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) 2012-2018, PostgreSQL Global Development Group
28 : *
29 : * IDENTIFICATION
30 : * contrib/postgres_fdw/deparse.c
31 : *
32 : *-------------------------------------------------------------------------
33 : */
34 : #include "postgres.h"
35 :
36 : #include "postgres_fdw.h"
37 :
38 : #include "access/heapam.h"
39 : #include "access/htup_details.h"
40 : #include "access/sysattr.h"
41 : #include "catalog/pg_aggregate.h"
42 : #include "catalog/pg_collation.h"
43 : #include "catalog/pg_namespace.h"
44 : #include "catalog/pg_operator.h"
45 : #include "catalog/pg_proc.h"
46 : #include "catalog/pg_type.h"
47 : #include "commands/defrem.h"
48 : #include "nodes/makefuncs.h"
49 : #include "nodes/nodeFuncs.h"
50 : #include "nodes/plannodes.h"
51 : #include "optimizer/clauses.h"
52 : #include "optimizer/prep.h"
53 : #include "optimizer/tlist.h"
54 : #include "optimizer/var.h"
55 : #include "parser/parsetree.h"
56 : #include "utils/builtins.h"
57 : #include "utils/lsyscache.h"
58 : #include "utils/rel.h"
59 : #include "utils/syscache.h"
60 : #include "utils/typcache.h"
61 :
62 :
63 : /*
64 : * Global context for foreign_expr_walker's search of an expression tree.
65 : */
66 : typedef struct foreign_glob_cxt
67 : {
68 : PlannerInfo *root; /* global planner state */
69 : RelOptInfo *foreignrel; /* the foreign relation we are planning for */
70 : Relids relids; /* relids of base relations in the underlying
71 : * scan */
72 : } foreign_glob_cxt;
73 :
74 : /*
75 : * Local (per-tree-level) context for foreign_expr_walker's search.
76 : * This is concerned with identifying collations used in the expression.
77 : */
78 : typedef enum
79 : {
80 : FDW_COLLATE_NONE, /* expression is of a noncollatable type, or
81 : * it has default collation that is not
82 : * traceable to a foreign Var */
83 : FDW_COLLATE_SAFE, /* collation derives from a foreign Var */
84 : FDW_COLLATE_UNSAFE /* collation is non-default and derives from
85 : * something other than a foreign Var */
86 : } FDWCollateState;
87 :
88 : typedef struct foreign_loc_cxt
89 : {
90 : Oid collation; /* OID of current collation, if any */
91 : FDWCollateState state; /* state of current collation choice */
92 : } foreign_loc_cxt;
93 :
94 : /*
95 : * Context for deparseExpr
96 : */
97 : typedef struct deparse_expr_cxt
98 : {
99 : PlannerInfo *root; /* global planner state */
100 : RelOptInfo *foreignrel; /* the foreign relation we are planning for */
101 : RelOptInfo *scanrel; /* the underlying scan relation. Same as
102 : * foreignrel, when that represents a join or
103 : * a base relation. */
104 : StringInfo buf; /* output buffer to append to */
105 : List **params_list; /* exprs that will become remote Params */
106 : } deparse_expr_cxt;
107 :
108 : #define REL_ALIAS_PREFIX "r"
109 : /* Handy macro to add relation name qualification */
110 : #define ADD_REL_QUALIFIER(buf, varno) \
111 : appendStringInfo((buf), "%s%d.", REL_ALIAS_PREFIX, (varno))
112 : #define SUBQUERY_REL_ALIAS_PREFIX "s"
113 : #define SUBQUERY_COL_ALIAS_PREFIX "c"
114 :
115 : /*
116 : * Functions to determine whether an expression can be evaluated safely on
117 : * remote server.
118 : */
119 : static bool foreign_expr_walker(Node *node,
120 : foreign_glob_cxt *glob_cxt,
121 : foreign_loc_cxt *outer_cxt);
122 : static char *deparse_type_name(Oid type_oid, int32 typemod);
123 :
124 : /*
125 : * Functions to construct string representation of a node tree.
126 : */
127 : static void deparseTargetList(StringInfo buf,
128 : RangeTblEntry *rte,
129 : Index rtindex,
130 : Relation rel,
131 : bool is_returning,
132 : Bitmapset *attrs_used,
133 : bool qualify_col,
134 : List **retrieved_attrs);
135 : static void deparseExplicitTargetList(List *tlist,
136 : bool is_returning,
137 : List **retrieved_attrs,
138 : deparse_expr_cxt *context);
139 : static void deparseSubqueryTargetList(deparse_expr_cxt *context);
140 : static void deparseReturningList(StringInfo buf, RangeTblEntry *rte,
141 : Index rtindex, Relation rel,
142 : bool trig_after_row,
143 : List *withCheckOptionList,
144 : List *returningList,
145 : List **retrieved_attrs);
146 : static void deparseColumnRef(StringInfo buf, int varno, int varattno,
147 : RangeTblEntry *rte, bool qualify_col);
148 : static void deparseRelation(StringInfo buf, Relation rel);
149 : static void deparseExpr(Expr *expr, deparse_expr_cxt *context);
150 : static void deparseVar(Var *node, deparse_expr_cxt *context);
151 : static void deparseConst(Const *node, deparse_expr_cxt *context, int showtype);
152 : static void deparseParam(Param *node, deparse_expr_cxt *context);
153 : static void deparseArrayRef(ArrayRef *node, deparse_expr_cxt *context);
154 : static void deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context);
155 : static void deparseOpExpr(OpExpr *node, deparse_expr_cxt *context);
156 : static void deparseOperatorName(StringInfo buf, Form_pg_operator opform);
157 : static void deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context);
158 : static void deparseScalarArrayOpExpr(ScalarArrayOpExpr *node,
159 : deparse_expr_cxt *context);
160 : static void deparseRelabelType(RelabelType *node, deparse_expr_cxt *context);
161 : static void deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context);
162 : static void deparseNullTest(NullTest *node, deparse_expr_cxt *context);
163 : static void deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context);
164 : static void printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod,
165 : deparse_expr_cxt *context);
166 : static void printRemotePlaceholder(Oid paramtype, int32 paramtypmod,
167 : deparse_expr_cxt *context);
168 : static void deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs,
169 : deparse_expr_cxt *context);
170 : static void deparseLockingClause(deparse_expr_cxt *context);
171 : static void appendOrderByClause(List *pathkeys, deparse_expr_cxt *context);
172 : static void appendConditions(List *exprs, deparse_expr_cxt *context);
173 : static void deparseFromExprForRel(StringInfo buf, PlannerInfo *root,
174 : RelOptInfo *foreignrel, bool use_alias,
175 : Index ignore_rel, List **ignore_conds,
176 : List **params_list);
177 : static void deparseFromExpr(List *quals, deparse_expr_cxt *context);
178 : static void deparseRangeTblRef(StringInfo buf, PlannerInfo *root,
179 : RelOptInfo *foreignrel, bool make_subquery,
180 : Index ignore_rel, List **ignore_conds, List **params_list);
181 : static void deparseAggref(Aggref *node, deparse_expr_cxt *context);
182 : static void appendGroupByClause(List *tlist, deparse_expr_cxt *context);
183 : static void appendAggOrderBy(List *orderList, List *targetList,
184 : deparse_expr_cxt *context);
185 : static void appendFunctionName(Oid funcid, deparse_expr_cxt *context);
186 : static Node *deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
187 : deparse_expr_cxt *context);
188 :
189 : /*
190 : * Helper functions
191 : */
192 : static bool is_subquery_var(Var *node, RelOptInfo *foreignrel,
193 : int *relno, int *colno);
194 : static void get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel,
195 : int *relno, int *colno);
196 :
197 :
198 : /*
199 : * Examine each qual clause in input_conds, and classify them into two groups,
200 : * which are returned as two lists:
201 : * - remote_conds contains expressions that can be evaluated remotely
202 : * - local_conds contains expressions that can't be evaluated remotely
203 : */
204 : void
205 3206 : classifyConditions(PlannerInfo *root,
206 : RelOptInfo *baserel,
207 : List *input_conds,
208 : List **remote_conds,
209 : List **local_conds)
210 : {
211 : ListCell *lc;
212 :
213 3206 : *remote_conds = NIL;
214 3206 : *local_conds = NIL;
215 :
216 4234 : foreach(lc, input_conds)
217 : {
218 1028 : RestrictInfo *ri = lfirst_node(RestrictInfo, lc);
219 :
220 1028 : if (is_foreign_expr(root, baserel, ri->clause))
221 958 : *remote_conds = lappend(*remote_conds, ri);
222 : else
223 70 : *local_conds = lappend(*local_conds, ri);
224 : }
225 3206 : }
226 :
227 : /*
228 : * Returns true if given expr is safe to evaluate on the foreign server.
229 : */
230 : bool
231 3822 : is_foreign_expr(PlannerInfo *root,
232 : RelOptInfo *baserel,
233 : Expr *expr)
234 : {
235 : foreign_glob_cxt glob_cxt;
236 : foreign_loc_cxt loc_cxt;
237 3822 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) (baserel->fdw_private);
238 :
239 : /*
240 : * Check that the expression consists of nodes that are safe to execute
241 : * remotely.
242 : */
243 3822 : glob_cxt.root = root;
244 3822 : glob_cxt.foreignrel = baserel;
245 :
246 : /*
247 : * For an upper relation, use relids from its underneath scan relation,
248 : * because the upperrel's own relids currently aren't set to anything
249 : * meaningful by the core code. For other relation, use their own relids.
250 : */
251 3822 : if (IS_UPPER_REL(baserel))
252 594 : glob_cxt.relids = fpinfo->outerrel->relids;
253 : else
254 3228 : glob_cxt.relids = baserel->relids;
255 3822 : loc_cxt.collation = InvalidOid;
256 3822 : loc_cxt.state = FDW_COLLATE_NONE;
257 3822 : if (!foreign_expr_walker((Node *) expr, &glob_cxt, &loc_cxt))
258 198 : return false;
259 :
260 : /*
261 : * If the expression has a valid collation that does not arise from a
262 : * foreign var, the expression can not be sent over.
263 : */
264 3624 : if (loc_cxt.state == FDW_COLLATE_UNSAFE)
265 4 : return false;
266 :
267 : /*
268 : * An expression which includes any mutable functions can't be sent over
269 : * because its result is not stable. For example, sending now() remote
270 : * side could cause confusion from clock offsets. Future versions might
271 : * be able to make this choice with more granularity. (We check this last
272 : * because it requires a lot of expensive catalog lookups.)
273 : */
274 3620 : if (contain_mutable_functions((Node *) expr))
275 42 : return false;
276 :
277 : /* OK to evaluate on the remote server */
278 3578 : return true;
279 : }
280 :
281 : /*
282 : * Check if expression is safe to execute remotely, and return true if so.
283 : *
284 : * In addition, *outer_cxt is updated with collation information.
285 : *
286 : * We must check that the expression contains only node types we can deparse,
287 : * that all types/functions/operators are safe to send (they are "shippable"),
288 : * and that all collations used in the expression derive from Vars of the
289 : * foreign table. Because of the latter, the logic is pretty close to
290 : * assign_collations_walker() in parse_collate.c, though we can assume here
291 : * that the given expression is valid. Note function mutability is not
292 : * currently considered here.
293 : */
294 : static bool
295 11738 : foreign_expr_walker(Node *node,
296 : foreign_glob_cxt *glob_cxt,
297 : foreign_loc_cxt *outer_cxt)
298 : {
299 11738 : bool check_type = true;
300 : PgFdwRelationInfo *fpinfo;
301 : foreign_loc_cxt inner_cxt;
302 : Oid collation;
303 : FDWCollateState state;
304 :
305 : /* Need do nothing for empty subexpressions */
306 11738 : if (node == NULL)
307 350 : return true;
308 :
309 : /* May need server info from baserel's fdw_private struct */
310 11388 : fpinfo = (PgFdwRelationInfo *) (glob_cxt->foreignrel->fdw_private);
311 :
312 : /* Set up inner_cxt for possible recursion to child nodes */
313 11388 : inner_cxt.collation = InvalidOid;
314 11388 : inner_cxt.state = FDW_COLLATE_NONE;
315 :
316 11388 : switch (nodeTag(node))
317 : {
318 : case T_Var:
319 : {
320 4756 : Var *var = (Var *) node;
321 :
322 : /*
323 : * If the Var is from the foreign table, we consider its
324 : * collation (if any) safe to use. If it is from another
325 : * table, we treat its collation the same way as we would a
326 : * Param's collation, ie it's not safe for it to have a
327 : * non-default collation.
328 : */
329 8920 : if (bms_is_member(var->varno, glob_cxt->relids) &&
330 4164 : var->varlevelsup == 0)
331 : {
332 : /* Var belongs to foreign table */
333 :
334 : /*
335 : * System columns other than ctid and oid should not be
336 : * sent to the remote, since we don't make any effort to
337 : * ensure that local and remote values match (tableoid, in
338 : * particular, almost certainly doesn't match).
339 : */
340 4180 : if (var->varattno < 0 &&
341 28 : var->varattno != SelfItemPointerAttributeNumber &&
342 12 : var->varattno != ObjectIdAttributeNumber)
343 12 : return false;
344 :
345 : /* Else check the collation */
346 4152 : collation = var->varcollid;
347 4152 : state = OidIsValid(collation) ? FDW_COLLATE_SAFE : FDW_COLLATE_NONE;
348 : }
349 : else
350 : {
351 : /* Var belongs to some other table */
352 592 : collation = var->varcollid;
353 592 : if (collation == InvalidOid ||
354 : collation == DEFAULT_COLLATION_OID)
355 : {
356 : /*
357 : * It's noncollatable, or it's safe to combine with a
358 : * collatable foreign Var, so set state to NONE.
359 : */
360 592 : state = FDW_COLLATE_NONE;
361 : }
362 : else
363 : {
364 : /*
365 : * Do not fail right away, since the Var might appear
366 : * in a collation-insensitive context.
367 : */
368 0 : state = FDW_COLLATE_UNSAFE;
369 : }
370 : }
371 : }
372 4744 : break;
373 : case T_Const:
374 : {
375 1074 : Const *c = (Const *) node;
376 :
377 : /*
378 : * If the constant has nondefault collation, either it's of a
379 : * non-builtin type, or it reflects folding of a CollateExpr.
380 : * It's unsafe to send to the remote unless it's used in a
381 : * non-collation-sensitive context.
382 : */
383 1074 : collation = c->constcollid;
384 1074 : if (collation == InvalidOid ||
385 : collation == DEFAULT_COLLATION_OID)
386 1070 : state = FDW_COLLATE_NONE;
387 : else
388 4 : state = FDW_COLLATE_UNSAFE;
389 : }
390 1074 : break;
391 : case T_Param:
392 : {
393 26 : Param *p = (Param *) node;
394 :
395 : /*
396 : * Collation rule is same as for Consts and non-foreign Vars.
397 : */
398 26 : collation = p->paramcollid;
399 26 : if (collation == InvalidOid ||
400 : collation == DEFAULT_COLLATION_OID)
401 26 : state = FDW_COLLATE_NONE;
402 : else
403 0 : state = FDW_COLLATE_UNSAFE;
404 : }
405 26 : break;
406 : case T_ArrayRef:
407 : {
408 2 : ArrayRef *ar = (ArrayRef *) node;
409 :
410 : /* Assignment should not be in restrictions. */
411 2 : if (ar->refassgnexpr != NULL)
412 0 : return false;
413 :
414 : /*
415 : * Recurse to remaining subexpressions. Since the array
416 : * subscripts must yield (noncollatable) integers, they won't
417 : * affect the inner_cxt state.
418 : */
419 2 : if (!foreign_expr_walker((Node *) ar->refupperindexpr,
420 : glob_cxt, &inner_cxt))
421 0 : return false;
422 2 : if (!foreign_expr_walker((Node *) ar->reflowerindexpr,
423 : glob_cxt, &inner_cxt))
424 0 : return false;
425 2 : if (!foreign_expr_walker((Node *) ar->refexpr,
426 : glob_cxt, &inner_cxt))
427 0 : return false;
428 :
429 : /*
430 : * Array subscripting should yield same collation as input,
431 : * but for safety use same logic as for function nodes.
