);
1836 :
1837 : /* Set up context struct for recursion */
1838 82 : context.root = root;
1839 82 : context.foreignrel = foreignrel;
1840 82 : context.scanrel = foreignrel;
1841 82 : context.buf = buf;
1842 82 : context.params_list = params_list;
1843 :
1844 82 : appendStringInfoString(buf, "UPDATE ");
1845 82 : deparseRelation(buf, rel);
1846 82 : if (foreignrel->reloptkind == RELOPT_JOINREL)
1847 12 : appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, rtindex);
1848 82 : appendStringInfoString(buf, " SET ");
1849 :
1850 : /* Make sure any constants in the exprs are printed portably */
1851 82 : nestlevel = set_transmission_modes();
1852 :
1853 82 : first = true;
1854 180 : foreach(lc, targetAttrs)
1855 : {
1856 98 : int attnum = lfirst_int(lc);
1857 98 : TargetEntry *tle = get_tle_by_resno(targetlist, attnum);
1858 :
1859 98 : if (!tle)
1860 0 : elog(ERROR, "attribute number %d not found in UPDATE targetlist",
1861 : attnum);
1862 :
1863 98 : if (!first)
1864 16 : appendStringInfoString(buf, ", ");
1865 98 : first = false;
1866 :
1867 98 : deparseColumnRef(buf, rtindex, attnum, rte, false);
1868 98 : appendStringInfoString(buf, " = ");
1869 98 : deparseExpr((Expr *) tle->expr, &context);
1870 : }
1871 :
1872 82 : reset_transmission_modes(nestlevel);
1873 :
1874 82 : if (foreignrel->reloptkind == RELOPT_JOINREL)
1875 : {
1876 12 : List *ignore_conds = NIL;
1877 :
1878 12 : appendStringInfoString(buf, " FROM ");
1879 12 : deparseFromExprForRel(buf, root, foreignrel, true, rtindex,
1880 : &ignore_conds, params_list);
1881 12 : remote_conds = list_concat(remote_conds, ignore_conds);
1882 : }
1883 :
1884 82 : if (remote_conds)
1885 : {
1886 54 : appendStringInfoString(buf, " WHERE ");
1887 54 : appendConditions(remote_conds, &context);
1888 : }
1889 :
1890 82 : if (foreignrel->reloptkind == RELOPT_JOINREL)
1891 12 : deparseExplicitTargetList(returningList, true, retrieved_attrs,
1892 : &context);
1893 : else
1894 70 : deparseReturningList(buf, rte, rtindex, rel, false,
1895 : NIL, returningList, retrieved_attrs);
1896 82 : }
1897 :
1898 : /*
1899 : * deparse remote DELETE statement
1900 : *
1901 : * The statement text is appended to buf, and we also create an integer List
1902 : * of the columns being retrieved by RETURNING (if any), which is returned
1903 : * to *retrieved_attrs.
1904 : */
1905 : void
1906 20 : deparseDeleteSql(StringInfo buf, RangeTblEntry *rte,
1907 : Index rtindex, Relation rel,
1908 : List *returningList,
1909 : List **retrieved_attrs)
1910 : {
1911 20 : appendStringInfoString(buf, "DELETE FROM ");
1912 20 : deparseRelation(buf, rel);
1913 20 : appendStringInfoString(buf, " WHERE ctid = $1");
1914 :
1915 20 : deparseReturningList(buf, rte, rtindex, rel,
1916 20 : rel->trigdesc && rel->trigdesc->trig_delete_after_row,
1917 : NIL, returningList, retrieved_attrs);
1918 20 : }
1919 :
1920 : /*
1921 : * deparse remote DELETE statement
1922 : *
1923 : * 'buf' is the output buffer to append the statement to
1924 : * 'rtindex' is the RT index of the associated target relation
1925 : * 'rel' is the relation descriptor for the target relation
1926 : * 'foreignrel' is the RelOptInfo for the target relation or the join relation
1927 : * containing all base relations in the query
1928 : * 'remote_conds' is the qual clauses that must be evaluated remotely
1929 : * '*params_list' is an output list of exprs that will become remote Params
1930 : * 'returningList' is the RETURNING targetlist
1931 : * '*retrieved_attrs' is an output list of integers of columns being retrieved
1932 : * by RETURNING (if any)
1933 : */
1934 : void
1935 84 : deparseDirectDeleteSql(StringInfo buf, PlannerInfo *root,
1936 : Index rtindex, Relation rel,
1937 : RelOptInfo *foreignrel,
1938 : List *remote_conds,
1939 : List **params_list,
1940 : List *returningList,
1941 : List **retrieved_attrs)
1942 : {
1943 : deparse_expr_cxt context;
1944 :
1945 : /* Set up context struct for recursion */
1946 84 : context.root = root;
1947 84 : context.foreignrel = foreignrel;
1948 84 : context.scanrel = foreignrel;
1949 84 : context.buf = buf;
1950 84 : context.params_list = params_list;
1951 :
1952 84 : appendStringInfoString(buf, "DELETE FROM ");
1953 84 : deparseRelation(buf, rel);
1954 84 : if (foreignrel->reloptkind == RELOPT_JOINREL)
1955 12 : appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, rtindex);
1956 :
1957 84 : if (foreignrel->reloptkind == RELOPT_JOINREL)
1958 : {
1959 12 : List *ignore_conds = NIL;
1960 :
1961 12 : appendStringInfoString(buf, " USING ");
1962 12 : deparseFromExprForRel(buf, root, foreignrel, true, rtindex,
1963 : &ignore_conds, params_list);
1964 12 : remote_conds = list_concat(remote_conds, ignore_conds);
1965 : }
1966 :
1967 84 : if (remote_conds)
1968 : {
1969 28 : appendStringInfoString(buf, " WHERE ");
1970 28 : appendConditions(remote_conds, &context);
1971 : }
1972 :
1973 84 : if (foreignrel->reloptkind == RELOPT_JOINREL)
1974 12 : deparseExplicitTargetList(returningList, true, retrieved_attrs,
1975 : &context);
1976 : else
1977 72 : deparseReturningList(buf, planner_rt_fetch(rtindex, root),
1978 : rtindex, rel, false,
1979 : NIL, returningList, retrieved_attrs);
1980 84 : }
1981 :
1982 : /*
1983 : * Add a RETURNING clause, if needed, to an INSERT/UPDATE/DELETE.
1984 : */
1985 : static void
1986 420 : deparseReturningList(StringInfo buf, RangeTblEntry *rte,
1987 : Index rtindex, Relation rel,
1988 : bool trig_after_row,
1989 : List *withCheckOptionList,
1990 : List *returningList,
1991 : List **retrieved_attrs)
1992 : {
1993 420 : Bitmapset *attrs_used = NULL;
1994 :
1995 420 : if (trig_after_row)
1996 : {
1997 : /* whole-row reference acquires all non-system columns */
1998 48 : attrs_used =
1999 48 : bms_make_singleton(0 - FirstLowInvalidHeapAttributeNumber);
2000 : }
2001 :
2002 420 : if (withCheckOptionList != NIL)
2003 : {
2004 : /*
2005 : * We need the attrs, non-system and system, mentioned in the local
2006 : * query's WITH CHECK OPTION list.
2007 : *
2008 : * Note: we do this to ensure that WCO constraints will be evaluated
2009 : * on the data actually inserted/updated on the remote side, which
2010 : * might differ from the data supplied by the core code, for example
2011 : * as a result of remote triggers.
2012 : */
2013 28 : pull_varattnos((Node *) withCheckOptionList, rtindex,
2014 : &attrs_used);
2015 : }
2016 :
2017 420 : if (returningList != NIL)
2018 : {
2019 : /*
2020 : * We need the attrs, non-system and system, mentioned in the local
2021 : * query's RETURNING list.