432 : */
433 2 : collation = ar->refcollid;
434 2 : if (collation == InvalidOid)
435 2 : state = FDW_COLLATE_NONE;
436 0 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
437 0 : collation == inner_cxt.collation)
438 0 : state = FDW_COLLATE_SAFE;
439 0 : else if (collation == DEFAULT_COLLATION_OID)
440 0 : state = FDW_COLLATE_NONE;
441 : else
442 0 : state = FDW_COLLATE_UNSAFE;
443 : }
444 2 : break;
445 : case T_FuncExpr:
446 : {
447 212 : FuncExpr *fe = (FuncExpr *) node;
448 :
449 : /*
450 : * If function used by the expression is not shippable, it
451 : * can't be sent to remote because it might have incompatible
452 : * semantics on remote side.
453 : */
454 212 : if (!is_shippable(fe->funcid, ProcedureRelationId, fpinfo))
455 10 : return false;
456 :
457 : /*
458 : * Recurse to input subexpressions.
459 : */
460 202 : if (!foreign_expr_walker((Node *) fe->args,
461 : glob_cxt, &inner_cxt))
462 12 : return false;
463 :
464 : /*
465 : * If function's input collation is not derived from a foreign
466 : * Var, it can't be sent to remote.
467 : */
468 190 : if (fe->inputcollid == InvalidOid)
469 : /* OK, inputs are all noncollatable */ ;
470 68 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
471 24 : fe->inputcollid != inner_cxt.collation)
472 20 : return false;
473 :
474 : /*
475 : * Detect whether node is introducing a collation not derived
476 : * from a foreign Var. (If so, we just mark it unsafe for now
477 : * rather than immediately returning false, since the parent
478 : * node might not care.)
479 : */
480 170 : collation = fe->funccollid;
481 170 : if (collation == InvalidOid)
482 146 : state = FDW_COLLATE_NONE;
483 48 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
484 24 : collation == inner_cxt.collation)
485 24 : state = FDW_COLLATE_SAFE;
486 0 : else if (collation == DEFAULT_COLLATION_OID)
487 0 : state = FDW_COLLATE_NONE;
488 : else
489 0 : state = FDW_COLLATE_UNSAFE;
490 : }
491 170 : break;
492 : case T_OpExpr:
493 : case T_DistinctExpr: /* struct-equivalent to OpExpr */
494 : {
495 2202 : OpExpr *oe = (OpExpr *) node;
496 :
497 : /*
498 : * Similarly, only shippable operators can be sent to remote.
499 : * (If the operator is shippable, we assume its underlying
500 : * function is too.)
501 : */
502 2202 : if (!is_shippable(oe->opno, OperatorRelationId, fpinfo))
503 22 : return false;
504 :
505 : /*
506 : * Recurse to input subexpressions.
507 : */
508 2180 : if (!foreign_expr_walker((Node *) oe->args,
509 : glob_cxt, &inner_cxt))
510 76 : return false;
511 :
512 : /*
513 : * If operator's input collation is not derived from a foreign
514 : * Var, it can't be sent to remote.
515 : */
516 2104 : if (oe->inputcollid == InvalidOid)
517 : /* OK, inputs are all noncollatable */ ;
518 166 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
519 78 : oe->inputcollid != inner_cxt.collation)
520 10 : return false;
521 :
522 : /* Result-collation handling is same as for functions */
523 2094 : collation = oe->opcollid;
524 2094 : if (collation == InvalidOid)
525 2078 : state = FDW_COLLATE_NONE;
526 32 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
527 16 : collation == inner_cxt.collation)
528 16 : state = FDW_COLLATE_SAFE;
529 0 : else if (collation == DEFAULT_COLLATION_OID)
530 0 : state = FDW_COLLATE_NONE;
531 : else
532 0 : state = FDW_COLLATE_UNSAFE;
533 : }
534 2094 : break;
535 : case T_ScalarArrayOpExpr:
536 : {
537 6 : ScalarArrayOpExpr *oe = (ScalarArrayOpExpr *) node;
538 :
539 : /*
540 : * Again, only shippable operators can be sent to remote.
541 : */
542 6 : if (!is_shippable(oe->opno, OperatorRelationId, fpinfo))
543 0 : return false;
544 :
545 : /*
546 : * Recurse to input subexpressions.
547 : */
548 6 : if (!foreign_expr_walker((Node *) oe->args,
549 : glob_cxt, &inner_cxt))
550 0 : return false;
551 :
552 : /*
553 : * If operator's input collation is not derived from a foreign
554 : * Var, it can't be sent to remote.
555 : */
556 6 : if (oe->inputcollid == InvalidOid)
557 : /* OK, inputs are all noncollatable */ ;
558 0 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
559 0 : oe->inputcollid != inner_cxt.collation)
560 0 : return false;
561 :
562 : /* Output is always boolean and so noncollatable. */
563 6 : collation = InvalidOid;
564 6 : state = FDW_COLLATE_NONE;
565 : }
566 6 : break;
567 : case T_RelabelType:
568 : {
569 82 : RelabelType *r = (RelabelType *) node;
570 :
571 : /*
572 : * Recurse to input subexpression.
573 : */
574 82 : if (!foreign_expr_walker((Node *) r->arg,
575 : glob_cxt, &inner_cxt))
576 0 : return false;
577 :
578 : /*
579 : * RelabelType must not introduce a collation not derived from
580 : * an input foreign Var (same logic as for a real function).
581 : */
582 82 : collation = r->resultcollid;
583 82 : if (collation == InvalidOid)
584 0 : state = FDW_COLLATE_NONE;
585 156 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
586 74 : collation == inner_cxt.collation)
587 64 : state = FDW_COLLATE_SAFE;
588 18 : else if (collation == DEFAULT_COLLATION_OID)
589 6 : state = FDW_COLLATE_NONE;
590 : else
591 12 : state = FDW_COLLATE_UNSAFE;
592 : }
593 82 : break;
594 : case T_BoolExpr:
595 : {
596 64 : BoolExpr *b = (BoolExpr *) node;
597 :
598 : /*
599 : * Recurse to input subexpressions.
600 : */
601 64 : if (!foreign_expr_walker((Node *) b->args,
602 : glob_cxt, &inner_cxt))
603 0 : return false;
604 :
605 : /* Output is always boolean and so noncollatable. */
606 64 : collation = InvalidOid;
607 64 : state = FDW_COLLATE_NONE;
608 : }
609 64 : break;
610 : case T_NullTest:
611 : {
612 54 : NullTest *nt = (NullTest *) node;
613 :
614 : /*
615 : * Recurse to input subexpressions.
616 : */
617 54 : if (!foreign_expr_walker((Node *) nt->arg,
618 : glob_cxt, &inner_cxt))
619 0 : return false;
620 :
621 : /* Output is always boolean and so noncollatable. */
622 54 : collation = InvalidOid;
623 54 : state = FDW_COLLATE_NONE;
624 : }
625 54 : break;
626 : case T_ArrayExpr:
627 : {
628 8 : ArrayExpr *a = (ArrayExpr *) node;
629 :
630 : /*
631 : * Recurse to input subexpressions.
632 : */
633 8 : if (!foreign_expr_walker((Node *) a->elements,
634 : glob_cxt, &inner_cxt))
635 0 : return false;
636 :
637 : /*
638 : * ArrayExpr must not introduce a collation not derived from
639 : * an input foreign Var (same logic as for a function).
640 : */
641 8 : collation = a->array_collid;
642 8 : if (collation == InvalidOid)
643 8 : state = FDW_COLLATE_NONE;
644 0 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
645 0 : collation == inner_cxt.collation)
646 0 : state = FDW_COLLATE_SAFE;
647 0 : else if (collation == DEFAULT_COLLATION_OID)
648 0 : state = FDW_COLLATE_NONE;
649 : else
650 0 : state = FDW_COLLATE_UNSAFE;
651 : }
652 8 : break;
653 : case T_List:
654 : {
655 2468 : List *l = (List *) node;
656 : ListCell *lc;
657 :
658 : /*
659 : * Recurse to component subexpressions.
660 : */
661 7010 : foreach(lc, l)
662 : {
663 4656 : if (!foreign_expr_walker((Node *) lfirst(lc),
664 : glob_cxt, &inner_cxt))
665 114 : return false;
666 : }
667 :
668 : /*
669 : * When processing a list, collation state just bubbles up
670 : * from the list elements.
671 : */
672 2354 : collation = inner_cxt.collation;
673 2354 : state = inner_cxt.state;
674 :
675 : /* Don't apply exprType() to the list. */
676 2354 : check_type = false;
677 : }
678 2354 : break;
679 : case T_Aggref:
680 : {
681 376 : Aggref *agg = (Aggref *) node;
682 : ListCell *lc;
683 :
684 : /* Not safe to pushdown when not in grouping context */
685 376 : if (!IS_UPPER_REL(glob_cxt->foreignrel))
686 0 : return false;
687 :
688 : /* Only non-split aggregates are pushable. */
689 376 : if (agg->aggsplit != AGGSPLIT_SIMPLE)
690 0 : return false;
691 :
692 : /* As usual, it must be shippable. */
693 376 : if (!is_shippable(agg->aggfnoid, ProcedureRelationId, fpinfo))
694 8 : return false;
695 :
696 : /*
697 : * Recurse to input args. aggdirectargs, aggorder and
698 : * aggdistinct are all present in args, so no need to check
699 : * their shippability explicitly.
700 : */
701 666 : foreach(lc, agg->args)
702 : {
703 322 : Node *n = (Node *) lfirst(lc);
704 :
705 : /* If TargetEntry, extract the expression from it */
706 322 : if (IsA(n, TargetEntry))
707 : {
708 322 : TargetEntry *tle = (TargetEntry *) n;
709 :
710 322 : n = (Node *) tle->expr;
711 : }
712 :
713 322 : if (!foreign_expr_walker(n, glob_cxt, &inner_cxt))
714 24 : return false;
715 : }
716 :
717 : /*
718 : * For aggorder elements, check whether the sort operator, if
719 : * specified, is shippable or not.
720 : */
721 344 : if (agg->aggorder)
722 : {
723 : ListCell *lc;
724 :
725 92 : foreach(lc, agg->aggorder)
726 : {
727 52 : SortGroupClause *srt = (SortGroupClause *) lfirst(lc);
728 : Oid sortcoltype;
729 : TypeCacheEntry *typentry;
730 : TargetEntry *tle;
731 :
732 52 : tle = get_sortgroupref_tle(srt->tleSortGroupRef,
733 : agg->args);
734 52 : sortcoltype = exprType((Node *) tle->expr);
735 52 : typentry = lookup_type_cache(sortcoltype,
736 : TYPECACHE_LT_OPR | TYPECACHE_GT_OPR);
737 : /* Check shippability of non-default sort operator. */
738 72 : if (srt->sortop != typentry->lt_opr &&
739 32 : srt->sortop != typentry->gt_opr &&
740 12 : !is_shippable(srt->sortop, OperatorRelationId,
741 : fpinfo))
742 8 : return false;
743 : }
744 : }
745 :
746 : /* Check aggregate filter */
747 336 : if (!foreign_expr_walker((Node *) agg->aggfilter,
748 : glob_cxt, &inner_cxt))
749 4 : return false;
750 :
751 : /*
752 : * If aggregate's input collation is not derived from a
753 : * foreign Var, it can't be sent to remote.
754 : */
755 332 : if (agg->inputcollid == InvalidOid)
756 : /* OK, inputs are all noncollatable */ ;
757 48 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
758 24 : agg->inputcollid != inner_cxt.collation)
759 0 : return false;
760 :
761 : /*
762 : * Detect whether node is introducing a collation not derived
763 : * from a foreign Var. (If so, we just mark it unsafe for now
764 : * rather than immediately returning false, since the parent
765 : * node might not care.)
766 : */
767 332 : collation = agg->aggcollid;
768 332 : if (collation == InvalidOid)
769 330 : state = FDW_COLLATE_NONE;
770 4 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
771 2 : collation == inner_cxt.collation)
772 2 : state = FDW_COLLATE_SAFE;
773 0 : else if (collation == DEFAULT_COLLATION_OID)
774 0 : state = FDW_COLLATE_NONE;
775 : else
776 0 : state = FDW_COLLATE_UNSAFE;
777 : }
778 332 : break;
779 : default:
780 :
781 : /*
782 : * If it's anything else, assume it's unsafe. This list can be
783 : * expanded later, but don't forget to add deparse support below.
784 : */
785 58 : return false;
786 : }
787 :
788 : /*
789 : * If result type of given expression is not shippable, it can't be sent
790 : * to remote because it might have incompatible semantics on remote side.
791 : */
792 11010 : if (check_type && !is_shippable(exprType(node), TypeRelationId, fpinfo))
793 50 : return false;
794 :
795 : /*
796 : * Now, merge my collation information into my parent's state.
797 : */
798 10960 : if (state > outer_cxt->state)
799 : {
800 : /* Override previous parent state */
801 530 : outer_cxt->collation = collation;
802 530 : outer_cxt->state = state;
803 : }
804 10430 : else if (state == outer_cxt->state)
805 : {
806 : /* Merge, or detect error if there's a collation conflict */
807 10370 : switch (state)
808 : {
809 : case FDW_COLLATE_NONE:
810 : /* Nothing + nothing is still nothing */
811 10364 : break;
812 : case FDW_COLLATE_SAFE:
813 4 : if (collation != outer_cxt->collation)
814 : {
815 : /*
816 : * Non-default collation always beats default.
817 : */
818 0 : if (outer_cxt->collation == DEFAULT_COLLATION_OID)
819 : {
820 : /* Override previous parent state */
821 0 : outer_cxt->collation = collation;
822 : }
823 0 : else if (collation != DEFAULT_COLLATION_OID)
824 : {
825 : /*
826 : * Conflict; show state as indeterminate. We don't
827 : * want to "return false" right away, since parent
828 : * node might not care about collation.
829 : */
830 0 : outer_cxt->state = FDW_COLLATE_UNSAFE;
831 : }
832 : }
833 4 : break;
834 : case FDW_COLLATE_UNSAFE:
835 : /* We're still conflicted ... */
836 2 : break;
837 : }
838 : }
839 :
840 : /* It looks OK */
841 10960 : return true;
842 : }
843 :
844 : /*
845 : * Convert type OID + typmod info into a type name we can ship to the remote
846 : * server. Someplace else had better have verified that this type name is
847 : * expected to be known on the remote end.
848 : *
849 : * This is almost just format_type_with_typemod(), except that if left to its
850 : * own devices, that function will make schema-qualification decisions based
851 : * on the local search_path, which is wrong. We must schema-qualify all
852 : * type names that are not in pg_catalog. We assume here that built-in types
853 : * are all in pg_catalog and need not be qualified; otherwise, qualify.
854 : */
855 : static char *
856 494 : deparse_type_name(Oid type_oid, int32 typemod)
857 : {
858 494 : bits16 flags = FORMAT_TYPE_TYPEMOD_GIVEN;
859 :
860 494 : if (!is_builtin(type_oid))
861 0 : flags |= FORMAT_TYPE_FORCE_QUALIFY;
862 :
863 494 : return format_type_extended(type_oid, typemod, flags);
864 : }
865 :
866 : /*
867 : * Build the targetlist for given relation to be deparsed as SELECT clause.
868 : *
869 : * The output targetlist contains the columns that need to be fetched from the
870 : * foreign server for the given relation. If foreignrel is an upper relation,
871 : * then the output targetlist can also contain expressions to be evaluated on
872 : * foreign server.
873 : */
874 : List *
875 956 : build_tlist_to_deparse(RelOptInfo *foreignrel)
876 : {
877 956 : List *tlist = NIL;
878 956 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
879 : ListCell *lc;
880 :
881 : /*
882 : * For an upper relation, we have already built the target list while
883 : * checking shippability, so just return that.
884 : */
885 956 : if (IS_UPPER_REL(foreignrel))
886 246 : return fpinfo->grouped_tlist;
887 :
888 : /*
889 : * We require columns specified in foreignrel->reltarget->exprs and those
890 : * required for evaluating the local conditions.
891 : */
892 710 : tlist = add_to_flat_tlist(tlist,
893 710 : pull_var_clause((Node *) foreignrel->reltarget->exprs,
894 : PVC_RECURSE_PLACEHOLDERS));
895 746 : foreach(lc, fpinfo->local_conds)
896 : {
897 36 : RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
898 :
899 36 : tlist = add_to_flat_tlist(tlist,
900 36 : pull_var_clause((Node *) rinfo->clause,
901 : PVC_RECURSE_PLACEHOLDERS));
902 : }
903 :
904 710 : return tlist;
905 : }
906 :
907 : /*
908 : * Deparse SELECT statement for given relation into buf.
909 : *
910 : * tlist contains the list of desired columns to be fetched from foreign server.
911 : * For a base relation fpinfo->attrs_used is used to construct SELECT clause,
912 : * hence the tlist is ignored for a base relation.
913 : *
914 : * remote_conds is the list of conditions to be deparsed into the WHERE clause
915 : * (or, in the case of upper relations, into the HAVING clause).
916 : *
917 : * If params_list is not NULL, it receives a list of Params and other-relation
918 : * Vars used in the clauses; these values must be transmitted to the remote
919 : * server as parameter values.
920 : *
921 : * If params_list is NULL, we're generating the query for EXPLAIN purposes,
922 : * so Params and other-relation Vars should be replaced by dummy values.
923 : *
924 : * pathkeys is the list of pathkeys to order the result by.
925 : *
926 : * is_subquery is the flag to indicate whether to deparse the specified
927 : * relation as a subquery.
928 : *
929 : * List of columns selected is returned in retrieved_attrs.
930 : */
931 : void
932 3048 : deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *rel,
933 : List *tlist, List *remote_conds, List *pathkeys,
934 : bool is_subquery, List **retrieved_attrs,
935 : List **params_list)
936 : {
937 : deparse_expr_cxt context;
938 3048 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
939 : List *quals;
940 :
941 : /*
942 : * We handle relations for foreign tables, joins between those and upper
943 : * relations.
944 : */
945 : Assert(IS_JOIN_REL(rel) || IS_SIMPLE_REL(rel) || IS_UPPER_REL(rel));
946 :
947 : /* Fill portions of context common to upper, join and base relation */
948 3048 : context.buf = buf;
949 3048 : context.root = root;
950 3048 : context.foreignrel = rel;
951 3048 : context.scanrel = IS_UPPER_REL(rel) ? fpinfo->outerrel : rel;
952 3048 : context.params_list = params_list;
953 :
954 : /* Construct SELECT clause */
955 3048 : deparseSelectSql(tlist, is_subquery, retrieved_attrs, &context);
956 :
957 : /*
958 : * For upper relations, the WHERE clause is built from the remote
959 : * conditions of the underlying scan relation; otherwise, we can use the
960 : * supplied list of remote conditions directly.
961 : */
962 3048 : if (IS_UPPER_REL(rel))
963 246 : {
964 : PgFdwRelationInfo *ofpinfo;
965 :
966 246 : ofpinfo = (PgFdwRelationInfo *) fpinfo->outerrel->fdw_private;
967 246 : quals = ofpinfo->remote_conds;
968 : }
969 : else
970 2802 : quals = remote_conds;
971 :
972 : /* Construct FROM and WHERE clauses */
973 3048 : deparseFromExpr(quals, &context);
974 :
975 3048 : if (IS_UPPER_REL(rel))
976 : {
977 : /* Append GROUP BY clause */
978 246 : appendGroupByClause(tlist, &context);
979 :
980 : /* Append HAVING clause */
981 246 : if (remote_conds)
982 : {
983 32 : appendStringInfoString(buf, " HAVING ");
984 32 : appendConditions(remote_conds, &context);
985 : }
986 : }
987 :
988 : /* Add ORDER BY clause if we found any useful pathkeys */
989 3048 : if (pathkeys)
990 776 : appendOrderByClause(pathkeys, &context);
991 :
992 : /* Add any necessary FOR UPDATE/SHARE. */
993 3048 : deparseLockingClause(&context);
994 3048 : }
995 :
996 : /*
997 : * Construct a simple SELECT statement that retrieves desired columns
998 : * of the specified foreign table, and append it to "buf". The output
999 : * contains just "SELECT ... ".
1000 : *
1001 : * We also create an integer List of the columns being retrieved, which is
1002 : * returned to *retrieved_attrs, unless we deparse the specified relation
1003 : * as a subquery.
1004 : *
1005 : * tlist is the list of desired columns. is_subquery is the flag to
1006 : * indicate whether to deparse the specified relation as a subquery.
1007 : * Read prologue of deparseSelectStmtForRel() for details.
1008 : */
1009 : static void
1010 3048 : deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs,
1011 : deparse_expr_cxt *context)
1012 : {
1013 3048 : StringInfo buf = context->buf;
1014 3048 : RelOptInfo *foreignrel = context->foreignrel;
1015 3048 : PlannerInfo *root = context->root;
1016 3048 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1017 :
1018 : /*
1019 : * Construct SELECT list
1020 : */
1021 3048 : appendStringInfoString(buf, "SELECT ");
1022 :
1023 3048 : if (is_subquery)
1024 : {
1025 : /*
1026 : * For a relation that is deparsed as a subquery, emit expressions
1027 : * specified in the relation's reltarget. Note that since this is for
1028 : * the subquery, no need to care about *retrieved_attrs.
1029 : */
1030 56 : deparseSubqueryTargetList(context);
1031 : }
1032 2992 : else if (IS_JOIN_REL(foreignrel) || IS_UPPER_REL(foreignrel))
1033 : {
1034 : /*
1035 : * For a join or upper relation the input tlist gives the list of
1036 : * columns required to be fetched from the foreign server.
1037 : */
1038 956 : deparseExplicitTargetList(tlist, false, retrieved_attrs, context);
1039 : }
1040 : else
1041 : {
1042 : /*
1043 : * For a base relation fpinfo->attrs_used gives the list of columns
1044 : * required to be fetched from the foreign server.
1045 : */
1046 2036 : RangeTblEntry *rte = planner_rt_fetch(foreignrel->relid, root);
1047 :
1048 : /*
1049 : * Core code already has some lock on each rel being planned, so we
1050 : * can use NoLock here.
1051 : */
1052 2036 : Relation rel = heap_open(rte->relid, NoLock);
1053 :
1054 2036 : deparseTargetList(buf, rte, foreignrel->relid, rel, false,
1055 : fpinfo->attrs_used, false, retrieved_attrs);
1056 2036 : heap_close(rel, NoLock);
1057 : }
1058 3048 : }
1059 :
1060 : /*
1061 : * Construct a FROM clause and, if needed, a WHERE clause, and append those to
1062 : * "buf".
1063 : *
1064 : * quals is the list of clauses to be included in the WHERE clause.
1065 : * (These may or may not include RestrictInfo decoration.)
1066 : */
1067 : static void
1068 3048 : deparseFromExpr(List *quals, deparse_expr_cxt *context)
1069 : {
1070 3048 : StringInfo buf = context->buf;
1071 3048 : RelOptInfo *scanrel = context->scanrel;
1072 :
1073 : /* For upper relations, scanrel must be either a joinrel or a baserel */
1074 : Assert(!IS_UPPER_REL(context->foreignrel) ||
1075 : IS_JOIN_REL(scanrel) || IS_SIMPLE_REL(scanrel));
1076 :
1077 : /* Construct FROM clause */
1078 3048 : appendStringInfoString(buf, " FROM ");
1079 6096 : deparseFromExprForRel(buf, context->root, scanrel,
1080 3048 : (bms_membership(scanrel->relids) == BMS_MULTIPLE),
1081 : (Index) 0, NULL, context->params_list);
1082 :
1083 : /* Construct WHERE clause */
1084 3048 : if (quals != NIL)
1085 : {
1086 1194 : appendStringInfoString(buf, " WHERE ");
1087 1194 : appendConditions(quals, context);
1088 : }
1089 3048 : }
1090 :
1091 : /*
1092 : * Emit a target list that retrieves the columns specified in attrs_used.
1093 : * This is used for both SELECT and RETURNING targetlists; the is_returning
1094 : * parameter is true only for a RETURNING targetlist.
1095 : *
1096 : * The tlist text is appended to buf, and we also create an integer List
1097 : * of the columns being retrieved, which is returned to *retrieved_attrs.
1098 : *
1099 : * If qualify_col is true, add relation alias before the column name.
1100 : */
1101 : static void
1102 2538 : deparseTargetList(StringInfo buf,
1103 : RangeTblEntry *rte,
1104 : Index rtindex,
1105 : Relation rel,
1106 : bool is_returning,
1107 : Bitmapset *attrs_used,
1108 : bool qualify_col,
1109 : List **retrieved_attrs)
1110 : {
1111 2538 : TupleDesc tupdesc = RelationGetDescr(rel);
1112 : bool have_wholerow;
1113 : bool first;
1114 : int i;
1115 :
1116 2538 : *retrieved_attrs = NIL;
1117 :
1118 : /* If there's a whole-row reference, we'll need all the columns. */
1119 2538 : have_wholerow = bms_is_member(0 - FirstLowInvalidHeapAttributeNumber,
1120 : attrs_used);
1121 :
1122 2538 : first = true;
1123 18626 : for (i = 1; i <= tupdesc->natts; i++)
1124 : {
1125 16088 : Form_pg_attribute attr = TupleDescAttr(tupdesc, i - 1);
1126 :
1127 : /* Ignore dropped attributes. */
1128 16088 : if (attr->attisdropped)
1129 1470 : continue;
1130 :
1131 25516 : if (have_wholerow ||
1132 10898 : bms_is_member(i - FirstLowInvalidHeapAttributeNumber,
1133 : attrs_used))
1134 : {
1135 8400 : if (!first)
1136 5966 : appendStringInfoString(buf, ", ");
1137 2434 : else if (is_returning)
1138 150 : appendStringInfoString(buf, " RETURNING ");
1139 8400 : first = false;
1140 :
1141 8400 : deparseColumnRef(buf, rtindex, i, rte, qualify_col);
1142 :
1143 8400 : *retrieved_attrs = lappend_int(*retrieved_attrs, i);
1144 : }
1145 : }
1146 :
1147 : /*
1148 : * Add ctid and oid if needed. We currently don't support retrieving any
1149 : * other system columns.
1150 : */
1151 2538 : if (bms_is_member(SelfItemPointerAttributeNumber - FirstLowInvalidHeapAttributeNumber,
1152 : attrs_used))
1153 : {
1154 424 : if (!first)
1155 342 : appendStringInfoString(buf, ", ");
1156 82 : else if (is_returning)
1157 0 : appendStringInfoString(buf, " RETURNING ");
1158 424 : first = false;
1159 :
1160 424 : if (qualify_col)
1161 0 : ADD_REL_QUALIFIER(buf, rtindex);
1162 424 : appendStringInfoString(buf, "ctid");
1163 :
1164 424 : *retrieved_attrs = lappend_int(*retrieved_attrs,
1165 : SelfItemPointerAttributeNumber);
1166 : }
1167 2538 : if (bms_is_member(ObjectIdAttributeNumber - FirstLowInvalidHeapAttributeNumber,
1168 : attrs_used))
1169 : {
1170 4 : if (!first)
1171 4 : appendStringInfoString(buf, ", ");
1172 0 : else if (is_returning)
1173 0 : appendStringInfoString(buf, " RETURNING ");
1174 4 : first = false;
1175 :
1176 4 : if (qualify_col)
1177 0 : ADD_REL_QUALIFIER(buf, rtindex);
1178 4 : appendStringInfoString(buf, "oid");
1179 :
1180 4 : *retrieved_attrs = lappend_int(*retrieved_attrs,
1181 : ObjectIdAttributeNumber);
1182 : }
1183 :
1184 : /* Don't generate bad syntax if no undropped columns */
1185 2538 : if (first && !is_returning)
1186 10 : appendStringInfoString(buf, "NULL");
1187 2538 : }
1188 :
1189 : /*
1190 : * Deparse the appropriate locking clause (FOR UPDATE or FOR SHARE) for a
1191 : * given relation (context->scanrel).
1192 : */
1193 : static void
1194 3048 : deparseLockingClause(deparse_expr_cxt *context)
1195 : {
1196 3048 : StringInfo buf = context->buf;
1197 3048 : PlannerInfo *root = context->root;
1198 3048 : RelOptInfo *rel = context->scanrel;
1199 3048 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
1200 3048 : int relid = -1;
1201 :
1202 10070 : while ((relid = bms_next_member(rel->relids, relid)) >= 0)
1203 : {
1204 : /*
1205 : * Ignore relation if it appears in a lower subquery. Locking clause
1206 : * for such a relation is included in the subquery if necessary.
1207 : */
1208 3974 : if (bms_is_member(relid, fpinfo->lower_subquery_rels))
1209 64 : continue;
1210 :
1211 : /*
1212 : * Add FOR UPDATE/SHARE if appropriate. We apply locking during the
1213 : * initial row fetch, rather than later on as is done for local
1214 : * tables. The extra roundtrips involved in trying to duplicate the
1215 : * local semantics exactly don't seem worthwhile (see also comments
1216 : * for RowMarkType).
1217 : *
1218 : * Note: because we actually run the query as a cursor, this assumes
1219 : * that DECLARE CURSOR ... FOR UPDATE is supported, which it isn't
1220 : * before 8.3.
1221 : */
1222 4336 : if (relid == root->parse->resultRelation &&
1223 614 : (root->parse->commandType == CMD_UPDATE ||
1224 188 : root->parse->commandType == CMD_DELETE))
1225 : {
1226 : /* Relation is UPDATE/DELETE target, so use FOR UPDATE */
1227 426 : appendStringInfoString(buf, " FOR UPDATE");
1228 :
1229 : /* Add the relation alias if we are here for a join relation */
1230 852 : if (IS_JOIN_REL(rel))
1231 84 : appendStringInfo(buf, " OF %s%d", REL_ALIAS_PREFIX, relid);
1232 : }
1233 : else
1234 : {
1235 3484 : PlanRowMark *rc = get_plan_rowmark(root->rowMarks, relid);
1236 :
1237 3484 : if (rc)
1238 : {
1239 : /*
1240 : * Relation is specified as a FOR UPDATE/SHARE target, so
1241 : * handle that. (But we could also see LCS_NONE, meaning this
1242 : * isn't a target relation after all.)
1243 : *
1244 : * For now, just ignore any [NO] KEY specification, since (a)
1245 : * it's not clear what that means for a remote table that we
1246 : * don't have complete information about, and (b) it wouldn't
1247 : * work anyway on older remote servers. Likewise, we don't
1248 : * worry about NOWAIT.
1249 : */
1250 572 : switch (rc->strength)
1251 : {
1252 : case LCS_NONE:
1253 : /* No locking needed */
1254 292 : break;
1255 : case LCS_FORKEYSHARE:
1256 : case LCS_FORSHARE:
1257 68 : appendStringInfoString(buf, " FOR SHARE");
1258 68 : break;
1259 : case LCS_FORNOKEYUPDATE:
1260 : case LCS_FORUPDATE:
1261 212 : appendStringInfoString(buf, " FOR UPDATE");
1262 212 : break;
1263 : }
1264 :
1265 : /* Add the relation alias if we are here for a join relation */
1266 880 : if (bms_membership(rel->relids) == BMS_MULTIPLE &&
1267 308 : rc->strength != LCS_NONE)
1268 168 : appendStringInfo(buf, " OF %s%d", REL_ALIAS_PREFIX, relid);
1269 : }
1270 : }
1271 : }
1272 3048 : }
1273 :
1274 : /*
1275 : * Deparse conditions from the provided list and append them to buf.
1276 : *
1277 : * The conditions in the list are assumed to be ANDed. This function is used to
1278 : * deparse WHERE clauses, JOIN .. ON clauses and HAVING clauses.