2022 : */
2023 116 : pull_varattnos((Node *) returningList, rtindex,
2024 : &attrs_used);
2025 : }
2026 :
2027 420 : if (attrs_used != NULL)
2028 190 : deparseTargetList(buf, rte, rtindex, rel, true, attrs_used, false,
2029 : retrieved_attrs);
2030 : else
2031 230 : *retrieved_attrs = NIL;
2032 420 : }
2033 :
2034 : /*
2035 : * Construct SELECT statement to acquire size in blocks of given relation.
2036 : *
2037 : * Note: we use local definition of block size, not remote definition.
2038 : * This is perhaps debatable.
2039 : *
2040 : * Note: pg_relation_size() exists in 8.1 and later.
2041 : */
2042 : void
2043 48 : deparseAnalyzeSizeSql(StringInfo buf, Relation rel)
2044 : {
2045 : StringInfoData relname;
2046 :
2047 : /* We'll need the remote relation name as a literal. */
2048 48 : initStringInfo(&relname);
2049 48 : deparseRelation(&relname, rel);
2050 :
2051 48 : appendStringInfoString(buf, "SELECT pg_catalog.pg_relation_size(");
2052 48 : deparseStringLiteral(buf, relname.data);
2053 48 : appendStringInfo(buf, "::pg_catalog.regclass) / %d", BLCKSZ);
2054 48 : }
2055 :
2056 : /*
2057 : * Construct SELECT statement to acquire sample rows of given relation.
2058 : *
2059 : * SELECT command is appended to buf, and list of columns retrieved
2060 : * is returned to *retrieved_attrs.
2061 : */
2062 : void
2063 48 : deparseAnalyzeSql(StringInfo buf, Relation rel, List **retrieved_attrs)
2064 : {
2065 48 : Oid relid = RelationGetRelid(rel);
2066 48 : TupleDesc tupdesc = RelationGetDescr(rel);
2067 : int i;
2068 : char *colname;
2069 : List *options;
2070 : ListCell *lc;
2071 48 : bool first = true;
2072 :
2073 48 : *retrieved_attrs = NIL;
2074 :
2075 48 : appendStringInfoString(buf, "SELECT ");
2076 212 : for (i = 0; i < tupdesc->natts; i++)
2077 : {
2078 : /* Ignore dropped columns. */
2079 164 : if (TupleDescAttr(tupdesc, i)->attisdropped)
2080 4 : continue;
2081 :
2082 160 : if (!first)
2083 112 : appendStringInfoString(buf, ", ");
2084 160 : first = false;
2085 :
2086 : /* Use attribute name or column_name option. */
2087 160 : colname = NameStr(TupleDescAttr(tupdesc, i)->attname);
2088 160 : options = GetForeignColumnOptions(relid, i + 1);
2089 :
2090 160 : foreach(lc, options)
2091 : {
2092 4 : DefElem *def = (DefElem *) lfirst(lc);
2093 :
2094 4 : if (strcmp(def->defname, "column_name") == 0)
2095 : {
2096 4 : colname = defGetString(def);
2097 4 : break;
2098 : }
2099 : }
2100 :
2101 160 : appendStringInfoString(buf, quote_identifier(colname));
2102 :
2103 160 : *retrieved_attrs = lappend_int(*retrieved_attrs, i + 1);
2104 : }
2105 :
2106 : /* Don't generate bad syntax for zero-column relation. */
2107 48 : if (first)
2108 0 : appendStringInfoString(buf, "NULL");
2109 :
2110 : /*
2111 : * Construct FROM clause
2112 : */
2113 48 : appendStringInfoString(buf, " FROM ");
2114 48 : deparseRelation(buf, rel);
2115 48 : }
2116 :
2117 : /*
2118 : * Construct name to use for given column, and emit it into buf.
2119 : * If it has a column_name FDW option, use that instead of attribute name.
2120 : *
2121 : * If qualify_col is true, qualify column name with the alias of relation.
2122 : */
2123 : static void
2124 18960 : deparseColumnRef(StringInfo buf, int varno, int varattno, RangeTblEntry *rte,
2125 : bool qualify_col)
2126 : {
2127 : /* We support fetching the remote side's CTID and OID. */
2128 18960 : if (varattno == SelfItemPointerAttributeNumber)
2129 : {
2130 96 : if (qualify_col)
2131 92 : ADD_REL_QUALIFIER(buf, varno);
2132 96 : appendStringInfoString(buf, "ctid");
2133 : }
2134 18864 : else if (varattno < 0)
2135 : {
2136 : /*
2137 : * All other system attributes are fetched as 0, except for table OID,
2138 : * which is fetched as the local table OID. However, we must be
2139 : * careful; the table could be beneath an outer join, in which case it
2140 : * must go to NULL whenever the rest of the row does.
2141 : */
2142 0 : Oid fetchval = 0;
2143 :
2144 0 : if (varattno == TableOidAttributeNumber)
2145 0 : fetchval = rte->relid;
2146 :
2147 0 : if (qualify_col)
2148 : {
2149 0 : appendStringInfoString(buf, "CASE WHEN (");
2150 0 : ADD_REL_QUALIFIER(buf, varno);
2151 0 : appendStringInfo(buf, "*)::text IS NOT NULL THEN %u END", fetchval);
2152 : }
2153 : else
2154 0 : appendStringInfo(buf, "%u", fetchval);
2155 : }
2156 18864 : else if (varattno == 0)
2157 : {
2158 : /* Whole row reference */
2159 : Relation rel;
2160 : Bitmapset *attrs_used;
2161 :
2162 : /* Required only to be passed down to deparseTargetList(). */
2163 : List *retrieved_attrs;
2164 :
2165 : /*
2166 : * The lock on the relation will be held by upper callers, so it's
2167 : * fine to open it with no lock here.
2168 : */
2169 392 : rel = table_open(rte->relid, NoLock);
2170 :
2171 : /*
2172 : * The local name of the foreign table can not be recognized by the
2173 : * foreign server and the table it references on foreign server might
2174 : * have different column ordering or different columns than those
2175 : * declared locally. Hence we have to deparse whole-row reference as
2176 : * ROW(columns referenced locally). Construct this by deparsing a
2177 : * "whole row" attribute.
2178 : */
2179 392 : attrs_used = bms_add_member(NULL,
2180 : 0 - FirstLowInvalidHeapAttributeNumber);
2181 :
2182 : /*
2183 : * In case the whole-row reference is under an outer join then it has
2184 : * to go NULL whenever the rest of the row goes NULL. Deparsing a join
2185 : * query would always involve multiple relations, thus qualify_col
2186 : * would be true.
2187 : */
2188 392 : if (qualify_col)
2189 : {
2190 384 : appendStringInfoString(buf, "CASE WHEN (");
2191 384 : ADD_REL_QUALIFIER(buf, varno);
2192 384 : appendStringInfoString(buf, "*)::text IS NOT NULL THEN ");
2193 : }
2194 :
2195 392 : appendStringInfoString(buf, "ROW(");
2196 392 : deparseTargetList(buf, rte, varno, rel, false, attrs_used, qualify_col,
2197 : &retrieved_attrs);
2198 392 : appendStringInfoChar(buf, ')');
2199 :
2200 : /* Complete the CASE WHEN statement started above. */
2201 392 : if (qualify_col)
2202 384 : appendStringInfoString(buf, " END");
2203 :
2204 392 : table_close(rel, NoLock);
2205 392 : bms_free(attrs_used);
2206 : }
2207 : else
2208 : {
2209 18472 : char *colname = NULL;
2210 : List *options;
2211 : ListCell *lc;
2212 :
2213 : /* varno must not be any of OUTER_VAR, INNER_VAR and INDEX_VAR. */
2214 : Assert(!IS_SPECIAL_VARNO(varno));
2215 :
2216 : /*
2217 : * If it's a column of a foreign table, and it has the column_name FDW
2218 : * option, use that value.