1279 : *
1280 : * Depending on the caller, the list elements might be either RestrictInfos
1281 : * or bare clauses.
1282 : */
1283 : static void
1284 2210 : appendConditions(List *exprs, deparse_expr_cxt *context)
1285 : {
1286 : int nestlevel;
1287 : ListCell *lc;
1288 2210 : bool is_first = true;
1289 2210 : StringInfo buf = context->buf;
1290 :
1291 : /* Make sure any constants in the exprs are printed portably */
1292 2210 : nestlevel = set_transmission_modes();
1293 :
1294 5058 : foreach(lc, exprs)
1295 : {
1296 2848 : Expr *expr = (Expr *) lfirst(lc);
1297 :
1298 : /* Extract clause from RestrictInfo, if required */
1299 2848 : if (IsA(expr, RestrictInfo))
1300 2340 : expr = ((RestrictInfo *) expr)->clause;
1301 :
1302 : /* Connect expressions with "AND" and parenthesize each condition. */
1303 2848 : if (!is_first)
1304 638 : appendStringInfoString(buf, " AND ");
1305 :
1306 2848 : appendStringInfoChar(buf, '(');
1307 2848 : deparseExpr(expr, context);
1308 2848 : appendStringInfoChar(buf, ')');
1309 :
1310 2848 : is_first = false;
1311 : }
1312 :
1313 2210 : reset_transmission_modes(nestlevel);
1314 2210 : }
1315 :
1316 : /* Output join name for given join type */
1317 : const char *
1318 1350 : get_jointype_name(JoinType jointype)
1319 : {
1320 1350 : switch (jointype)
1321 : {
1322 : case JOIN_INNER:
1323 770 : return "INNER";
1324 :
1325 : case JOIN_LEFT:
1326 364 : return "LEFT";
1327 :
1328 : case JOIN_RIGHT:
1329 0 : return "RIGHT";
1330 :
1331 : case JOIN_FULL:
1332 216 : return "FULL";
1333 :
1334 : default:
1335 : /* Shouldn't come here, but protect from buggy code. */
1336 0 : elog(ERROR, "unsupported join type %d", jointype);
1337 : }
1338 :
1339 : /* Keep compiler happy */
1340 : return NULL;
1341 : }
1342 :
1343 : /*
1344 : * Deparse given targetlist and append it to context->buf.
1345 : *
1346 : * tlist is list of TargetEntry's which in turn contain Var nodes.
1347 : *
1348 : * retrieved_attrs is the list of continuously increasing integers starting
1349 : * from 1. It has same number of entries as tlist.
1350 : *
1351 : * This is used for both SELECT and RETURNING targetlists; the is_returning
1352 : * parameter is true only for a RETURNING targetlist.
1353 : */
1354 : static void
1355 980 : deparseExplicitTargetList(List *tlist,
1356 : bool is_returning,
1357 : List **retrieved_attrs,
1358 : deparse_expr_cxt *context)
1359 : {
1360 : ListCell *lc;
1361 980 : StringInfo buf = context->buf;
1362 980 : int i = 0;
1363 :
1364 980 : *retrieved_attrs = NIL;
1365 :
1366 4752 : foreach(lc, tlist)
1367 : {
1368 3772 : TargetEntry *tle = lfirst_node(TargetEntry, lc);
1369 :
1370 3772 : if (i > 0)
1371 2808 : appendStringInfoString(buf, ", ");
1372 964 : else if (is_returning)
1373 12 : appendStringInfoString(buf, " RETURNING ");
1374 :
1375 3772 : deparseExpr((Expr *) tle->expr, context);
1376 :
1377 3772 : *retrieved_attrs = lappend_int(*retrieved_attrs, i + 1);
1378 3772 : i++;
1379 : }
1380 :
1381 980 : if (i == 0 && !is_returning)
1382 4 : appendStringInfoString(buf, "NULL");
1383 980 : }
1384 :
1385 : /*
1386 : * Emit expressions specified in the given relation's reltarget.
1387 : *
1388 : * This is used for deparsing the given relation as a subquery.
1389 : */
1390 : static void
1391 56 : deparseSubqueryTargetList(deparse_expr_cxt *context)
1392 : {
1393 56 : StringInfo buf = context->buf;
1394 56 : RelOptInfo *foreignrel = context->foreignrel;
1395 : bool first;
1396 : ListCell *lc;
1397 :
1398 : /* Should only be called in these cases. */
1399 : Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
1400 :
1401 56 : first = true;
1402 120 : foreach(lc, foreignrel->reltarget->exprs)
1403 : {
1404 64 : Node *node = (Node *) lfirst(lc);
1405 :
1406 64 : if (!first)
1407 16 : appendStringInfoString(buf, ", ");
1408 64 : first = false;
1409 :
1410 64 : deparseExpr((Expr *) node, context);
1411 : }
1412 :
1413 : /* Don't generate bad syntax if no expressions */
1414 56 : if (first)
1415 8 : appendStringInfoString(buf, "NULL");
1416 56 : }
1417 :
1418 : /*
1419 : * Construct FROM clause for given relation
1420 : *
1421 : * The function constructs ... JOIN ... ON ... for join relation. For a base
1422 : * relation it just returns schema-qualified tablename, with the appropriate
1423 : * alias if so requested.
1424 : *
1425 : * 'ignore_rel' is either zero or the RT index of a target relation. In the
1426 : * latter case the function constructs FROM clause of UPDATE or USING clause
1427 : * of DELETE; it deparses the join relation as if the relation never contained
1428 : * the target relation, and creates a List of conditions to be deparsed into
1429 : * the top-level WHERE clause, which is returned to *ignore_conds.
1430 : */
1431 : static void
1432 4892 : deparseFromExprForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
1433 : bool use_alias, Index ignore_rel, List **ignore_conds,
1434 : List **params_list)
1435 : {
1436 4892 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1437 :
1438 4892 : if (IS_JOIN_REL(foreignrel))
1439 926 : {
1440 : StringInfoData join_sql_o;
1441 : StringInfoData join_sql_i;
1442 950 : RelOptInfo *outerrel = fpinfo->outerrel;
1443 950 : RelOptInfo *innerrel = fpinfo->innerrel;
1444 950 : bool outerrel_is_target = false;
1445 950 : bool innerrel_is_target = false;
1446 :
1447 950 : if (ignore_rel > 0 && bms_is_member(ignore_rel, foreignrel->relids))
1448 : {
1449 : /*
1450 : * If this is an inner join, add joinclauses to *ignore_conds and
1451 : * set it to empty so that those can be deparsed into the WHERE
1452 : * clause. Note that since the target relation can never be
1453 : * within the nullable side of an outer join, those could safely
1454 : * be pulled up into the WHERE clause (see foreign_join_ok()).
1455 : * Note also that since the target relation is only inner-joined
1456 : * to any other relation in the query, all conditions in the join
1457 : * tree mentioning the target relation could be deparsed into the
1458 : * WHERE clause by doing this recursively.
1459 : */
1460 32 : if (fpinfo->jointype == JOIN_INNER)
1461 : {
1462 28 : *ignore_conds = list_concat(*ignore_conds,
1463 28 : list_copy(fpinfo->joinclauses));
1464 28 : fpinfo->joinclauses = NIL;
1465 : }
1466 :
1467 : /*
1468 : * Check if either of the input relations is the target relation.
1469 : */
1470 32 : if (outerrel->relid == ignore_rel)
1471 24 : outerrel_is_target = true;
1472 8 : else if (innerrel->relid == ignore_rel)
1473 0 : innerrel_is_target = true;
1474 : }
1475 :
1476 : /* Deparse outer relation if not the target relation. */
1477 950 : if (!outerrel_is_target)
1478 : {
1479 926 : initStringInfo(&join_sql_o);
1480 926 : deparseRangeTblRef(&join_sql_o, root, outerrel,
1481 926 : fpinfo->make_outerrel_subquery,
1482 : ignore_rel, ignore_conds, params_list);
1483 :
1484 : /*
1485 : * If inner relation is the target relation, skip deparsing it.
1486 : * Note that since the join of the target relation with any other
1487 : * relation in the query is an inner join and can never be within
1488 : * the nullable side of an outer join, the join could be
1489 : * interchanged with higher-level joins (cf. identity 1 on outer
1490 : * join reordering shown in src/backend/optimizer/README), which
1491 : * means it's safe to skip the target-relation deparsing here.
1492 : */
1493 926 : if (innerrel_is_target)
1494 : {
1495 : Assert(fpinfo->jointype == JOIN_INNER);
1496 : Assert(fpinfo->joinclauses == NIL);
1497 0 : appendStringInfo(buf, "%s", join_sql_o.data);
1498 0 : return;
1499 : }
1500 : }
1501 :
1502 : /* Deparse inner relation if not the target relation. */
1503 950 : if (!innerrel_is_target)
1504 : {
1505 950 : initStringInfo(&join_sql_i);
1506 950 : deparseRangeTblRef(&join_sql_i, root, innerrel,
1507 950 : fpinfo->make_innerrel_subquery,
1508 : ignore_rel, ignore_conds, params_list);
1509 :
1510 : /*
1511 : * If outer relation is the target relation, skip deparsing it.
1512 : * See the above note about safety.
1513 : */
1514 950 : if (outerrel_is_target)
1515 : {
1516 : Assert(fpinfo->jointype == JOIN_INNER);
1517 : Assert(fpinfo->joinclauses == NIL);
1518 24 : appendStringInfo(buf, "%s", join_sql_i.data);
1519 24 : return;
1520 : }
1521 : }
1522 :
1523 : /* Neither of the relations is the target relation. */
1524 : Assert(!outerrel_is_target && !innerrel_is_target);
1525 :
1526 : /*
1527 : * For a join relation FROM clause entry is deparsed as
1528 : *
1529 : * ((outer relation) <join type> (inner relation) ON (joinclauses))
1530 : */
1531 926 : appendStringInfo(buf, "(%s %s JOIN %s ON ", join_sql_o.data,
1532 : get_jointype_name(fpinfo->jointype), join_sql_i.data);
1533 :
1534 : /* Append join clause; (TRUE) if no join clause */
1535 926 : if (fpinfo->joinclauses)
1536 : {
1537 : deparse_expr_cxt context;
1538 :
1539 902 : context.buf = buf;
1540 902 : context.foreignrel = foreignrel;
1541 902 : context.scanrel = foreignrel;
1542 902 : context.root = root;
1543 902 : context.params_list = params_list;
1544 :
1545 902 : appendStringInfoChar(buf, '(');
1546 902 : appendConditions(fpinfo->joinclauses, &context);
1547 902 : appendStringInfoChar(buf, ')');
1548 : }
1549 : else
1550 24 : appendStringInfoString(buf, "(TRUE)");
1551 :
1552 : /* End the FROM clause entry. */
1553 926 : appendStringInfoChar(buf, ')');
1554 : }
1555 : else
1556 : {
1557 3942 : RangeTblEntry *rte = planner_rt_fetch(foreignrel->relid, root);
1558 :
1559 : /*
1560 : * Core code already has some lock on each rel being planned, so we
1561 : * can use NoLock here.
1562 : */
1563 3942 : Relation rel = heap_open(rte->relid, NoLock);
1564 :
1565 3942 : deparseRelation(buf, rel);
1566 :
1567 : /*
1568 : * Add a unique alias to avoid any conflict in relation names due to
1569 : * pulled up subqueries in the query being built for a pushed down
1570 : * join.
1571 : */
1572 3942 : if (use_alias)
1573 1644 : appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, foreignrel->relid);
1574 :
1575 3942 : heap_close(rel, NoLock);
1576 : }
1577 : }
1578 :
1579 : /*
1580 : * Append FROM clause entry for the given relation into buf.
1581 : */
1582 : static void
1583 1876 : deparseRangeTblRef(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
1584 : bool make_subquery, Index ignore_rel, List **ignore_conds,
1585 : List **params_list)
1586 : {
1587 1876 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1588 :
1589 : /* Should only be called in these cases. */
1590 : Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
1591 :
1592 : Assert(fpinfo->local_conds == NIL);
1593 :
1594 : /* If make_subquery is true, deparse the relation as a subquery. */
1595 1876 : if (make_subquery)
1596 : {
1597 : List *retrieved_attrs;
1598 : int ncols;
1599 :
1600 : /*
1601 : * The given relation shouldn't contain the target relation, because
1602 : * this should only happen for input relations for a full join, and
1603 : * such relations can never contain an UPDATE/DELETE target.
1604 : */
1605 : Assert(ignore_rel == 0 ||
1606 : !bms_is_member(ignore_rel, foreignrel->relids));
1607 :
1608 : /* Deparse the subquery representing the relation. */
1609 56 : appendStringInfoChar(buf, '(');
1610 56 : deparseSelectStmtForRel(buf, root, foreignrel, NIL,
1611 : fpinfo->remote_conds, NIL, true,
1612 : &retrieved_attrs, params_list);
1613 56 : appendStringInfoChar(buf, ')');
1614 :
1615 : /* Append the relation alias. */
1616 56 : appendStringInfo(buf, " %s%d", SUBQUERY_REL_ALIAS_PREFIX,
1617 : fpinfo->relation_index);
1618 :
1619 : /*
1620 : * Append the column aliases if needed. Note that the subquery emits
1621 : * expressions specified in the relation's reltarget (see
1622 : * deparseSubqueryTargetList).
1623 : */
1624 56 : ncols = list_length(foreignrel->reltarget->exprs);
1625 56 : if (ncols > 0)
1626 : {
1627 : int i;
1628 :
1629 48 : appendStringInfoChar(buf, '(');
1630 112 : for (i = 1; i <= ncols; i++)
1631 : {
1632 64 : if (i > 1)
1633 16 : appendStringInfoString(buf, ", ");
1634 :
1635 64 : appendStringInfo(buf, "%s%d", SUBQUERY_COL_ALIAS_PREFIX, i);
1636 : }
1637 48 : appendStringInfoChar(buf, ')');
1638 : }
1639 : }
1640 : else
1641 1820 : deparseFromExprForRel(buf, root, foreignrel, true, ignore_rel,
1642 : ignore_conds, params_list);
1643 1876 : }
1644 :
1645 : /*
1646 : * deparse remote INSERT statement
1647 : *
1648 : * The statement text is appended to buf, and we also create an integer List
1649 : * of the columns being retrieved by WITH CHECK OPTION or RETURNING (if any),
1650 : * which is returned to *retrieved_attrs.
1651 : */
1652 : void
1653 156 : deparseInsertSql(StringInfo buf, RangeTblEntry *rte,
1654 : Index rtindex, Relation rel,
1655 : List *targetAttrs, bool doNothing,
1656 : List *withCheckOptionList, List *returningList,
1657 : List **retrieved_attrs)
1658 : {
1659 : AttrNumber pindex;
1660 : bool first;
1661 : ListCell *lc;
1662 :
1663 156 : appendStringInfoString(buf, "INSERT INTO ");
1664 156 : deparseRelation(buf, rel);
1665 :
1666 156 : if (targetAttrs)
1667 : {
1668 156 : appendStringInfoChar(buf, '(');
1669 :
1670 156 : first = true;
1671 682 : foreach(lc, targetAttrs)
1672 : {
1673 526 : int attnum = lfirst_int(lc);
1674 :
1675 526 : if (!first)
1676 370 : appendStringInfoString(buf, ", ");
1677 526 : first = false;
1678 :
1679 526 : deparseColumnRef(buf, rtindex, attnum, rte, false);
1680 : }
1681 :
1682 156 : appendStringInfoString(buf, ") VALUES (");
1683 :
1684 156 : pindex = 1;
1685 156 : first = true;
1686 682 : foreach(lc, targetAttrs)
1687 : {
1688 526 : if (!first)
1689 370 : appendStringInfoString(buf, ", ");
1690 526 : first = false;
1691 :
1692 526 : appendStringInfo(buf, "$%d", pindex);
1693 526 : pindex++;
1694 : }
1695 :
1696 156 : appendStringInfoChar(buf, ')');
1697 : }
1698 : else
1699 0 : appendStringInfoString(buf, " DEFAULT VALUES");
1700 :
1701 156 : if (doNothing)
1702 6 : appendStringInfoString(buf, " ON CONFLICT DO NOTHING");
1703 :
1704 156 : deparseReturningList(buf, rte, rtindex, rel,
1705 156 : rel->trigdesc && rel->trigdesc->trig_insert_after_row,
1706 : withCheckOptionList, returningList, retrieved_attrs);
1707 156 : }
1708 :
1709 : /*
1710 : * deparse remote UPDATE statement
1711 : *
1712 : * The statement text is appended to buf, and we also create an integer List
1713 : * of the columns being retrieved by WITH CHECK OPTION or RETURNING (if any),
1714 : * which is returned to *retrieved_attrs.
1715 : */
1716 : void
1717 62 : deparseUpdateSql(StringInfo buf, RangeTblEntry *rte,
1718 : Index rtindex, Relation rel,
1719 : List *targetAttrs,
1720 : List *withCheckOptionList, List *returningList,
1721 : List **retrieved_attrs)
1722 : {
1723 : AttrNumber pindex;
1724 : bool first;
1725 : ListCell *lc;
1726 :
1727 62 : appendStringInfoString(buf, "UPDATE ");
1728 62 : deparseRelation(buf, rel);
1729 62 : appendStringInfoString(buf, " SET ");
1730 :
1731 62 : pindex = 2; /* ctid is always the first param */
1732 62 : first = true;
1733 124 : foreach(lc, targetAttrs)
1734 : {
1735 62 : int attnum = lfirst_int(lc);
1736 :
1737 62 : if (!first)
1738 0 : appendStringInfoString(buf, ", ");
1739 62 : first = false;
1740 :
1741 62 : deparseColumnRef(buf, rtindex, attnum, rte, false);
1742 62 : appendStringInfo(buf, " = $%d", pindex);
1743 62 : pindex++;
1744 : }
1745 62 : appendStringInfoString(buf, " WHERE ctid = $1");
1746 :
1747 62 : deparseReturningList(buf, rte, rtindex, rel,
1748 62 : rel->trigdesc && rel->trigdesc->trig_update_after_row,
1749 : withCheckOptionList, returningList, retrieved_attrs);
1750 62 : }
1751 :
1752 : /*
1753 : * deparse remote UPDATE statement
1754 : *
1755 : * 'buf' is the output buffer to append the statement to
1756 : * 'rtindex' is the RT index of the associated target relation
1757 : * 'rel' is the relation descriptor for the target relation
1758 : * 'foreignrel' is the RelOptInfo for the target relation or the join relation
1759 : * containing all base relations in the query
1760 : * 'targetlist' is the tlist of the underlying foreign-scan plan node
1761 : * 'targetAttrs' is the target columns of the UPDATE
1762 : * 'remote_conds' is the qual clauses that must be evaluated remotely
1763 : * '*params_list' is an output list of exprs that will become remote Params
1764 : * 'returningList' is the RETURNING targetlist
1765 : * '*retrieved_attrs' is an output list of integers of columns being retrieved
1766 : * by RETURNING (if any)
1767 : */
1768 : void
1769 74 : deparseDirectUpdateSql(StringInfo buf, PlannerInfo *root,
1770 : Index rtindex, Relation rel,
1771 : RelOptInfo *foreignrel,
1772 : List *targetlist,
1773 : List *targetAttrs,
1774 : List *remote_conds,
1775 : List **params_list,
1776 : List *returningList,
1777 : List **retrieved_attrs)
1778 : {
1779 : deparse_expr_cxt context;
1780 : int nestlevel;
1781 : bool first;
1782 : ListCell *lc;
1783 74 : RangeTblEntry *rte = planner_rt_fetch(rtindex, root);
1784 :
1785 : /* Set up context struct for recursion */
1786 74 : context.root = root;
1787 74 : context.foreignrel = foreignrel;
1788 74 : context.scanrel = foreignrel;
1789 74 : context.buf = buf;
1790 74 : context.params_list = params_list;
1791 :
1792 74 : appendStringInfoString(buf, "UPDATE ");
1793 74 : deparseRelation(buf, rel);
1794 74 : if (foreignrel->reloptkind == RELOPT_JOINREL)
1795 12 : appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, rtindex);
1796 74 : appendStringInfoString(buf, " SET ");
1797 :
1798 : /* Make sure any constants in the exprs are printed portably */
1799 74 : nestlevel = set_transmission_modes();
1800 :
1801 74 : first = true;
1802 164 : foreach(lc, targetAttrs)
1803 : {
1804 90 : int attnum = lfirst_int(lc);
1805 90 : TargetEntry *tle = get_tle_by_resno(targetlist, attnum);
1806 :
1807 90 : if (!tle)
1808 0 : elog(ERROR, "attribute number %d not found in UPDATE targetlist",
1809 : attnum);
1810 :
1811 90 : if (!first)
1812 16 : appendStringInfoString(buf, ", ");
1813 90 : first = false;
1814 :
1815 90 : deparseColumnRef(buf, rtindex, attnum, rte, false);
1816 90 : appendStringInfoString(buf, " = ");
1817 90 : deparseExpr((Expr *) tle->expr, &context);
1818 : }
1819 :
1820 74 : reset_transmission_modes(nestlevel);
1821 :
1822 74 : if (foreignrel->reloptkind == RELOPT_JOINREL)
1823 : {
1824 12 : List *ignore_conds = NIL;
1825 :
1826 12 : appendStringInfo(buf, " FROM ");
1827 12 : deparseFromExprForRel(buf, root, foreignrel, true, rtindex,
1828 : &ignore_conds, params_list);
1829 12 : remote_conds = list_concat(remote_conds, ignore_conds);
1830 : }
1831 :
1832 74 : if (remote_conds)
1833 : {
1834 54 : appendStringInfoString(buf, " WHERE ");
1835 54 : appendConditions(remote_conds, &context);
1836 : }
1837 :
1838 74 : if (foreignrel->reloptkind == RELOPT_JOINREL)
1839 12 : deparseExplicitTargetList(returningList, true, retrieved_attrs,
1840 : &context);
1841 : else
1842 62 : deparseReturningList(buf, rte, rtindex, rel, false,
1843 : NIL, returningList, retrieved_attrs);
1844 74 : }
1845 :
1846 : /*
1847 : * deparse remote DELETE statement
1848 : *
1849 : * The statement text is appended to buf, and we also create an integer List
1850 : * of the columns being retrieved by RETURNING (if any), which is returned
1851 : * to *retrieved_attrs.
1852 : */
1853 : void
1854 18 : deparseDeleteSql(StringInfo buf, RangeTblEntry *rte,
1855 : Index rtindex, Relation rel,
1856 : List *returningList,
1857 : List **retrieved_attrs)
1858 : {
1859 18 : appendStringInfoString(buf, "DELETE FROM ");
1860 18 : deparseRelation(buf, rel);
1861 18 : appendStringInfoString(buf, " WHERE ctid = $1");
1862 :
1863 18 : deparseReturningList(buf, rte, rtindex, rel,
1864 18 : rel->trigdesc && rel->trigdesc->trig_delete_after_row,
1865 : NIL, returningList, retrieved_attrs);
1866 18 : }
1867 :
1868 : /*
1869 : * deparse remote DELETE statement
1870 : *
1871 : * 'buf' is the output buffer to append the statement to
1872 : * 'rtindex' is the RT index of the associated target relation
1873 : * 'rel' is the relation descriptor for the target relation
1874 : * 'foreignrel' is the RelOptInfo for the target relation or the join relation
1875 : * containing all base relations in the query
1876 : * 'remote_conds' is the qual clauses that must be evaluated remotely
1877 : * '*params_list' is an output list of exprs that will become remote Params
1878 : * 'returningList' is the RETURNING targetlist
1879 : * '*retrieved_attrs' is an output list of integers of columns being retrieved
1880 : * by RETURNING (if any)
1881 : */
1882 : void
1883 78 : deparseDirectDeleteSql(StringInfo buf, PlannerInfo *root,
1884 : Index rtindex, Relation rel,
1885 : RelOptInfo *foreignrel,
1886 : List *remote_conds,
1887 : List **params_list,
1888 : List *returningList,
1889 : List **retrieved_attrs)
1890 : {
1891 : deparse_expr_cxt context;
1892 :
1893 : /* Set up context struct for recursion */
1894 78 : context.root = root;
1895 78 : context.foreignrel = foreignrel;
1896 78 : context.scanrel = foreignrel;
1897 78 : context.buf = buf;
1898 78 : context.params_list = params_list;
1899 :
1900 78 : appendStringInfoString(buf, "DELETE FROM ");
1901 78 : deparseRelation(buf, rel);
1902 78 : if (foreignrel->reloptkind == RELOPT_JOINREL)
1903 12 : appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, rtindex);
1904 :
1905 78 : if (foreignrel->reloptkind == RELOPT_JOINREL)
1906 : {
1907 12 : List *ignore_conds = NIL;
1908 :
1909 12 : appendStringInfo(buf, " USING ");
1910 12 : deparseFromExprForRel(buf, root, foreignrel, true, rtindex,
1911 : &ignore_conds, params_list);
1912 12 : remote_conds = list_concat(remote_conds, ignore_conds);
1913 : }
1914 :
1915 78 : if (remote_conds)
1916 : {
1917 28 : appendStringInfoString(buf, " WHERE ");
1918 28 : appendConditions(remote_conds, &context);
1919 : }
1920 :
1921 78 : if (foreignrel->reloptkind == RELOPT_JOINREL)
1922 12 : deparseExplicitTargetList(returningList, true, retrieved_attrs,
1923 : &context);
1924 : else
1925 66 : deparseReturningList(buf, planner_rt_fetch(rtindex, root),
1926 : rtindex, rel, false,
1927 : NIL, returningList, retrieved_attrs);
1928 78 : }
1929 :
1930 : /*
1931 : * Add a RETURNING clause, if needed, to an INSERT/UPDATE/DELETE.
1932 : */
1933 : static void
1934 364 : deparseReturningList(StringInfo buf, RangeTblEntry *rte,
1935 : Index rtindex, Relation rel,
1936 : bool trig_after_row,
1937 : List *withCheckOptionList,
1938 : List *returningList,
1939 : List **retrieved_attrs)
1940 : {
1941 364 : Bitmapset *attrs_used = NULL;
1942 :
1943 364 : if (trig_after_row)
1944 : {
1945 : /* whole-row reference acquires all non-system columns */
1946 40 : attrs_used =
1947 40 : bms_make_singleton(0 - FirstLowInvalidHeapAttributeNumber);
1948 : }
1949 :
1950 364 : if (withCheckOptionList != NIL)
1951 : {
1952 : /*
1953 : * We need the attrs, non-system and system, mentioned in the local
1954 : * query's WITH CHECK OPTION list.
1955 : *
1956 : * Note: we do this to ensure that WCO constraints will be evaluated
1957 : * on the data actually inserted/updated on the remote side, which
1958 : * might differ from the data supplied by the core code, for example
1959 : * as a result of remote triggers.
1960 : */
1961 28 : pull_varattnos((Node *) withCheckOptionList, rtindex,
1962 : &attrs_used);
1963 : }
1964 :
1965 364 : if (returningList != NIL)
1966 : {
1967 : /*
1968 : * We need the attrs, non-system and system, mentioned in the local
1969 : * query's RETURNING list.
1970 : */
1971 96 : pull_varattnos((Node *) returningList, rtindex,
1972 : &attrs_used);
1973 : }
1974 :
1975 364 : if (attrs_used != NULL)
1976 162 : deparseTargetList(buf, rte, rtindex, rel, true, attrs_used, false,
1977 : retrieved_attrs);
1978 : else
1979 202 : *retrieved_attrs = NIL;
1980 364 : }
1981 :
1982 : /*
1983 : * Construct SELECT statement to acquire size in blocks of given relation.
1984 : *
1985 : * Note: we use local definition of block size, not remote definition.
1986 : * This is perhaps debatable.
1987 : *
1988 : * Note: pg_relation_size() exists in 8.1 and later.
1989 : */
1990 : void
1991 46 : deparseAnalyzeSizeSql(StringInfo buf, Relation rel)
1992 : {
1993 : StringInfoData relname;
1994 :
1995 : /* We'll need the remote relation name as a literal. */
1996 46 : initStringInfo(&relname);
1997 46 : deparseRelation(&relname, rel);
1998 :
1999 46 : appendStringInfoString(buf, "SELECT pg_catalog.pg_relation_size(");
2000 46 : deparseStringLiteral(buf, relname.data);
2001 46 : appendStringInfo(buf, "::pg_catalog.regclass) / %d", BLCKSZ);
2002 46 : }
2003 :
2004 : /*
2005 : * Construct SELECT statement to acquire sample rows of given relation.
2006 : *
2007 : * SELECT command is appended to buf, and list of columns retrieved
2008 : * is returned to *retrieved_attrs.
2009 : */
2010 : void
2011 46 : deparseAnalyzeSql(StringInfo buf, Relation rel, List **retrieved_attrs)
2012 : {
2013 46 : Oid relid = RelationGetRelid(rel);
2014 46 : TupleDesc tupdesc = RelationGetDescr(rel);
2015 : int i;
2016 : char *colname;
2017 : List *options;
2018 : ListCell *lc;
2019 46 : bool first = true;
2020 :
2021 46 : *retrieved_attrs = NIL;
2022 :
2023 46 : appendStringInfoString(buf, "SELECT ");
2024 192 : for (i = 0; i < tupdesc->natts; i++)
2025 : {
2026 : /* Ignore dropped columns. */
2027 146 : if (TupleDescAttr(tupdesc, i)->attisdropped)
2028 2 : continue;
2029 :
2030 144 : if (!first)
2031 98 : appendStringInfoString(buf, ", ");
2032 144 : first = false;
2033 :
2034 : /* Use attribute name or column_name option. */
2035 144 : colname = NameStr(TupleDescAttr(tupdesc, i)->attname);
2036 144 : options = GetForeignColumnOptions(relid, i + 1);
2037 :
2038 144 : foreach(lc, options)
2039 : {
2040 2 : DefElem *def = (DefElem *) lfirst(lc);
2041 :
2042 2 : if (strcmp(def->defname, "column_name") == 0)
2043 : {
2044 2 : colname = defGetString(def);
2045 2 : break;
2046 : }
2047 : }
2048 :
2049 144 : appendStringInfoString(buf, quote_identifier(colname));
2050 :
2051 144 : *retrieved_attrs = lappend_int(*retrieved_attrs, i + 1);
2052 : }
2053 :
2054 : /* Don't generate bad syntax for zero-column relation. */
2055 46 : if (first)
2056 0 : appendStringInfoString(buf, "NULL");
2057 :
2058 : /*
2059 : * Construct FROM clause
2060 : */
2061 46 : appendStringInfoString(buf, " FROM ");
2062 46 : deparseRelation(buf, rel);
2063 46 : }
2064 :
2065 : /*
2066 : * Construct name to use for given column, and emit it into buf.
2067 : * If it has a column_name FDW option, use that instead of attribute name.
2068 : *
2069 : * If qualify_col is true, qualify column name with the alias of relation.
2070 : */
2071 : static void
2072 17618 : deparseColumnRef(StringInfo buf, int varno, int varattno, RangeTblEntry *rte,
2073 : bool qualify_col)
2074 : {
2075 : /* We support fetching the remote side's CTID and OID. */
2076 17618 : if (varattno == SelfItemPointerAttributeNumber)
2077 : {
2078 94 : if (qualify_col)
2079 90 : ADD_REL_QUALIFIER(buf, varno);
2080 94 : appendStringInfoString(buf, "ctid");
2081 : }
2082 17524 : else if (varattno == ObjectIdAttributeNumber)
2083 : {
2084 0 : if (qualify_col)
2085 0 : ADD_REL_QUALIFIER(buf, varno);
2086 0 : appendStringInfoString(buf, "oid");
2087 : }
2088 17524 : else if (varattno < 0)
2089 : {
2090 : /*
2091 : * All other system attributes are fetched as 0, except for table OID,
2092 : * which is fetched as the local table OID. However, we must be
2093 : * careful; the table could be beneath an outer join, in which case it
2094 : * must go to NULL whenever the rest of the row does.