2219 : */
2220 18472 : options = GetForeignColumnOptions(rte->relid, varattno);
2221 18472 : foreach(lc, options)
2222 : {
2223 4740 : DefElem *def = (DefElem *) lfirst(lc);
2224 :
2225 4740 : if (strcmp(def->defname, "column_name") == 0)
2226 : {
2227 4740 : colname = defGetString(def);
2228 4740 : break;
2229 : }
2230 : }
2231 :
2232 : /*
2233 : * If it's a column of a regular table or it doesn't have column_name
2234 : * FDW option, use attribute name.
2235 : */
2236 18472 : if (colname == NULL)
2237 13732 : colname = get_attname(rte->relid, varattno, false);
2238 :
2239 18472 : if (qualify_col)
2240 8272 : ADD_REL_QUALIFIER(buf, varno);
2241 :
2242 18472 : appendStringInfoString(buf, quote_identifier(colname));
2243 : }
2244 18960 : }
2245 :
2246 : /*
2247 : * Append remote name of specified foreign table to buf.
2248 : * Use value of table_name FDW option (if any) instead of relation's name.
2249 : * Similarly, schema_name FDW option overrides schema name.
2250 : */
2251 : static void
2252 4674 : deparseRelation(StringInfo buf, Relation rel)
2253 : {
2254 : ForeignTable *table;
2255 4674 : const char *nspname = NULL;
2256 4674 : const char *relname = NULL;
2257 : ListCell *lc;
2258 :
2259 : /* obtain additional catalog information. */
2260 4674 : table = GetForeignTable(RelationGetRelid(rel));
2261 :
2262 : /*
2263 : * Use value of FDW options if any, instead of the name of object itself.
2264 : */
2265 15112 : foreach(lc, table->options)
2266 : {
2267 10438 : DefElem *def = (DefElem *) lfirst(lc);
2268 :
2269 10438 : if (strcmp(def->defname, "schema_name") == 0)
2270 3222 : nspname = defGetString(def);
2271 7216 : else if (strcmp(def->defname, "table_name") == 0)
2272 4674 : relname = defGetString(def);
2273 : }
2274 :
2275 : /*
2276 : * Note: we could skip printing the schema name if it's pg_catalog, but
2277 : * that doesn't seem worth the trouble.
2278 : */
2279 4674 : if (nspname == NULL)
2280 1452 : nspname = get_namespace_name(RelationGetNamespace(rel));
2281 4674 : if (relname == NULL)
2282 0 : relname = RelationGetRelationName(rel);
2283 :
2284 4674 : appendStringInfo(buf, "%s.%s",
2285 : quote_identifier(nspname), quote_identifier(relname));
2286 4674 : }
2287 :
2288 : /*
2289 : * Append a SQL string literal representing "val" to buf.
2290 : */
2291 : void
2292 448 : deparseStringLiteral(StringInfo buf, const char *val)
2293 : {
2294 : const char *valptr;
2295 :
2296 : /*
2297 : * Rather than making assumptions about the remote server's value of
2298 : * standard_conforming_strings, always use E'foo' syntax if there are any
2299 : * backslashes. This will fail on remote servers before 8.1, but those
2300 : * are long out of support.
2301 : */
2302 448 : if (strchr(val, '\\') != NULL)
2303 2 : appendStringInfoChar(buf, ESCAPE_STRING_SYNTAX);
2304 448 : appendStringInfoChar(buf, '\'');
2305 3398 : for (valptr = val; *valptr; valptr++)
2306 : {
2307 2950 : char ch = *valptr;
2308 :
2309 2950 : if (SQL_STR_DOUBLE(ch, true))
2310 4 : appendStringInfoChar(buf, ch);
2311 2950 : appendStringInfoChar(buf, ch);
2312 : }
2313 448 : appendStringInfoChar(buf, '\'');
2314 448 : }
2315 :
2316 : /*
2317 : * Deparse given expression into context->buf.
2318 : *
2319 : * This function must support all the same node types that foreign_expr_walker
2320 : * accepts.
2321 : *
2322 : * Note: unlike ruleutils.c, we just use a simple hard-wired parenthesization
2323 : * scheme: anything more complex than a Var, Const, function call or cast
2324 : * should be self-parenthesized.
2325 : */
2326 : static void
2327 16750 : deparseExpr(Expr *node, deparse_expr_cxt *context)
2328 : {
2329 16750 : if (node == NULL)
2330 0 : return;
2331 :
2332 16750 : switch (nodeTag(node))
2333 : {
2334 9732 : case T_Var:
2335 9732 : deparseVar((Var *) node, context);
2336 9732 : break;
2337 2630 : case T_Const:
2338 2630 : deparseConst((Const *) node, context, 0);
2339 2630 : break;
2340 52 : case T_Param:
2341 52 : deparseParam((Param *) node, context);
2342 52 : break;
2343 2 : case T_SubscriptingRef:
2344 2 : deparseSubscriptingRef((SubscriptingRef *) node, context);
2345 2 : break;
2346 96 : case T_FuncExpr:
2347 96 : deparseFuncExpr((FuncExpr *) node, context);
2348 96 : break;
2349 3550 : case T_OpExpr:
2350 3550 : deparseOpExpr((OpExpr *) node, context);
2351 3550 : break;
2352 2 : case T_DistinctExpr:
2353 2 : deparseDistinctExpr((DistinctExpr *) node, context);
2354 2 : break;
2355 8 : case T_ScalarArrayOpExpr:
2356 8 : deparseScalarArrayOpExpr((ScalarArrayOpExpr *) node, context);
2357 8 : break;
2358 64 : case T_RelabelType:
2359 64 : deparseRelabelType((RelabelType *) node, context);
2360 64 : break;
2361 76 : case T_BoolExpr:
2362 76 : deparseBoolExpr((BoolExpr *) node, context);
2363 76 : break;
2364 56 : case T_NullTest:
2365 56 : deparseNullTest((NullTest *) node, context);
2366 56 : break;
2367 8 : case T_ArrayExpr:
2368 8 : deparseArrayExpr((ArrayExpr *) node, context);
2369 8 : break;
2370 474 : case T_Aggref:
2371 474 : deparseAggref((Aggref *) node, context);
2372 474 : break;
2373 0 : default:
2374 0 : elog(ERROR, "unsupported expression type for deparse: %d",
2375 : (int) nodeTag(node));
2376 : break;
2377 : }
2378 : }
2379 :
2380 : /*
2381 : * Deparse given Var node into context->buf.
2382 : *
2383 : * If the Var belongs to the foreign relation, just print its remote name.
2384 : * Otherwise, it's effectively a Param (and will in fact be a Param at
2385 : * run time). Handle it the same way we handle plain Params --- see
2386 : * deparseParam for comments.
2387 : */
2388 : static void
2389 9732 : deparseVar(Var *node, deparse_expr_cxt *context)
2390 : {
2391 9732 : Relids relids = context->scanrel->relids;
2392 : int relno;
2393 : int colno;
2394 :
2395 : /* Qualify columns when multiple relations are involved. */
2396 9732 : bool qualify_col = (bms_membership(relids) == BMS_MULTIPLE);
2397 :
2398 : /*
2399 : * If the Var belongs to the foreign relation that is deparsed as a
2400 : * subquery, use the relation and column alias to the Var provided by the
2401 : * subquery, instead of the remote name.