2095 : */
2096 0 : Oid fetchval = 0;
2097 :
2098 0 : if (varattno == TableOidAttributeNumber)
2099 0 : fetchval = rte->relid;
2100 :
2101 0 : if (qualify_col)
2102 : {
2103 0 : appendStringInfoString(buf, "CASE WHEN (");
2104 0 : ADD_REL_QUALIFIER(buf, varno);
2105 0 : appendStringInfo(buf, "*)::text IS NOT NULL THEN %u END", fetchval);
2106 : }
2107 : else
2108 0 : appendStringInfo(buf, "%u", fetchval);
2109 : }
2110 17524 : else if (varattno == 0)
2111 : {
2112 : /* Whole row reference */
2113 : Relation rel;
2114 : Bitmapset *attrs_used;
2115 :
2116 : /* Required only to be passed down to deparseTargetList(). */
2117 : List *retrieved_attrs;
2118 :
2119 : /*
2120 : * The lock on the relation will be held by upper callers, so it's
2121 : * fine to open it with no lock here.
2122 : */
2123 340 : rel = heap_open(rte->relid, NoLock);
2124 :
2125 : /*
2126 : * The local name of the foreign table can not be recognized by the
2127 : * foreign server and the table it references on foreign server might
2128 : * have different column ordering or different columns than those
2129 : * declared locally. Hence we have to deparse whole-row reference as
2130 : * ROW(columns referenced locally). Construct this by deparsing a
2131 : * "whole row" attribute.
2132 : */
2133 340 : attrs_used = bms_add_member(NULL,
2134 : 0 - FirstLowInvalidHeapAttributeNumber);
2135 :
2136 : /*
2137 : * In case the whole-row reference is under an outer join then it has
2138 : * to go NULL whenever the rest of the row goes NULL. Deparsing a join
2139 : * query would always involve multiple relations, thus qualify_col
2140 : * would be true.
2141 : */
2142 340 : if (qualify_col)
2143 : {
2144 332 : appendStringInfoString(buf, "CASE WHEN (");
2145 332 : ADD_REL_QUALIFIER(buf, varno);
2146 332 : appendStringInfoString(buf, "*)::text IS NOT NULL THEN ");
2147 : }
2148 :
2149 340 : appendStringInfoString(buf, "ROW(");
2150 340 : deparseTargetList(buf, rte, varno, rel, false, attrs_used, qualify_col,
2151 : &retrieved_attrs);
2152 340 : appendStringInfoChar(buf, ')');
2153 :
2154 : /* Complete the CASE WHEN statement started above. */
2155 340 : if (qualify_col)
2156 332 : appendStringInfoString(buf, " END");
2157 :
2158 340 : heap_close(rel, NoLock);
2159 340 : bms_free(attrs_used);
2160 : }
2161 : else
2162 : {
2163 17184 : char *colname = NULL;
2164 : List *options;
2165 : ListCell *lc;
2166 :
2167 : /* varno must not be any of OUTER_VAR, INNER_VAR and INDEX_VAR. */
2168 : Assert(!IS_SPECIAL_VARNO(varno));
2169 :
2170 : /*
2171 : * If it's a column of a foreign table, and it has the column_name FDW
2172 : * option, use that value.
2173 : */
2174 17184 : options = GetForeignColumnOptions(rte->relid, varattno);
2175 17184 : foreach(lc, options)
2176 : {
2177 4404 : DefElem *def = (DefElem *) lfirst(lc);
2178 :
2179 4404 : if (strcmp(def->defname, "column_name") == 0)
2180 : {
2181 4404 : colname = defGetString(def);
2182 4404 : break;
2183 : }
2184 : }
2185 :
2186 : /*
2187 : * If it's a column of a regular table or it doesn't have column_name
2188 : * FDW option, use attribute name.
2189 : */
2190 17184 : if (colname == NULL)
2191 12780 : colname = get_attname(rte->relid, varattno, false);
2192 :
2193 17184 : if (qualify_col)
2194 7444 : ADD_REL_QUALIFIER(buf, varno);
2195 :
2196 17184 : appendStringInfoString(buf, quote_identifier(colname));
2197 : }
2198 17618 : }
2199 :
2200 : /*
2201 : * Append remote name of specified foreign table to buf.
2202 : * Use value of table_name FDW option (if any) instead of relation's name.
2203 : * Similarly, schema_name FDW option overrides schema name.
2204 : */
2205 : static void
2206 4422 : deparseRelation(StringInfo buf, Relation rel)
2207 : {
2208 : ForeignTable *table;
2209 4422 : const char *nspname = NULL;
2210 4422 : const char *relname = NULL;
2211 : ListCell *lc;
2212 :
2213 : /* obtain additional catalog information. */
2214 4422 : table = GetForeignTable(RelationGetRelid(rel));
2215 :
2216 : /*
2217 : * Use value of FDW options if any, instead of the name of object itself.
2218 : */
2219 14356 : foreach(lc, table->options)
2220 : {
2221 9934 : DefElem *def = (DefElem *) lfirst(lc);
2222 :
2223 9934 : if (strcmp(def->defname, "schema_name") == 0)
2224 3062 : nspname = defGetString(def);
2225 6872 : else if (strcmp(def->defname, "table_name") == 0)
2226 4422 : relname = defGetString(def);
2227 : }
2228 :
2229 : /*
2230 : * Note: we could skip printing the schema name if it's pg_catalog, but
2231 : * that doesn't seem worth the trouble.
2232 : */
2233 4422 : if (nspname == NULL)
2234 1360 : nspname = get_namespace_name(RelationGetNamespace(rel));
2235 4422 : if (relname == NULL)
2236 0 : relname = RelationGetRelationName(rel);
2237 :
2238 4422 : appendStringInfo(buf, "%s.%s",
2239 : quote_identifier(nspname), quote_identifier(relname));
2240 4422 : }
2241 :
2242 : /*
2243 : * Append a SQL string literal representing "val" to buf.
2244 : */
2245 : void
2246 438 : deparseStringLiteral(StringInfo buf, const char *val)
2247 : {
2248 : const char *valptr;
2249 :
2250 : /*
2251 : * Rather than making assumptions about the remote server's value of
2252 : * standard_conforming_strings, always use E'foo' syntax if there are any
2253 : * backslashes. This will fail on remote servers before 8.1, but those
2254 : * are long out of support.
2255 : */
2256 438 : if (strchr(val, '\\') != NULL)
2257 2 : appendStringInfoChar(buf, ESCAPE_STRING_SYNTAX);
2258 438 : appendStringInfoChar(buf, '\'');
2259 3322 : for (valptr = val; *valptr; valptr++)
2260 : {
2261 2884 : char ch = *valptr;
2262 :
2263 2884 : if (SQL_STR_DOUBLE(ch, true))
2264 4 : appendStringInfoChar(buf, ch);
2265 2884 : appendStringInfoChar(buf, ch);
2266 : }
2267 438 : appendStringInfoChar(buf, '\'');
2268 438 : }
2269 :
2270 : /*
2271 : * Deparse given expression into context->buf.
2272 : *
2273 : * This function must support all the same node types that foreign_expr_walker
2274 : * accepts.
2275 : *
2276 : * Note: unlike ruleutils.c, we just use a simple hard-wired parenthesization
2277 : * scheme: anything more complex than a Var, Const, function call or cast
2278 : * should be self-parenthesized.
2279 : */
2280 : static void
2281 15256 : deparseExpr(Expr *node, deparse_expr_cxt *context)
2282 : {
2283 15256 : if (node == NULL)
2284 0 : return;
2285 :
2286 15256 : switch (nodeTag(node))
2287 : {
2288 : case T_Var:
2289 8988 : deparseVar((Var *) node, context);
2290 8988 : break;
2291 : case T_Const:
2292 2182 : deparseConst((Const *) node, context, 0);
2293 2182 : break;
2294 : case T_Param:
2295 40 : deparseParam((Param *) node, context);
2296 40 : break;
2297 : case T_ArrayRef:
2298 2 : deparseArrayRef((ArrayRef *) node, context);
2299 2 : break;
2300 : case T_FuncExpr:
2301 96 : deparseFuncExpr((FuncExpr *) node, context);
2302 96 : break;
2303 : case T_OpExpr:
2304 3382 : deparseOpExpr((OpExpr *) node, context);
2305 3382 : break;
2306 : case T_DistinctExpr:
2307 2 : deparseDistinctExpr((DistinctExpr *) node, context);
2308 2 : break;
2309 : case T_ScalarArrayOpExpr:
2310 8 : deparseScalarArrayOpExpr((ScalarArrayOpExpr *) node, context);
2311 8 : break;
2312 : case T_RelabelType:
2313 60 : deparseRelabelType((RelabelType *) node, context);
2314 60 : break;
2315 : case T_BoolExpr:
2316 72 : deparseBoolExpr((BoolExpr *) node, context);
2317 72 : break;
2318 : case T_NullTest:
2319 56 : deparseNullTest((NullTest *) node, context);
2320 56 : break;
2321 : case T_ArrayExpr:
2322 8 : deparseArrayExpr((ArrayExpr *) node, context);
2323 8 : break;
2324 : case T_Aggref:
2325 360 : deparseAggref((Aggref *) node, context);
2326 360 : break;
2327 : default:
2328 0 : elog(ERROR, "unsupported expression type for deparse: %d",
2329 : (int) nodeTag(node));
2330 : break;
2331 : }
2332 : }
2333 :
2334 : /*
2335 : * Deparse given Var node into context->buf.
2336 : *
2337 : * If the Var belongs to the foreign relation, just print its remote name.
2338 : * Otherwise, it's effectively a Param (and will in fact be a Param at
2339 : * run time). Handle it the same way we handle plain Params --- see
2340 : * deparseParam for comments.
2341 : */
2342 : static void
2343 8988 : deparseVar(Var *node, deparse_expr_cxt *context)
2344 : {
2345 8988 : Relids relids = context->scanrel->relids;
2346 : int relno;
2347 : int colno;
2348 :
2349 : /* Qualify columns when multiple relations are involved. */
2350 8988 : bool qualify_col = (bms_membership(relids) == BMS_MULTIPLE);
2351 :
2352 : /*
2353 : * If the Var belongs to the foreign relation that is deparsed as a
2354 : * subquery, use the relation and column alias to the Var provided by the
2355 : * subquery, instead of the remote name.
2356 : */
2357 8988 : if (is_subquery_var(node, context->scanrel, &relno, &colno))
2358 : {
2359 168 : appendStringInfo(context->buf, "%s%d.%s%d",
2360 : SUBQUERY_REL_ALIAS_PREFIX, relno,
2361 : SUBQUERY_COL_ALIAS_PREFIX, colno);
2362 168 : return;
2363 : }
2364 :
2365 8820 : if (bms_is_member(node->varno, relids) && node->varlevelsup == 0)
2366 25620 : deparseColumnRef(context->buf, node->varno, node->varattno,
2367 17080 : planner_rt_fetch(node->varno, context->root),
2368 : qualify_col);
2369 : else
2370 : {
2371 : /* Treat like a Param */
2372 280 : if (context->params_list)
2373 : {
2374 8 : int pindex = 0;
2375 : ListCell *lc;
2376 :
2377 : /* find its index in params_list */
2378 8 : foreach(lc, *context->params_list)
2379 : {
2380 0 : pindex++;
2381 0 : if (equal(node, (Node *) lfirst(lc)))
2382 0 : break;
2383 : }
2384 8 : if (lc == NULL)
2385 : {
2386 : /* not in list, so add it */
2387 8 : pindex++;
2388 8 : *context->params_list = lappend(*context->params_list, node);
2389 : }
2390 :
2391 8 : printRemoteParam(pindex, node->vartype, node->vartypmod, context);
2392 : }
2393 : else
2394 : {
2395 272 : printRemotePlaceholder(node->vartype, node->vartypmod, context);
2396 : }
2397 : }
2398 : }
2399 :
2400 : /*
2401 : * Deparse given constant value into context->buf.
2402 : *
2403 : * This function has to be kept in sync with ruleutils.c's get_const_expr.
2404 : * As for that function, showtype can be -1 to never show "::typename" decoration,
2405 : * or +1 to always show it, or 0 to show it only if the constant wouldn't be assumed
2406 : * to be the right type by default.
2407 : */
2408 : static void
2409 2182 : deparseConst(Const *node, deparse_expr_cxt *context, int showtype)
2410 : {
2411 2182 : StringInfo buf = context->buf;
2412 : Oid typoutput;
2413 : bool typIsVarlena;
2414 : char *extval;
2415 2182 : bool isfloat = false;
2416 : bool needlabel;
2417 :
2418 2182 : if (node->constisnull)
2419 : {
2420 14 : appendStringInfoString(buf, "NULL");
2421 14 : if (showtype >= 0)
2422 14 : appendStringInfo(buf, "::%s",
2423 : deparse_type_name(node->consttype,
2424 : node->consttypmod));
2425 28 : return;
2426 : }
2427 :
2428 2168 : getTypeOutputInfo(node->consttype,
2429 : &typoutput, &typIsVarlena);
2430 2168 : extval = OidOutputFunctionCall(typoutput, node->constvalue);
2431 :
2432 2168 : switch (node->consttype)
2433 : {
2434 : case INT2OID:
2435 : case INT4OID:
2436 : case INT8OID:
2437 : case OIDOID:
2438 : case FLOAT4OID:
2439 : case FLOAT8OID:
2440 : case NUMERICOID:
2441 : {
2442 : /*
2443 : * No need to quote unless it's a special value such as 'NaN'.
2444 : * See comments in get_const_expr().
2445 : */
2446 2048 : if (strspn(extval, "0123456789+-eE.") == strlen(extval))
2447 : {
2448 2048 : if (extval[0] == '+' || extval[0] == '-')
2449 2 : appendStringInfo(buf, "(%s)", extval);
2450 : else
2451 2046 : appendStringInfoString(buf, extval);
2452 2048 : if (strcspn(extval, "eE.") != strlen(extval))
2453 4 : isfloat = true; /* it looks like a float */
2454 : }
2455 : else
2456 0 : appendStringInfo(buf, "'%s'", extval);
2457 : }
2458 2048 : break;
2459 : case BITOID:
2460 : case VARBITOID:
2461 0 : appendStringInfo(buf, "B'%s'", extval);
2462 0 : break;
2463 : case BOOLOID:
2464 0 : if (strcmp(extval, "t") == 0)
2465 0 : appendStringInfoString(buf, "true");
2466 : else
2467 0 : appendStringInfoString(buf, "false");
2468 0 : break;
2469 : default:
2470 120 : deparseStringLiteral(buf, extval);
2471 120 : break;
2472 : }
2473 :
2474 2168 : pfree(extval);
2475 :
2476 2168 : if (showtype < 0)
2477 0 : return;
2478 :
2479 : /*
2480 : * For showtype == 0, append ::typename unless the constant will be
2481 : * implicitly typed as the right type when it is read in.
2482 : *
2483 : * XXX this code has to be kept in sync with the behavior of the parser,
2484 : * especially make_const.
2485 : */
2486 2168 : switch (node->consttype)
2487 : {
2488 : case BOOLOID:
2489 : case INT4OID:
2490 : case UNKNOWNOID:
2491 2004 : needlabel = false;
2492 2004 : break;
2493 : case NUMERICOID:
2494 40 : needlabel = !isfloat || (node->consttypmod >= 0);
2495 40 : break;
2496 : default:
2497 124 : needlabel = true;
2498 124 : break;
2499 : }
2500 2168 : if (needlabel || showtype > 0)
2501 160 : appendStringInfo(buf, "::%s",
2502 : deparse_type_name(node->consttype,
2503 : node->consttypmod));
2504 : }
2505 :
2506 : /*
2507 : * Deparse given Param node.
2508 : *
2509 : * If we're generating the query "for real", add the Param to
2510 : * context->params_list if it's not already present, and then use its index
2511 : * in that list as the remote parameter number. During EXPLAIN, there's
2512 : * no need to identify a parameter number.
2513 : */
2514 : static void
2515 40 : deparseParam(Param *node, deparse_expr_cxt *context)
2516 : {
2517 40 : if (context->params_list)
2518 : {
2519 26 : int pindex = 0;
2520 : ListCell *lc;
2521 :
2522 : /* find its index in params_list */
2523 30 : foreach(lc, *context->params_list)
2524 : {
2525 4 : pindex++;
2526 4 : if (equal(node, (Node *) lfirst(lc)))
2527 0 : break;
2528 : }
2529 26 : if (lc == NULL)
2530 : {
2531 : /* not in list, so add it */
2532 26 : pindex++;
2533 26 : *context->params_list = lappend(*context->params_list, node);
2534 : }
2535 :
2536 26 : printRemoteParam(pindex, node->paramtype, node->paramtypmod, context);
2537 : }
2538 : else
2539 : {
2540 14 : printRemotePlaceholder(node->paramtype, node->paramtypmod, context);
2541 : }
2542 40 : }
2543 :
2544 : /*
2545 : * Deparse an array subscript expression.
2546 : */
2547 : static void
2548 2 : deparseArrayRef(ArrayRef *node, deparse_expr_cxt *context)
2549 : {
2550 2 : StringInfo buf = context->buf;
2551 : ListCell *lowlist_item;
2552 : ListCell *uplist_item;
2553 :
2554 : /* Always parenthesize the expression. */
2555 2 : appendStringInfoChar(buf, '(');
2556 :
2557 : /*
2558 : * Deparse referenced array expression first. If that expression includes
2559 : * a cast, we have to parenthesize to prevent the array subscript from
2560 : * being taken as typename decoration. We can avoid that in the typical
2561 : * case of subscripting a Var, but otherwise do it.
2562 : */
2563 2 : if (IsA(node->refexpr, Var))
2564 0 : deparseExpr(node->refexpr, context);
2565 : else
2566 : {
2567 2 : appendStringInfoChar(buf, '(');
2568 2 : deparseExpr(node->refexpr, context);
2569 2 : appendStringInfoChar(buf, ')');
2570 : }
2571 :
2572 : /* Deparse subscript expressions. */
2573 2 : lowlist_item = list_head(node->reflowerindexpr); /* could be NULL */
2574 4 : foreach(uplist_item, node->refupperindexpr)
2575 : {
2576 2 : appendStringInfoChar(buf, '[');
2577 2 : if (lowlist_item)
2578 : {
2579 0 : deparseExpr(lfirst(lowlist_item), context);
2580 0 : appendStringInfoChar(buf, ':');
2581 0 : lowlist_item = lnext(lowlist_item);
2582 : }
2583 2 : deparseExpr(lfirst(uplist_item), context);
2584 2 : appendStringInfoChar(buf, ']');
2585 : }
2586 :
2587 2 : appendStringInfoChar(buf, ')');
2588 2 : }
2589 :
2590 : /*
2591 : * Deparse a function call.
2592 : */
2593 : static void
2594 96 : deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context)
2595 : {
2596 96 : StringInfo buf = context->buf;
2597 : bool use_variadic;
2598 : bool first;
2599 : ListCell *arg;
2600 :
2601 : /*
2602 : * If the function call came from an implicit coercion, then just show the
2603 : * first argument.
2604 : */
2605 96 : if (node->funcformat == COERCE_IMPLICIT_CAST)
2606 : {
2607 44 : deparseExpr((Expr *) linitial(node->args), context);
2608 44 : return;
2609 : }
2610 :
2611 : /*
2612 : * If the function call came from a cast, then show the first argument
2613 : * plus an explicit cast operation.
2614 : */
2615 52 : if (node->funcformat == COERCE_EXPLICIT_CAST)
2616 : {
2617 0 : Oid rettype = node->funcresulttype;
2618 : int32 coercedTypmod;
2619 :
2620 : /* Get the typmod if this is a length-coercion function */
2621 0 : (void) exprIsLengthCoercion((Node *) node, &coercedTypmod);
2622 :
2623 0 : deparseExpr((Expr *) linitial(node->args), context);
2624 0 : appendStringInfo(buf, "::%s",
2625 : deparse_type_name(rettype, coercedTypmod));
2626 0 : return;
2627 : }
2628 :
2629 : /* Check if need to print VARIADIC (cf. ruleutils.c) */
2630 52 : use_variadic = node->funcvariadic;
2631 :
2632 : /*
2633 : * Normal function: display as proname(args).
2634 : */
2635 52 : appendFunctionName(node->funcid, context);
2636 52 : appendStringInfoChar(buf, '(');
2637 :
2638 : /* ... and all the arguments */
2639 52 : first = true;
2640 106 : foreach(arg, node->args)
2641 : {
2642 54 : if (!first)
2643 2 : appendStringInfoString(buf, ", ");
2644 54 : if (use_variadic && lnext(arg) == NULL)
2645 0 : appendStringInfoString(buf, "VARIADIC ");
2646 54 : deparseExpr((Expr *) lfirst(arg), context);
2647 54 : first = false;
2648 : }
2649 52 : appendStringInfoChar(buf, ')');
2650 : }
2651 :
2652 : /*
2653 : * Deparse given operator expression. To avoid problems around
2654 : * priority of operations, we always parenthesize the arguments.
2655 : */
2656 : static void
2657 3382 : deparseOpExpr(OpExpr *node, deparse_expr_cxt *context)
2658 : {
2659 3382 : StringInfo buf = context->buf;
2660 : HeapTuple tuple;
2661 : Form_pg_operator form;
2662 : char oprkind;
2663 : ListCell *arg;
2664 :
2665 : /* Retrieve information about the operator from system catalog. */
2666 3382 : tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(node->opno));
2667 3382 : if (!HeapTupleIsValid(tuple))
2668 0 : elog(ERROR, "cache lookup failed for operator %u", node->opno);
2669 3382 : form = (Form_pg_operator) GETSTRUCT(tuple);
2670 3382 : oprkind = form->oprkind;
2671 :
2672 : /* Sanity check. */
2673 : Assert((oprkind == 'r' && list_length(node->args) == 1) ||
2674 : (oprkind == 'l' && list_length(node->args) == 1) ||
2675 : (oprkind == 'b' && list_length(node->args) == 2));
2676 :
2677 : /* Always parenthesize the expression. */
2678 3382 : appendStringInfoChar(buf, '(');
2679 :
2680 : /* Deparse left operand. */
2681 3382 : if (oprkind == 'r' || oprkind == 'b')
2682 : {
2683 3376 : arg = list_head(node->args);
2684 3376 : deparseExpr(lfirst(arg), context);
2685 3376 : appendStringInfoChar(buf, ' ');
2686 : }
2687 :
2688 : /* Deparse operator name. */
2689 3382 : deparseOperatorName(buf, form);
2690 :
2691 : /* Deparse right operand. */
2692 3382 : if (oprkind == 'l' || oprkind == 'b')
2693 : {
2694 3380 : arg = list_tail(node->args);
2695 3380 : appendStringInfoChar(buf, ' ');
2696 3380 : deparseExpr(lfirst(arg), context);
2697 : }
2698 :
2699 3382 : appendStringInfoChar(buf, ')');
2700 :
2701 3382 : ReleaseSysCache(tuple);
2702 3382 : }
2703 :
2704 : /*
2705 : * Print the name of an operator.
2706 : */
2707 : static void
2708 3398 : deparseOperatorName(StringInfo buf, Form_pg_operator opform)
2709 : {
2710 : char *opname;
2711 :
2712 : /* opname is not a SQL identifier, so we should not quote it. */
2713 3398 : opname = NameStr(opform->oprname);
2714 :
2715 : /* Print schema name only if it's not pg_catalog */
2716 3398 : if (opform->oprnamespace != PG_CATALOG_NAMESPACE)
2717 : {
2718 : const char *opnspname;
2719 :
2720 14 : opnspname = get_namespace_name(opform->oprnamespace);
2721 : /* Print fully qualified operator name. */
2722 14 : appendStringInfo(buf, "OPERATOR(%s.%s)",
2723 : quote_identifier(opnspname), opname);
2724 : }
2725 : else
2726 : {
2727 : /* Just print operator name. */
2728 3384 : appendStringInfoString(buf, opname);
2729 : }
2730 3398 : }
2731 :
2732 : /*
2733 : * Deparse IS DISTINCT FROM.
2734 : */
2735 : static void
2736 2 : deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context)
2737 : {
2738 2 : StringInfo buf = context->buf;
2739 :
2740 : Assert(list_length(node->args) == 2);
2741 :
2742 2 : appendStringInfoChar(buf, '(');
2743 2 : deparseExpr(linitial(node->args), context);
2744 2 : appendStringInfoString(buf, " IS DISTINCT FROM ");
2745 2 : deparseExpr(lsecond(node->args), context);
2746 2 : appendStringInfoChar(buf, ')');
2747 2 : }
2748 :
2749 : /*
2750 : * Deparse given ScalarArrayOpExpr expression. To avoid problems
2751 : * around priority of operations, we always parenthesize the arguments.
2752 : */
2753 : static void
2754 8 : deparseScalarArrayOpExpr(ScalarArrayOpExpr *node, deparse_expr_cxt *context)
2755 : {
2756 8 : StringInfo buf = context->buf;
2757 : HeapTuple tuple;
2758 : Form_pg_operator form;
2759 : Expr *arg1;
2760 : Expr *arg2;
2761 :
2762 : /* Retrieve information about the operator from system catalog. */
2763 8 : tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(node->opno));
2764 8 : if (!HeapTupleIsValid(tuple))
2765 0 : elog(ERROR, "cache lookup failed for operator %u", node->opno);
2766 8 : form = (Form_pg_operator) GETSTRUCT(tuple);
2767 :
2768 : /* Sanity check. */
2769 : Assert(list_length(node->args) == 2);
2770 :
2771 : /* Always parenthesize the expression. */
2772 8 : appendStringInfoChar(buf, '(');
2773 :
2774 : /* Deparse left operand. */
2775 8 : arg1 = linitial(node->args);
2776 8 : deparseExpr(arg1, context);
2777 8 : appendStringInfoChar(buf, ' ');
2778 :
2779 : /* Deparse operator name plus decoration. */
2780 8 : deparseOperatorName(buf, form);
2781 8 : appendStringInfo(buf, " %s (", node->useOr ? "ANY" : "ALL");
2782 :
2783 : /* Deparse right operand. */
2784 8 : arg2 = lsecond(node->args);
2785 8 : deparseExpr(arg2, context);
2786 :
2787 8 : appendStringInfoChar(buf, ')');
2788 :
2789 : /* Always parenthesize the expression. */
2790 8 : appendStringInfoChar(buf, ')');
2791 :
2792 8 : ReleaseSysCache(tuple);
2793 8 : }
2794 :
2795 : /*
2796 : * Deparse a RelabelType (binary-compatible cast) node.
2797 : */
2798 : static void
2799 60 : deparseRelabelType(RelabelType *node, deparse_expr_cxt *context)
2800 : {
2801 60 : deparseExpr(node->arg, context);
2802 60 : if (node->relabelformat != COERCE_IMPLICIT_CAST)
2803 0 : appendStringInfo(context->buf, "::%s",
2804 : deparse_type_name(node->resulttype,
2805 : node->resulttypmod));
2806 60 : }
2807 :
2808 : /*
2809 : * Deparse a BoolExpr node.
2810 : */
2811 : static void
2812 72 : deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context)
2813 : {
2814 72 : StringInfo buf = context->buf;
2815 72 : const char *op = NULL; /* keep compiler quiet */
2816 : bool first;
2817 : ListCell *lc;
2818 :
2819 72 : switch (node->boolop)
2820 : {
2821 : case AND_EXPR:
2822 32 : op = "AND";
2823 32 : break;
2824 : case OR_EXPR:
2825 40 : op = "OR";
2826 40 : break;
2827 : case NOT_EXPR:
2828 0 : appendStringInfoString(buf, "(NOT ");
2829 0 : deparseExpr(linitial(node->args), context);
2830 0 : appendStringInfoChar(buf, ')');
2831 0 : return;
2832 : }
2833 :
2834 72 : appendStringInfoChar(buf, '(');
2835 72 : first = true;
2836 216 : foreach(lc, node->args)
2837 : {
2838 144 : if (!first)
2839 72 : appendStringInfo(buf, " %s ", op);
2840 144 : deparseExpr((Expr *) lfirst(lc), context);
2841 144 : first = false;
2842 : }
2843 72 : appendStringInfoChar(buf, ')');
2844 : }
2845 :
2846 : /*
2847 : * Deparse IS [NOT] NULL expression.
2848 : */
2849 : static void
2850 56 : deparseNullTest(NullTest *node, deparse_expr_cxt *context)
2851 : {
2852 56 : StringInfo buf = context->buf;
2853 :
2854 56 : appendStringInfoChar(buf, '(');
2855 56 : deparseExpr(node->arg, context);
2856 :
2857 : /*
2858 : * For scalar inputs, we prefer to print as IS [NOT] NULL, which is
2859 : * shorter and traditional. If it's a rowtype input but we're applying a
2860 : * scalar test, must print IS [NOT] DISTINCT FROM NULL to be semantically
2861 : * correct.
2862 : */
2863 56 : if (node->argisrow || !type_is_rowtype(exprType((Node *) node->arg)))
2864 : {
2865 112 : if (node->nulltesttype == IS_NULL)
2866 38 : appendStringInfoString(buf, " IS NULL)");
2867 : else
2868 18 : appendStringInfoString(buf, " IS NOT NULL)");
2869 : }
2870 : else
2871 : {
2872 0 : if (node->nulltesttype == IS_NULL)
2873 0 : appendStringInfoString(buf, " IS NOT DISTINCT FROM NULL)");
2874 : else
2875 0 : appendStringInfoString(buf, " IS DISTINCT FROM NULL)");
2876 : }
2877 56 : }
2878 :
2879 : /*
2880 : * Deparse ARRAY[...] construct.
2881 : */
2882 : static void
2883 8 : deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context)
2884 : {
2885 8 : StringInfo buf = context->buf;
2886 8 : bool first = true;
2887 : ListCell *lc;
2888 :
2889 8 : appendStringInfoString(buf, "ARRAY[");
2890 24 : foreach(lc, node->elements)
2891 : {
2892 16 : if (!first)
2893 8 : appendStringInfoString(buf, ", ");
2894 16 : deparseExpr(lfirst(lc), context);
2895 16 : first = false;
2896 : }
2897 8 : appendStringInfoChar(buf, ']');
2898 :
2899 : /* If the array is empty, we need an explicit cast to the array type. */
2900 8 : if (node->elements == NIL)
2901 0 : appendStringInfo(buf, "::%s",
2902 : deparse_type_name(node->array_typeid, -1));
2903 8 : }
2904 :
2905 : /*
2906 : * Deparse an Aggref node.