2402 : */
2403 9732 : if (is_subquery_var(node, context->scanrel, &relno, &colno))
2404 : {
2405 168 : appendStringInfo(context->buf, "%s%d.%s%d",
2406 : SUBQUERY_REL_ALIAS_PREFIX, relno,
2407 : SUBQUERY_COL_ALIAS_PREFIX, colno);
2408 168 : return;
2409 : }
2410 :
2411 9564 : if (bms_is_member(node->varno, relids) && node->varlevelsup == 0)
2412 9284 : deparseColumnRef(context->buf, node->varno, node->varattno,
2413 9284 : planner_rt_fetch(node->varno, context->root),
2414 : qualify_col);
2415 : else
2416 : {
2417 : /* Treat like a Param */
2418 280 : if (context->params_list)
2419 : {
2420 8 : int pindex = 0;
2421 : ListCell *lc;
2422 :
2423 : /* find its index in params_list */
2424 8 : foreach(lc, *context->params_list)
2425 : {
2426 0 : pindex++;
2427 0 : if (equal(node, (Node *) lfirst(lc)))
2428 0 : break;
2429 : }
2430 8 : if (lc == NULL)
2431 : {
2432 : /* not in list, so add it */
2433 8 : pindex++;
2434 8 : *context->params_list = lappend(*context->params_list, node);
2435 : }
2436 :
2437 8 : printRemoteParam(pindex, node->vartype, node->vartypmod, context);
2438 : }
2439 : else
2440 : {
2441 272 : printRemotePlaceholder(node->vartype, node->vartypmod, context);
2442 : }
2443 : }
2444 : }
2445 :
2446 : /*
2447 : * Deparse given constant value into context->buf.
2448 : *
2449 : * This function has to be kept in sync with ruleutils.c's get_const_expr.
2450 : * As for that function, showtype can be -1 to never show "::typename" decoration,
2451 : * or +1 to always show it, or 0 to show it only if the constant wouldn't be assumed
2452 : * to be the right type by default.
2453 : */
2454 : static void
2455 2630 : deparseConst(Const *node, deparse_expr_cxt *context, int showtype)
2456 : {
2457 2630 : StringInfo buf = context->buf;
2458 : Oid typoutput;
2459 : bool typIsVarlena;
2460 : char *extval;
2461 2630 : bool isfloat = false;
2462 : bool needlabel;
2463 :
2464 2630 : if (node->constisnull)
2465 : {
2466 14 : appendStringInfoString(buf, "NULL");
2467 14 : if (showtype >= 0)
2468 14 : appendStringInfo(buf, "::%s",
2469 : deparse_type_name(node->consttype,
2470 : node->consttypmod));
2471 14 : return;
2472 : }
2473 :
2474 2616 : getTypeOutputInfo(node->consttype,
2475 : &typoutput, &typIsVarlena);
2476 2616 : extval = OidOutputFunctionCall(typoutput, node->constvalue);
2477 :
2478 2616 : switch (node->consttype)
2479 : {
2480 2488 : case INT2OID:
2481 : case INT4OID:
2482 : case INT8OID:
2483 : case OIDOID:
2484 : case FLOAT4OID:
2485 : case FLOAT8OID:
2486 : case NUMERICOID:
2487 : {
2488 : /*
2489 : * No need to quote unless it's a special value such as 'NaN'.
2490 : * See comments in get_const_expr().
2491 : */
2492 2488 : if (strspn(extval, "0123456789+-eE.") == strlen(extval))
2493 : {
2494 2488 : if (extval[0] == '+' || extval[0] == '-')
2495 2 : appendStringInfo(buf, "(%s)", extval);
2496 : else
2497 2486 : appendStringInfoString(buf, extval);
2498 2488 : if (strcspn(extval, "eE.") != strlen(extval))
2499 4 : isfloat = true; /* it looks like a float */
2500 : }
2501 : else
2502 0 : appendStringInfo(buf, "'%s'", extval);
2503 : }
2504 2488 : break;
2505 0 : case BITOID:
2506 : case VARBITOID:
2507 0 : appendStringInfo(buf, "B'%s'", extval);
2508 0 : break;
2509 0 : case BOOLOID:
2510 0 : if (strcmp(extval, "t") == 0)
2511 0 : appendStringInfoString(buf, "true");
2512 : else
2513 0 : appendStringInfoString(buf, "false");
2514 0 : break;
2515 128 : default:
2516 128 : deparseStringLiteral(buf, extval);
2517 128 : break;
2518 : }
2519 :
2520 2616 : pfree(extval);
2521 :
2522 2616 : if (showtype < 0)
2523 0 : return;
2524 :
2525 : /*
2526 : * For showtype == 0, append ::typename unless the constant will be
2527 : * implicitly typed as the right type when it is read in.
2528 : *
2529 : * XXX this code has to be kept in sync with the behavior of the parser,
2530 : * especially make_const.
2531 : */
2532 2616 : switch (node->consttype)
2533 : {
2534 2104 : case BOOLOID:
2535 : case INT4OID:
2536 : case UNKNOWNOID:
2537 2104 : needlabel = false;
2538 2104 : break;
2539 44 : case NUMERICOID:
2540 44 : needlabel = !isfloat || (node->consttypmod >= 0);
2541 44 : break;
2542 468 : default:
2543 468 : needlabel = true;
2544 468 : break;
2545 : }
2546 2616 : if (needlabel || showtype > 0)
2547 508 : appendStringInfo(buf, "::%s",
2548 : deparse_type_name(node->consttype,
2549 : node->consttypmod));
2550 : }
2551 :
2552 : /*
2553 : * Deparse given Param node.
2554 : *
2555 : * If we're generating the query "for real", add the Param to
2556 : * context->params_list if it's not already present, and then use its index
2557 : * in that list as the remote parameter number. During EXPLAIN, there's
2558 : * no need to identify a parameter number.
2559 : */
2560 : static void
2561 52 : deparseParam(Param *node, deparse_expr_cxt *context)
2562 : {
2563 52 : if (context->params_list)
2564 : {
2565 32 : int pindex = 0;
2566 : ListCell *lc;
2567 :
2568 : /* find its index in params_list */
2569 36 : foreach(lc, *context->params_list)
2570 : {
2571 4 : pindex++;
2572 4 : if (equal(node, (Node *) lfirst(lc)))
2573 0 : break;
2574 : }
2575 32 : if (lc == NULL)
2576 : {
2577 : /* not in list, so add it */
2578 32 : pindex++;
2579 32 : *context->params_list = lappend(*context->params_list, node);
2580 : }
2581 :
2582 32 : printRemoteParam(pindex, node->paramtype, node->paramtypmod, context);
2583 : }
2584 : else
2585 : {
2586 20 : printRemotePlaceholder(node->paramtype, node->paramtypmod, context);
2587 : }
2588 52 : }
2589 :
2590 : /*
2591 : * Deparse a container subscript expression.
2592 : */
2593 : static void
2594 2 : deparseSubscriptingRef(SubscriptingRef *node, deparse_expr_cxt *context)
2595 : {
2596 2 : StringInfo buf = context->buf;
2597 : ListCell *lowlist_item;
2598 : ListCell *uplist_item;
2599 :
2600 : /* Always parenthesize the expression. */
2601 2 : appendStringInfoChar(buf, '(');
2602 :
2603 : /*
2604 : * Deparse referenced array expression first. If that expression includes
2605 : * a cast, we have to parenthesize to prevent the array subscript from
2606 : * being taken as typename decoration. We can avoid that in the typical
2607 : * case of subscripting a Var, but otherwise do it.
2608 : */
2609 2 : if (IsA(node->refexpr, Var))
2610 0 : deparseExpr(node->refexpr, context);
2611 : else
2612 : {
2613 2 : appendStringInfoChar(buf, '(');
2614 2 : deparseExpr(node->refexpr, context);
2615 2 : appendStringInfoChar(buf, ')');
2616 : }
2617 :
2618 : /* Deparse subscript expressions. */
2619 2 : lowlist_item = list_head(node->reflowerindexpr); /* could be NULL */
2620 4 : foreach(uplist_item, node->refupperindexpr)
2621 : {
2622 2 : appendStringInfoChar(buf, '[');
2623 2 : if (lowlist_item)
2624 : {
2625 0 : deparseExpr(lfirst(lowlist_item), context);
2626 0 : appendStringInfoChar(buf, ':');
2627 0 : lowlist_item = lnext(node->reflowerindexpr, lowlist_item);
2628 : }
2629 2 : deparseExpr(lfirst(uplist_item), context);
2630 2 : appendStringInfoChar(buf, ']');
2631 : }
2632 :
2633 2 : appendStringInfoChar(buf, ')');
2634 2 : }
2635 :
2636 : /*
2637 : * Deparse a function call.