2907 : */
2908 : static void
2909 360 : deparseAggref(Aggref *node, deparse_expr_cxt *context)
2910 : {
2911 360 : StringInfo buf = context->buf;
2912 : bool use_variadic;
2913 :
2914 : /* Only basic, non-split aggregation accepted. */
2915 : Assert(node->aggsplit == AGGSPLIT_SIMPLE);
2916 :
2917 : /* Check if need to print VARIADIC (cf. ruleutils.c) */
2918 360 : use_variadic = node->aggvariadic;
2919 :
2920 : /* Find aggregate name from aggfnoid which is a pg_proc entry */
2921 360 : appendFunctionName(node->aggfnoid, context);
2922 360 : appendStringInfoChar(buf, '(');
2923 :
2924 : /* Add DISTINCT */
2925 360 : appendStringInfoString(buf, (node->aggdistinct != NIL) ? "DISTINCT " : "");
2926 :
2927 360 : if (AGGKIND_IS_ORDERED_SET(node->aggkind))
2928 : {
2929 : /* Add WITHIN GROUP (ORDER BY ..) */
2930 : ListCell *arg;
2931 16 : bool first = true;
2932 :
2933 : Assert(!node->aggvariadic);
2934 : Assert(node->aggorder != NIL);
2935 :
2936 36 : foreach(arg, node->aggdirectargs)
2937 : {
2938 20 : if (!first)
2939 4 : appendStringInfoString(buf, ", ");
2940 20 : first = false;
2941 :
2942 20 : deparseExpr((Expr *) lfirst(arg), context);
2943 : }
2944 :
2945 16 : appendStringInfoString(buf, ") WITHIN GROUP (ORDER BY ");
2946 16 : appendAggOrderBy(node->aggorder, node->args, context);
2947 : }
2948 : else
2949 : {
2950 : /* aggstar can be set only in zero-argument aggregates */
2951 344 : if (node->aggstar)
2952 78 : appendStringInfoChar(buf, '*');
2953 : else
2954 : {
2955 : ListCell *arg;
2956 266 : bool first = true;
2957 :
2958 : /* Add all the arguments */
2959 540 : foreach(arg, node->args)
2960 : {
2961 274 : TargetEntry *tle = (TargetEntry *) lfirst(arg);
2962 274 : Node *n = (Node *) tle->expr;
2963 :
2964 274 : if (tle->resjunk)
2965 8 : continue;
2966 :
2967 266 : if (!first)
2968 0 : appendStringInfoString(buf, ", ");
2969 266 : first = false;
2970 :
2971 : /* Add VARIADIC */
2972 266 : if (use_variadic && lnext(arg) == NULL)
2973 4 : appendStringInfoString(buf, "VARIADIC ");
2974 :
2975 266 : deparseExpr((Expr *) n, context);
2976 : }
2977 : }
2978 :
2979 : /* Add ORDER BY */
2980 344 : if (node->aggorder != NIL)
2981 : {
2982 32 : appendStringInfoString(buf, " ORDER BY ");
2983 32 : appendAggOrderBy(node->aggorder, node->args, context);
2984 : }
2985 : }
2986 :
2987 : /* Add FILTER (WHERE ..) */
2988 360 : if (node->aggfilter != NULL)
2989 : {
2990 20 : appendStringInfoString(buf, ") FILTER (WHERE ");
2991 20 : deparseExpr((Expr *) node->aggfilter, context);
2992 : }
2993 :
2994 360 : appendStringInfoChar(buf, ')');
2995 360 : }
2996 :
2997 : /*
2998 : * Append ORDER BY within aggregate function.
2999 : */
3000 : static void
3001 48 : appendAggOrderBy(List *orderList, List *targetList, deparse_expr_cxt *context)
3002 : {
3003 48 : StringInfo buf = context->buf;
3004 : ListCell *lc;
3005 48 : bool first = true;
3006 :
3007 100 : foreach(lc, orderList)
3008 : {
3009 52 : SortGroupClause *srt = (SortGroupClause *) lfirst(lc);
3010 : Node *sortexpr;
3011 : Oid sortcoltype;
3012 : TypeCacheEntry *typentry;
3013 :
3014 52 : if (!first)
3015 4 : appendStringInfoString(buf, ", ");
3016 52 : first = false;
3017 :
3018 52 : sortexpr = deparseSortGroupClause(srt->tleSortGroupRef, targetList,
3019 : false, context);
3020 52 : sortcoltype = exprType(sortexpr);
3021 : /* See whether operator is default < or > for datatype */
3022 52 : typentry = lookup_type_cache(sortcoltype,
3023 : TYPECACHE_LT_OPR | TYPECACHE_GT_OPR);
3024 52 : if (srt->sortop == typentry->lt_opr)
3025 32 : appendStringInfoString(buf, " ASC");
3026 20 : else if (srt->sortop == typentry->gt_opr)
3027 12 : appendStringInfoString(buf, " DESC");
3028 : else
3029 : {
3030 : HeapTuple opertup;
3031 : Form_pg_operator operform;
3032 :
3033 8 : appendStringInfoString(buf, " USING ");
3034 :
3035 : /* Append operator name. */
3036 8 : opertup = SearchSysCache1(OPEROID, ObjectIdGetDatum(srt->sortop));
3037 8 : if (!HeapTupleIsValid(opertup))
3038 0 : elog(ERROR, "cache lookup failed for operator %u", srt->sortop);
3039 8 : operform = (Form_pg_operator) GETSTRUCT(opertup);
3040 8 : deparseOperatorName(buf, operform);
3041 8 : ReleaseSysCache(opertup);
3042 : }
3043 :
3044 52 : if (srt->nulls_first)
3045 8 : appendStringInfoString(buf, " NULLS FIRST");
3046 : else
3047 44 : appendStringInfoString(buf, " NULLS LAST");
3048 : }
3049 48 : }
3050 :
3051 : /*
3052 : * Print the representation of a parameter to be sent to the remote side.
3053 : *
3054 : * Note: we always label the Param's type explicitly rather than relying on
3055 : * transmitting a numeric type OID in PQexecParams(). This allows us to
3056 : * avoid assuming that types have the same OIDs on the remote side as they
3057 : * do locally --- they need only have the same names.
3058 : */
3059 : static void
3060 34 : printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod,
3061 : deparse_expr_cxt *context)
3062 : {
3063 34 : StringInfo buf = context->buf;
3064 34 : char *ptypename = deparse_type_name(paramtype, paramtypmod);
3065 :
3066 34 : appendStringInfo(buf, "$%d::%s", paramindex, ptypename);
3067 34 : }
3068 :
3069 : /*
3070 : * Print the representation of a placeholder for a parameter that will be
3071 : * sent to the remote side at execution time.
3072 : *
3073 : * This is used when we're just trying to EXPLAIN the remote query.
3074 : * We don't have the actual value of the runtime parameter yet, and we don't
3075 : * want the remote planner to generate a plan that depends on such a value
3076 : * anyway. Thus, we can't do something simple like "$1::paramtype".
3077 : * Instead, we emit "((SELECT null::paramtype)::paramtype)".
3078 : * In all extant versions of Postgres, the planner will see that as an unknown
3079 : * constant value, which is what we want. This might need adjustment if we
3080 : * ever make the planner flatten scalar subqueries. Note: the reason for the
3081 : * apparently useless outer cast is to ensure that the representation as a
3082 : * whole will be parsed as an a_expr and not a select_with_parens; the latter
3083 : * would do the wrong thing in the context "x = ANY(...)".
3084 : */
3085 : static void
3086 286 : printRemotePlaceholder(Oid paramtype, int32 paramtypmod,
3087 : deparse_expr_cxt *context)
3088 : {
3089 286 : StringInfo buf = context->buf;
3090 286 : char *ptypename = deparse_type_name(paramtype, paramtypmod);
3091 :
3092 286 : appendStringInfo(buf, "((SELECT null::%s)::%s)", ptypename, ptypename);
3093 286 : }
3094 :
3095 : /*
3096 : * Deparse GROUP BY clause.
3097 : */
3098 : static void
3099 246 : appendGroupByClause(List *tlist, deparse_expr_cxt *context)
3100 : {
3101 246 : StringInfo buf = context->buf;
3102 246 : Query *query = context->root->parse;
3103 : ListCell *lc;
3104 246 : bool first = true;
3105 :
3106 : /* Nothing to be done, if there's no GROUP BY clause in the query. */
3107 246 : if (!query->groupClause)
3108 72 : return;
3109 :
3110 174 : appendStringInfoString(buf, " GROUP BY ");
3111 :
3112 : /*
3113 : * Queries with grouping sets are not pushed down, so we don't expect
3114 : * grouping sets here.
3115 : */
3116 : Assert(!query->groupingSets);
3117 :
3118 372 : foreach(lc, query->groupClause)
3119 : {
3120 198 : SortGroupClause *grp = (SortGroupClause *) lfirst(lc);
3121 :
3122 198 : if (!first)
3123 24 : appendStringInfoString(buf, ", ");
3124 198 : first = false;
3125 :
3126 198 : deparseSortGroupClause(grp->tleSortGroupRef, tlist, true, context);
3127 : }
3128 : }
3129 :
3130 : /*
3131 : * Deparse ORDER BY clause according to the given pathkeys for given base
3132 : * relation. From given pathkeys expressions belonging entirely to the given
3133 : * base relation are obtained and deparsed.
3134 : */
3135 : static void
3136 776 : appendOrderByClause(List *pathkeys, deparse_expr_cxt *context)
3137 : {
3138 : ListCell *lcell;
3139 : int nestlevel;
3140 776 : char *delim = " ";
3141 776 : RelOptInfo *baserel = context->scanrel;
3142 776 : StringInfo buf = context->buf;
3143 :
3144 : /* Make sure any constants in the exprs are printed portably */
3145 776 : nestlevel = set_transmission_modes();
3146 :
3147 776 : appendStringInfoString(buf, " ORDER BY");
3148 1746 : foreach(lcell, pathkeys)
3149 : {
3150 970 : PathKey *pathkey = lfirst(lcell);
3151 : Expr *em_expr;
3152 :
3153 970 : em_expr = find_em_expr_for_rel(pathkey->pk_eclass, baserel);
3154 : Assert(em_expr != NULL);
3155 :
3156 970 : appendStringInfoString(buf, delim);
3157 970 : deparseExpr(em_expr, context);
3158 970 : if (pathkey->pk_strategy == BTLessStrategyNumber)
3159 960 : appendStringInfoString(buf, " ASC");
3160 : else
3161 10 : appendStringInfoString(buf, " DESC");
3162 :
3163 970 : if (pathkey->pk_nulls_first)
3164 10 : appendStringInfoString(buf, " NULLS FIRST");
3165 : else
3166 960 : appendStringInfoString(buf, " NULLS LAST");
3167 :
3168 970 : delim = ", ";
3169 : }
3170 776 : reset_transmission_modes(nestlevel);
3171 776 : }
3172 :
3173 : /*
3174 : * appendFunctionName
3175 : * Deparses function name from given function oid.
3176 : */
3177 : static void
3178 412 : appendFunctionName(Oid funcid, deparse_expr_cxt *context)
3179 : {
3180 412 : StringInfo buf = context->buf;
3181 : HeapTuple proctup;
3182 : Form_pg_proc procform;
3183 : const char *proname;
3184 :
3185 412 : proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
3186 412 : if (!HeapTupleIsValid(proctup))
3187 0 : elog(ERROR, "cache lookup failed for function %u", funcid);
3188 412 : procform = (Form_pg_proc) GETSTRUCT(proctup);
3189 :
3190 : /* Print schema name only if it's not pg_catalog */
3191 412 : if (procform->pronamespace != PG_CATALOG_NAMESPACE)
3192 : {
3193 : const char *schemaname;
3194 :
3195 12 : schemaname = get_namespace_name(procform->pronamespace);
3196 12 : appendStringInfo(buf, "%s.", quote_identifier(schemaname));
3197 : }
3198 :
3199 : /* Always print the function name */
3200 412 : proname = NameStr(procform->proname);
3201 412 : appendStringInfoString(buf, quote_identifier(proname));
3202 :
3203 412 : ReleaseSysCache(proctup);
3204 412 : }
3205 :
3206 : /*
3207 : * Appends a sort or group clause.
3208 : *
3209 : * Like get_rule_sortgroupclause(), returns the expression tree, so caller
3210 : * need not find it again.
3211 : */
3212 : static Node *
3213 250 : deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
3214 : deparse_expr_cxt *context)
3215 : {
3216 250 : StringInfo buf = context->buf;
3217 : TargetEntry *tle;
3218 : Expr *expr;
3219 :
3220 250 : tle = get_sortgroupref_tle(ref, tlist);
3221 250 : expr = tle->expr;
3222 :
3223 250 : if (force_colno)
3224 : {
3225 : /* Use column-number form when requested by caller. */
3226 : Assert(!tle->resjunk);
3227 198 : appendStringInfo(buf, "%d", tle->resno);
3228 : }
3229 52 : else if (expr && IsA(expr, Const))
3230 : {
3231 : /*
3232 : * Force a typecast here so that we don't emit something like "GROUP
3233 : * BY 2", which will be misconstrued as a column position rather than
3234 : * a constant.
3235 : */
3236 0 : deparseConst((Const *) expr, context, 1);
3237 : }
3238 52 : else if (!expr || IsA(expr, Var))
3239 32 : deparseExpr(expr, context);
3240 : else
3241 : {
3242 : /* Always parenthesize the expression. */
3243 20 : appendStringInfoChar(buf, '(');
3244 20 : deparseExpr(expr, context);
3245 20 : appendStringInfoChar(buf, ')');
3246 : }
3247 :
3248 250 : return (Node *) expr;
3249 : }
3250 :
3251 :
3252 : /*
3253 : * Returns true if given Var is deparsed as a subquery output column, in
3254 : * which case, *relno and *colno are set to the IDs for the relation and
3255 : * column alias to the Var provided by the subquery.
3256 : */
3257 : static bool
3258 8988 : is_subquery_var(Var *node, RelOptInfo *foreignrel, int *relno, int *colno)
3259 : {
3260 8988 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
3261 8988 : RelOptInfo *outerrel = fpinfo->outerrel;
3262 8988 : RelOptInfo *innerrel = fpinfo->innerrel;
3263 :
3264 : /* Should only be called in these cases. */
3265 : Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
3266 :
3267 : /*
3268 : * If the given relation isn't a join relation, it doesn't have any lower
3269 : * subqueries, so the Var isn't a subquery output column.
3270 : */
3271 8988 : if (!IS_JOIN_REL(foreignrel))
3272 2902 : return false;
3273 :
3274 : /*
3275 : * If the Var doesn't belong to any lower subqueries, it isn't a subquery
3276 : * output column.
3277 : */
3278 6086 : if (!bms_is_member(node->varno, fpinfo->lower_subquery_rels))
3279 5918 : return false;
3280 :
3281 168 : if (bms_is_member(node->varno, outerrel->relids))
3282 : {
3283 : /*
3284 : * If outer relation is deparsed as a subquery, the Var is an output
3285 : * column of the subquery; get the IDs for the relation/column alias.
3286 : */
3287 84 : if (fpinfo->make_outerrel_subquery)
3288 : {
3289 84 : get_relation_column_alias_ids(node, outerrel, relno, colno);
3290 84 : return true;
3291 : }
3292 :
3293 : /* Otherwise, recurse into the outer relation. */
3294 0 : return is_subquery_var(node, outerrel, relno, colno);
3295 : }
3296 : else
3297 : {
3298 : Assert(bms_is_member(node->varno, innerrel->relids));
3299 :
3300 : /*
3301 : * If inner relation is deparsed as a subquery, the Var is an output
3302 : * column of the subquery; get the IDs for the relation/column alias.
3303 : */
3304 84 : if (fpinfo->make_innerrel_subquery)
3305 : {
3306 84 : get_relation_column_alias_ids(node, innerrel, relno, colno);
3307 84 : return true;
3308 : }
3309 :
3310 : /* Otherwise, recurse into the inner relation. */
3311 0 : return is_subquery_var(node, innerrel, relno, colno);
3312 : }
3313 : }
3314 :
3315 : /*
3316 : * Get the IDs for the relation and column alias to given Var belonging to
3317 : * given relation, which are returned into *relno and *colno.
3318 : */
3319 : static void
3320 168 : get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel,
3321 : int *relno, int *colno)
3322 : {
3323 168 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
3324 : int i;
3325 : ListCell *lc;
3326 :
3327 : /* Get the relation alias ID */
3328 168 : *relno = fpinfo->relation_index;
3329 :
3330 : /* Get the column alias ID */
3331 168 : i = 1;
3332 192 : foreach(lc, foreignrel->reltarget->exprs)
3333 : {
3334 192 : if (equal(lfirst(lc), (Node *) node))
3335 : {
3336 168 : *colno = i;
3337 168 : return;
3338 : }
3339 24 : i++;
3340 : }
3341 :
3342 : /* Shouldn't get here */
3343 0 : elog(ERROR, "unexpected expression in subquery output");
3344 : }
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