2638 : */
2639 : static void
2640 96 : deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context)
2641 : {
2642 96 : StringInfo buf = context->buf;
2643 : bool use_variadic;
2644 : bool first;
2645 : ListCell *arg;
2646 :
2647 : /*
2648 : * If the function call came from an implicit coercion, then just show the
2649 : * first argument.
2650 : */
2651 96 : if (node->funcformat == COERCE_IMPLICIT_CAST)
2652 : {
2653 44 : deparseExpr((Expr *) linitial(node->args), context);
2654 44 : return;
2655 : }
2656 :
2657 : /*
2658 : * If the function call came from a cast, then show the first argument
2659 : * plus an explicit cast operation.
2660 : */
2661 52 : if (node->funcformat == COERCE_EXPLICIT_CAST)
2662 : {
2663 0 : Oid rettype = node->funcresulttype;
2664 : int32 coercedTypmod;
2665 :
2666 : /* Get the typmod if this is a length-coercion function */
2667 0 : (void) exprIsLengthCoercion((Node *) node, &coercedTypmod);
2668 :
2669 0 : deparseExpr((Expr *) linitial(node->args), context);
2670 0 : appendStringInfo(buf, "::%s",
2671 : deparse_type_name(rettype, coercedTypmod));
2672 0 : return;
2673 : }
2674 :
2675 : /* Check if need to print VARIADIC (cf. ruleutils.c) */
2676 52 : use_variadic = node->funcvariadic;
2677 :
2678 : /*
2679 : * Normal function: display as proname(args).
2680 : */
2681 52 : appendFunctionName(node->funcid, context);
2682 52 : appendStringInfoChar(buf, '(');
2683 :
2684 : /* ... and all the arguments */
2685 52 : first = true;
2686 106 : foreach(arg, node->args)
2687 : {
2688 54 : if (!first)
2689 2 : appendStringInfoString(buf, ", ");
2690 54 : if (use_variadic && lnext(node->args, arg) == NULL)
2691 0 : appendStringInfoString(buf, "VARIADIC ");
2692 54 : deparseExpr((Expr *) lfirst(arg), context);
2693 54 : first = false;
2694 : }
2695 52 : appendStringInfoChar(buf, ')');
2696 : }
2697 :
2698 : /*
2699 : * Deparse given operator expression. To avoid problems around
2700 : * priority of operations, we always parenthesize the arguments.
2701 : */
2702 : static void
2703 3550 : deparseOpExpr(OpExpr *node, deparse_expr_cxt *context)
2704 : {
2705 3550 : StringInfo buf = context->buf;
2706 : HeapTuple tuple;
2707 : Form_pg_operator form;
2708 : char oprkind;
2709 : ListCell *arg;
2710 :
2711 : /* Retrieve information about the operator from system catalog. */
2712 3550 : tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(node->opno));
2713 3550 : if (!HeapTupleIsValid(tuple))
2714 0 : elog(ERROR, "cache lookup failed for operator %u", node->opno);
2715 3550 : form = (Form_pg_operator) GETSTRUCT(tuple);
2716 3550 : oprkind = form->oprkind;
2717 :
2718 : /* Sanity check. */
2719 : Assert((oprkind == 'r' && list_length(node->args) == 1) ||
2720 : (oprkind == 'l' && list_length(node->args) == 1) ||
2721 : (oprkind == 'b' && list_length(node->args) == 2));
2722 :
2723 : /* Always parenthesize the expression. */
2724 3550 : appendStringInfoChar(buf, '(');
2725 :
2726 : /* Deparse left operand. */
2727 3550 : if (oprkind == 'r' || oprkind == 'b')
2728 : {
2729 3544 : arg = list_head(node->args);
2730 3544 : deparseExpr(lfirst(arg), context);
2731 3544 : appendStringInfoChar(buf, ' ');
2732 : }
2733 :
2734 : /* Deparse operator name. */
2735 3550 : deparseOperatorName(buf, form);
2736 :
2737 : /* Deparse right operand. */
2738 3550 : if (oprkind == 'l' || oprkind == 'b')
2739 : {
2740 3548 : arg = list_tail(node->args);
2741 3548 : appendStringInfoChar(buf, ' ');
2742 3548 : deparseExpr(lfirst(arg), context);
2743 : }
2744 :
2745 3550 : appendStringInfoChar(buf, ')');
2746 :
2747 3550 : ReleaseSysCache(tuple);
2748 3550 : }
2749 :
2750 : /*
2751 : * Print the name of an operator.
2752 : */
2753 : static void
2754 3566 : deparseOperatorName(StringInfo buf, Form_pg_operator opform)
2755 : {
2756 : char *opname;
2757 :
2758 : /* opname is not a SQL identifier, so we should not quote it. */
2759 3566 : opname = NameStr(opform->oprname);
2760 :
2761 : /* Print schema name only if it's not pg_catalog */
2762 3566 : if (opform->oprnamespace != PG_CATALOG_NAMESPACE)
2763 : {
2764 : const char *opnspname;
2765 :
2766 18 : opnspname = get_namespace_name(opform->oprnamespace);
2767 : /* Print fully qualified operator name. */
2768 18 : appendStringInfo(buf, "OPERATOR(%s.%s)",
2769 : quote_identifier(opnspname), opname);
2770 : }
2771 : else
2772 : {
2773 : /* Just print operator name. */
2774 3548 : appendStringInfoString(buf, opname);
2775 : }
2776 3566 : }
2777 :
2778 : /*
2779 : * Deparse IS DISTINCT FROM.
2780 : */
2781 : static void
2782 2 : deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context)
2783 : {
2784 2 : StringInfo buf = context->buf;
2785 :
2786 : Assert(list_length(node->args) == 2);
2787 :
2788 2 : appendStringInfoChar(buf, '(');
2789 2 : deparseExpr(linitial(node->args), context);
2790 2 : appendStringInfoString(buf, " IS DISTINCT FROM ");
2791 2 : deparseExpr(lsecond(node->args), context);
2792 2 : appendStringInfoChar(buf, ')');
2793 2 : }
2794 :
2795 : /*
2796 : * Deparse given ScalarArrayOpExpr expression. To avoid problems
2797 : * around priority of operations, we always parenthesize the arguments.
2798 : */
2799 : static void
2800 8 : deparseScalarArrayOpExpr(ScalarArrayOpExpr *node, deparse_expr_cxt *context)
2801 : {
2802 8 : StringInfo buf = context->buf;
2803 : HeapTuple tuple;
2804 : Form_pg_operator form;
2805 : Expr *arg1;
2806 : Expr *arg2;
2807 :
2808 : /* Retrieve information about the operator from system catalog. */
2809 8 : tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(node->opno));
2810 8 : if (!HeapTupleIsValid(tuple))
2811 0 : elog(ERROR, "cache lookup failed for operator %u", node->opno);
2812 8 : form = (Form_pg_operator) GETSTRUCT(tuple);
2813 :
2814 : /* Sanity check. */
2815 : Assert(list_length(node->args) == 2);
2816 :
2817 : /* Always parenthesize the expression. */
2818 8 : appendStringInfoChar(buf, '(');
2819 :
2820 : /* Deparse left operand. */
2821 8 : arg1 = linitial(node->args);
2822 8 : deparseExpr(arg1, context);
2823 8 : appendStringInfoChar(buf, ' ');
2824 :
2825 : /* Deparse operator name plus decoration. */
2826 8 : deparseOperatorName(buf, form);
2827 8 : appendStringInfo(buf, " %s (", node->useOr ? "ANY" : "ALL");
2828 :
2829 : /* Deparse right operand. */
2830 8 : arg2 = lsecond(node->args);
2831 8 : deparseExpr(arg2, context);
2832 :
2833 8 : appendStringInfoChar(buf, ')');
2834 :
2835 : /* Always parenthesize the expression. */
2836 8 : appendStringInfoChar(buf, ')');
2837 :
2838 8 : ReleaseSysCache(tuple);
2839 8 : }
2840 :
2841 : /*
2842 : * Deparse a RelabelType (binary-compatible cast) node.
2843 : */
2844 : static void
2845 64 : deparseRelabelType(RelabelType *node, deparse_expr_cxt *context)
2846 : {
2847 64 : deparseExpr(node->arg, context);
2848 64 : if (node->relabelformat != COERCE_IMPLICIT_CAST)
2849 0 : appendStringInfo(context->buf, "::%s",
2850 : deparse_type_name(node->resulttype,
2851 : node->resulttypmod));
2852 64 : }
2853 :
2854 : /*
2855 : * Deparse a BoolExpr node.
2856 : */
2857 : static void
2858 76 : deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context)
2859 : {
2860 76 : StringInfo buf = context->buf;
2861 76 : const char *op = NULL; /* keep compiler quiet */
2862 : bool first;
2863 : ListCell *lc;
2864 :
2865 76 : switch (node->boolop)
2866 : {
2867 36 : case AND_EXPR:
2868 36 : op = "AND";
2869 36 : break;
2870 40 : case OR_EXPR:
2871 40 : op = "OR";
2872 40 : break;
2873 0 : case NOT_EXPR:
2874 0 : appendStringInfoString(buf, "(NOT ");
2875 0 : deparseExpr(linitial(node->args), context);
2876 0 : appendStringInfoChar(buf, ')');
2877 0 : return;
2878 : }
2879 :
2880 76 : appendStringInfoChar(buf, '(');
2881 76 : first = true;
2882 228 : foreach(lc, node->args)
2883 : {
2884 152 : if (!first)
2885 76 : appendStringInfo(buf, " %s ", op);
2886 152 : deparseExpr((Expr *) lfirst(lc), context);
2887 152 : first = false;
2888 : }
2889 76 : appendStringInfoChar(buf, ')');
2890 : }
2891 :
2892 : /*
2893 : * Deparse IS [NOT] NULL expression.
2894 : */
2895 : static void
2896 56 : deparseNullTest(NullTest *node, deparse_expr_cxt *context)
2897 : {
2898 56 : StringInfo buf = context->buf;
2899 :
2900 56 : appendStringInfoChar(buf, '(');
2901 56 : deparseExpr(node->arg, context);
2902 :
2903 : /*
2904 : * For scalar inputs, we prefer to print as IS [NOT] NULL, which is
2905 : * shorter and traditional. If it's a rowtype input but we're applying a
2906 : * scalar test, must print IS [NOT] DISTINCT FROM NULL to be semantically
2907 : * correct.
2908 : */
2909 56 : if (node->argisrow || !type_is_rowtype(exprType((Node *) node->arg)))
2910 : {
2911 112 : if (node->nulltesttype == IS_NULL)
2912 38 : appendStringInfoString(buf, " IS NULL)");
2913 : else
2914 18 : appendStringInfoString(buf, " IS NOT NULL)");
2915 : }
2916 : else
2917 : {
2918 0 : if (node->nulltesttype == IS_NULL)
2919 0 : appendStringInfoString(buf, " IS NOT DISTINCT FROM NULL)");
2920 : else
2921 0 : appendStringInfoString(buf, " IS DISTINCT FROM NULL)");
2922 : }
2923 56 : }
2924 :
2925 : /*
2926 : * Deparse ARRAY[...] construct.
2927 : */
2928 : static void
2929 8 : deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context)
2930 : {
2931 8 : StringInfo buf = context->buf;
2932 8 : bool first = true;
2933 : ListCell *lc;
2934 :
2935 8 : appendStringInfoString(buf, "ARRAY[");
2936 24 : foreach(lc, node->elements)
2937 : {
2938 16 : if (!first)
2939 8 : appendStringInfoString(buf, ", ");
2940 16 : deparseExpr(lfirst(lc), context);
2941 16 : first = false;
2942 : }
2943 8 : appendStringInfoChar(buf, ']');
2944 :
2945 : /* If the array is empty, we need an explicit cast to the array type. */
2946 8 : if (node->elements == NIL)
2947 0 : appendStringInfo(buf, "::%s",
2948 : deparse_type_name(node->array_typeid, -1));
2949 8 : }
2950 :
2951 : /*
2952 : * Deparse an Aggref node.
2953 : */
2954 : static void
2955 474 : deparseAggref(Aggref *node, deparse_expr_cxt *context)
2956 : {
2957 474 : StringInfo buf = context->buf;
2958 : bool use_variadic;
2959 :
2960 : /* Only basic, non-split aggregation accepted. */
2961 : Assert(node->aggsplit == AGGSPLIT_SIMPLE);
2962 :
2963 : /* Check if need to print VARIADIC (cf. ruleutils.c) */
2964 474 : use_variadic = node->aggvariadic;
2965 :
2966 : /* Find aggregate name from aggfnoid which is a pg_proc entry */
2967 474 : appendFunctionName(node->aggfnoid, context);
2968 474 : appendStringInfoChar(buf, '(');
2969 :
2970 : /* Add DISTINCT */
2971 474 : appendStringInfoString(buf, (node->aggdistinct != NIL) ? "DISTINCT " : "");
2972 :
2973 474 : if (AGGKIND_IS_ORDERED_SET(node->aggkind))
2974 : {
2975 : /* Add WITHIN GROUP (ORDER BY ..) */
2976 : ListCell *arg;
2977 16 : bool first = true;
2978 :
2979 : Assert(!node->aggvariadic);
2980 : Assert(node->aggorder != NIL);
2981 :
2982 36 : foreach(arg, node->aggdirectargs)
2983 : {
2984 20 : if (!first)
2985 4 : appendStringInfoString(buf, ", ");
2986 20 : first = false;
2987 :
2988 20 : deparseExpr((Expr *) lfirst(arg), context);
2989 : }
2990 :
2991 16 : appendStringInfoString(buf, ") WITHIN GROUP (ORDER BY ");
2992 16 : appendAggOrderBy(node->aggorder, node->args, context);
2993 : }
2994 : else
2995 : {
2996 : /* aggstar can be set only in zero-argument aggregates */
2997 458 : if (node->aggstar)
2998 100 : appendStringInfoChar(buf, '*');
2999 : else
3000 : {
3001 : ListCell *arg;
3002 358 : bool first = true;
3003 :
3004 : /* Add all the arguments */
3005 724 : foreach(arg, node->args)
3006 : {
3007 366 : TargetEntry *tle = (TargetEntry *) lfirst(arg);
3008 366 : Node *n = (Node *) tle->expr;
3009 :
3010 366 : if (tle->resjunk)
3011 8 : continue;
3012 :
3013 358 : if (!first)
3014 0 : appendStringInfoString(buf, ", ");
3015 358 : first = false;
3016 :
3017 : /* Add VARIADIC */
3018 358 : if (use_variadic && lnext(node->args, arg) == NULL)
3019 4 : appendStringInfoString(buf, "VARIADIC ");
3020 :
3021 358 : deparseExpr((Expr *) n, context);
3022 : }
3023 : }
3024 :
3025 : /* Add ORDER BY */
3026 458 : if (node->aggorder != NIL)
3027 : {
3028 44 : appendStringInfoString(buf, " ORDER BY ");
3029 44 : appendAggOrderBy(node->aggorder, node->args, context);
3030 : }
3031 : }
3032 :
3033 : /* Add FILTER (WHERE ..) */
3034 474 : if (node->aggfilter != NULL)
3035 : {
3036 24 : appendStringInfoString(buf, ") FILTER (WHERE ");
3037 24 : deparseExpr((Expr *) node->aggfilter, context);
3038 : }
3039 :
3040 474 : appendStringInfoChar(buf, ')');
3041 474 : }
3042 :
3043 : /*
3044 : * Append ORDER BY within aggregate function.
3045 : */
3046 : static void
3047 60 : appendAggOrderBy(List *orderList, List *targetList, deparse_expr_cxt *context)
3048 : {
3049 60 : StringInfo buf = context->buf;
3050 : ListCell *lc;
3051 60 : bool first = true;
3052 :
3053 124 : foreach(lc, orderList)
3054 : {
3055 64 : SortGroupClause *srt = (SortGroupClause *) lfirst(lc);
3056 : Node *sortexpr;
3057 : Oid sortcoltype;
3058 : TypeCacheEntry *typentry;
3059 :
3060 64 : if (!first)
3061 4 : appendStringInfoString(buf, ", ");
3062 64 : first = false;
3063 :
3064 64 : sortexpr = deparseSortGroupClause(srt->tleSortGroupRef, targetList,
3065 : false, context);
3066 64 : sortcoltype = exprType(sortexpr);
3067 : /* See whether operator is default < or > for datatype */
3068 64 : typentry = lookup_type_cache(sortcoltype,
3069 : TYPECACHE_LT_OPR | TYPECACHE_GT_OPR);
3070 64 : if (srt->sortop == typentry->lt_opr)
3071 40 : appendStringInfoString(buf, " ASC");
3072 24 : else if (srt->sortop == typentry->gt_opr)
3073 16 : appendStringInfoString(buf, " DESC");
3074 : else
3075 : {
3076 : HeapTuple opertup;
3077 : Form_pg_operator operform;
3078 :
3079 8 : appendStringInfoString(buf, " USING ");
3080 :
3081 : /* Append operator name. */
3082 8 : opertup = SearchSysCache1(OPEROID, ObjectIdGetDatum(srt->sortop));
3083 8 : if (!HeapTupleIsValid(opertup))
3084 0 : elog(ERROR, "cache lookup failed for operator %u", srt->sortop);
3085 8 : operform = (Form_pg_operator) GETSTRUCT(opertup);
3086 8 : deparseOperatorName(buf, operform);
3087 8 : ReleaseSysCache(opertup);
3088 : }
3089 :
3090 64 : if (srt->nulls_first)
3091 8 : appendStringInfoString(buf, " NULLS FIRST");
3092 : else
3093 56 : appendStringInfoString(buf, " NULLS LAST");
3094 : }
3095 60 : }
3096 :
3097 : /*
3098 : * Print the representation of a parameter to be sent to the remote side.
3099 : *
3100 : * Note: we always label the Param's type explicitly rather than relying on
3101 : * transmitting a numeric type OID in PQexecParams(). This allows us to
3102 : * avoid assuming that types have the same OIDs on the remote side as they
3103 : * do locally --- they need only have the same names.
3104 : */
3105 : static void
3106 40 : printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod,
3107 : deparse_expr_cxt *context)
3108 : {
3109 40 : StringInfo buf = context->buf;
3110 40 : char *ptypename = deparse_type_name(paramtype, paramtypmod);
3111 :
3112 40 : appendStringInfo(buf, "$%d::%s", paramindex, ptypename);
3113 40 : }
3114 :
3115 : /*
3116 : * Print the representation of a placeholder for a parameter that will be
3117 : * sent to the remote side at execution time.
3118 : *
3119 : * This is used when we're just trying to EXPLAIN the remote query.
3120 : * We don't have the actual value of the runtime parameter yet, and we don't
3121 : * want the remote planner to generate a plan that depends on such a value
3122 : * anyway. Thus, we can't do something simple like "$1::paramtype".
3123 : * Instead, we emit "((SELECT null::paramtype)::paramtype)".
3124 : * In all extant versions of Postgres, the planner will see that as an unknown
3125 : * constant value, which is what we want. This might need adjustment if we
3126 : * ever make the planner flatten scalar subqueries. Note: the reason for the
3127 : * apparently useless outer cast is to ensure that the representation as a
3128 : * whole will be parsed as an a_expr and not a select_with_parens; the latter
3129 : * would do the wrong thing in the context "x = ANY(...)".
3130 : */
3131 : static void
3132 292 : printRemotePlaceholder(Oid paramtype, int32 paramtypmod,
3133 : deparse_expr_cxt *context)
3134 : {
3135 292 : StringInfo buf = context->buf;
3136 292 : char *ptypename = deparse_type_name(paramtype, paramtypmod);
3137 :
3138 292 : appendStringInfo(buf, "((SELECT null::%s)::%s)", ptypename, ptypename);
3139 292 : }
3140 :
3141 : /*
3142 : * Deparse GROUP BY clause.
3143 : */
3144 : static void
3145 280 : appendGroupByClause(List *tlist, deparse_expr_cxt *context)
3146 : {
3147 280 : StringInfo buf = context->buf;
3148 280 : Query *query = context->root->parse;
3149 : ListCell *lc;
3150 280 : bool first = true;
3151 :
3152 : /* Nothing to be done, if there's no GROUP BY clause in the query. */
3153 280 : if (!query->groupClause)
3154 78 : return;
3155 :
3156 202 : appendStringInfoString(buf, " GROUP BY ");
3157 :
3158 : /*
3159 : * Queries with grouping sets are not pushed down, so we don't expect
3160 : * grouping sets here.
3161 : */
3162 : Assert(!query->groupingSets);
3163 :
3164 428 : foreach(lc, query->groupClause)
3165 : {
3166 226 : SortGroupClause *grp = (SortGroupClause *) lfirst(lc);
3167 :
3168 226 : if (!first)
3169 24 : appendStringInfoString(buf, ", ");
3170 226 : first = false;
3171 :
3172 226 : deparseSortGroupClause(grp->tleSortGroupRef, tlist, true, context);
3173 : }
3174 : }
3175 :
3176 : /*
3177 : * Deparse ORDER BY clause according to the given pathkeys for given base
3178 : * relation. From given pathkeys expressions belonging entirely to the given
3179 : * base relation are obtained and deparsed.
3180 : */
3181 : static void
3182 922 : appendOrderByClause(List *pathkeys, bool has_final_sort,
3183 : deparse_expr_cxt *context)
3184 : {
3185 : ListCell *lcell;
3186 : int nestlevel;
3187 922 : char *delim = " ";
3188 922 : RelOptInfo *baserel = context->scanrel;
3189 922 : StringInfo buf = context->buf;
3190 :
3191 : /* Make sure any constants in the exprs are printed portably */
3192 922 : nestlevel = set_transmission_modes();
3193 :
3194 922 : appendStringInfoString(buf, " ORDER BY");
3195 2100 : foreach(lcell, pathkeys)
3196 : {
3197 1178 : PathKey *pathkey = lfirst(lcell);
3198 : Expr *em_expr;
3199 :
3200 1178 : if (has_final_sort)
3201 : {
3202 : /*
3203 : * By construction, context->foreignrel is the input relation to
3204 : * the final sort.
3205 : */
3206 338 : em_expr = find_em_expr_for_input_target(context->root,
3207 : pathkey->pk_eclass,
3208 338 : context->foreignrel->reltarget);
3209 : }
3210 : else
3211 840 : em_expr = find_em_expr_for_rel(pathkey->pk_eclass, baserel);
3212 :
3213 : Assert(em_expr != NULL);
3214 :
3215 1178 : appendStringInfoString(buf, delim);
3216 1178 : deparseExpr(em_expr, context);
3217 1178 : if (pathkey->pk_strategy == BTLessStrategyNumber)
3218 1168 : appendStringInfoString(buf, " ASC");
3219 : else
3220 10 : appendStringInfoString(buf, " DESC");
3221 :
3222 1178 : if (pathkey->pk_nulls_first)
3223 10 : appendStringInfoString(buf, " NULLS FIRST");
3224 : else
3225 1168 : appendStringInfoString(buf, " NULLS LAST");
3226 :
3227 1178 : delim = ", ";
3228 : }
3229 922 : reset_transmission_modes(nestlevel);
3230 922 : }
3231 :
3232 : /*
3233 : * Deparse LIMIT/OFFSET clause.
3234 : */
3235 : static void
3236 194 : appendLimitClause(deparse_expr_cxt *context)
3237 : {
3238 194 : PlannerInfo *root = context->root;
3239 194 : StringInfo buf = context->buf;
3240 : int nestlevel;
3241 :
3242 : /* Make sure any constants in the exprs are printed portably */
3243 194 : nestlevel = set_transmission_modes();
3244 :
3245 194 : if (root->parse->limitCount)
3246 : {
3247 194 : appendStringInfoString(buf, " LIMIT ");
3248 194 : deparseExpr((Expr *) root->parse->limitCount, context);
3249 : }
3250 194 : if (root->parse->limitOffset)
3251 : {
3252 142 : appendStringInfoString(buf, " OFFSET ");
3253 142 : deparseExpr((Expr *) root->parse->limitOffset, context);
3254 : }
3255 :
3256 194 : reset_transmission_modes(nestlevel);
3257 194 : }
3258 :
3259 : /*
3260 : * appendFunctionName
3261 : * Deparses function name from given function oid.
3262 : */
3263 : static void
3264 526 : appendFunctionName(Oid funcid, deparse_expr_cxt *context)
3265 : {
3266 526 : StringInfo buf = context->buf;
3267 : HeapTuple proctup;
3268 : Form_pg_proc procform;
3269 : const char *proname;
3270 :
3271 526 : proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
3272 526 : if (!HeapTupleIsValid(proctup))
3273 0 : elog(ERROR, "cache lookup failed for function %u", funcid);
3274 526 : procform = (Form_pg_proc) GETSTRUCT(proctup);
3275 :
3276 : /* Print schema name only if it's not pg_catalog */
3277 526 : if (procform->pronamespace != PG_CATALOG_NAMESPACE)
3278 : {
3279 : const char *schemaname;
3280 :
3281 12 : schemaname = get_namespace_name(procform->pronamespace);
3282 12 : appendStringInfo(buf, "%s.", quote_identifier(schemaname));
3283 : }
3284 :
3285 : /* Always print the function name */
3286 526 : proname = NameStr(procform->proname);
3287 526 : appendStringInfoString(buf, quote_identifier(proname));
3288 :
3289 526 : ReleaseSysCache(proctup);
3290 526 : }
3291 :
3292 : /*
3293 : * Appends a sort or group clause.
3294 : *
3295 : * Like get_rule_sortgroupclause(), returns the expression tree, so caller
3296 : * need not find it again.
3297 : */
3298 : static Node *
3299 290 : deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
3300 : deparse_expr_cxt *context)
3301 : {
3302 290 : StringInfo buf = context->buf;
3303 : TargetEntry *tle;
3304 : Expr *expr;
3305 :
3306 290 : tle = get_sortgroupref_tle(ref, tlist);
3307 290 : expr = tle->expr;
3308 :
3309 290 : if (force_colno)
3310 : {
3311 : /* Use column-number form when requested by caller. */
3312 : Assert(!tle->resjunk);
3313 226 : appendStringInfo(buf, "%d", tle->resno);
3314 : }
3315 64 : else if (expr && IsA(expr, Const))
3316 : {
3317 : /*
3318 : * Force a typecast here so that we don't emit something like "GROUP
3319 : * BY 2", which will be misconstrued as a column position rather than
3320 : * a constant.
3321 : */
3322 0 : deparseConst((Const *) expr, context, 1);
3323 : }
3324 64 : else if (!expr || IsA(expr, Var))
3325 36 : deparseExpr(expr, context);
3326 : else
3327 : {
3328 : /* Always parenthesize the expression. */
3329 28 : appendStringInfoChar(buf, '(');
3330 28 : deparseExpr(expr, context);
3331 28 : appendStringInfoChar(buf, ')');
3332 : }
3333 :
3334 290 : return (Node *) expr;
3335 : }
3336 :
3337 :
3338 : /*
3339 : * Returns true if given Var is deparsed as a subquery output column, in
3340 : * which case, *relno and *colno are set to the IDs for the relation and
3341 : * column alias to the Var provided by the subquery.
3342 : */
3343 : static bool
3344 9732 : is_subquery_var(Var *node, RelOptInfo *foreignrel, int *relno, int *colno)
3345 : {
3346 9732 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
3347 9732 : RelOptInfo *outerrel = fpinfo->outerrel;
3348 9732 : RelOptInfo *innerrel = fpinfo->innerrel;
3349 :
3350 : /* Should only be called in these cases. */
3351 : Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
3352 :
3353 : /*
3354 : * If the given relation isn't a join relation, it doesn't have any lower
3355 : * subqueries, so the Var isn't a subquery output column.
3356 : */
3357 9732 : if (!IS_JOIN_REL(foreignrel))
3358 3140 : return false;
3359 :
3360 : /*
3361 : * If the Var doesn't belong to any lower subqueries, it isn't a subquery
3362 : * output column.
3363 : */
3364 6592 : if (!bms_is_member(node->varno, fpinfo->lower_subquery_rels))
3365 6424 : return false;
3366 :
3367 168 : if (bms_is_member(node->varno, outerrel->relids))
3368 : {
3369 : /*
3370 : * If outer relation is deparsed as a subquery, the Var is an output
3371 : * column of the subquery; get the IDs for the relation/column alias.
3372 : */
3373 84 : if (fpinfo->make_outerrel_subquery)
3374 : {
3375 84 : get_relation_column_alias_ids(node, outerrel, relno, colno);
3376 84 : return true;
3377 : }
3378 :
3379 : /* Otherwise, recurse into the outer relation. */
3380 0 : return is_subquery_var(node, outerrel, relno, colno);
3381 : }
3382 : else
3383 : {
3384 : Assert(bms_is_member(node->varno, innerrel->relids));
3385 :
3386 : /*
3387 : * If inner relation is deparsed as a subquery, the Var is an output
3388 : * column of the subquery; get the IDs for the relation/column alias.
3389 : */
3390 84 : if (fpinfo->make_innerrel_subquery)
3391 : {
3392 84 : get_relation_column_alias_ids(node, innerrel, relno, colno);
3393 84 : return true;
3394 : }
3395 :
3396 : /* Otherwise, recurse into the inner relation. */
3397 0 : return is_subquery_var(node, innerrel, relno, colno);
3398 : }
3399 : }
3400 :
3401 : /*
3402 : * Get the IDs for the relation and column alias to given Var belonging to
3403 : * given relation, which are returned into *relno and *colno.
3404 : */
3405 : static void
3406 168 : get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel,
3407 : int *relno, int *colno)
3408 : {
3409 168 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
3410 : int i;
3411 : ListCell *lc;
3412 :
3413 : /* Get the relation alias ID */
3414 168 : *relno = fpinfo->relation_index;
3415 :
3416 : /* Get the column alias ID */
3417 168 : i = 1;
3418 192 : foreach(lc, foreignrel->reltarget->exprs)
3419 : {
3420 192 : if (equal(lfirst(lc), (Node *) node))
3421 : {
3422 168 : *colno = i;
3423 168 : return;
3424 : }
3425 24 : i++;
3426 : }
3427 :
3428 : /* Shouldn't get here */
3429 0 : elog(ERROR, "unexpected expression in subquery output");
3430 : }
|
