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) 2012-2024, PostgreSQL Global Development Group
28 : *
29 : * IDENTIFICATION
30 : * contrib/postgres_fdw/deparse.c
31 : *
32 : *-------------------------------------------------------------------------
33 : */
34 : #include "postgres.h"
35 :
36 : #include "access/htup_details.h"
37 : #include "access/sysattr.h"
38 : #include "access/table.h"
39 : #include "catalog/pg_aggregate.h"
40 : #include "catalog/pg_authid.h"
41 : #include "catalog/pg_collation.h"
42 : #include "catalog/pg_namespace.h"
43 : #include "catalog/pg_operator.h"
44 : #include "catalog/pg_opfamily.h"
45 : #include "catalog/pg_proc.h"
46 : #include "catalog/pg_ts_config.h"
47 : #include "catalog/pg_ts_dict.h"
48 : #include "catalog/pg_type.h"
49 : #include "commands/defrem.h"
50 : #include "nodes/nodeFuncs.h"
51 : #include "nodes/plannodes.h"
52 : #include "optimizer/optimizer.h"
53 : #include "optimizer/prep.h"
54 : #include "optimizer/tlist.h"
55 : #include "parser/parsetree.h"
56 : #include "postgres_fdw.h"
57 : #include "utils/builtins.h"
58 : #include "utils/lsyscache.h"
59 : #include "utils/rel.h"
60 : #include "utils/syscache.h"
61 : #include "utils/typcache.h"
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 : foreign_loc_cxt *case_arg_cxt);
123 : static char *deparse_type_name(Oid type_oid, int32 typemod);
124 :
125 : /*
126 : * Functions to construct string representation of a node tree.
127 : */
128 : static void deparseTargetList(StringInfo buf,
129 : RangeTblEntry *rte,
130 : Index rtindex,
131 : Relation rel,
132 : bool is_returning,
133 : Bitmapset *attrs_used,
134 : bool qualify_col,
135 : List **retrieved_attrs);
136 : static void deparseExplicitTargetList(List *tlist,
137 : bool is_returning,
138 : List **retrieved_attrs,
139 : deparse_expr_cxt *context);
140 : static void deparseSubqueryTargetList(deparse_expr_cxt *context);
141 : static void deparseReturningList(StringInfo buf, RangeTblEntry *rte,
142 : Index rtindex, Relation rel,
143 : bool trig_after_row,
144 : List *withCheckOptionList,
145 : List *returningList,
146 : List **retrieved_attrs);
147 : static void deparseColumnRef(StringInfo buf, int varno, int varattno,
148 : RangeTblEntry *rte, bool qualify_col);
149 : static void deparseRelation(StringInfo buf, Relation rel);
150 : static void deparseExpr(Expr *node, deparse_expr_cxt *context);
151 : static void deparseVar(Var *node, deparse_expr_cxt *context);
152 : static void deparseConst(Const *node, deparse_expr_cxt *context, int showtype);
153 : static void deparseParam(Param *node, deparse_expr_cxt *context);
154 : static void deparseSubscriptingRef(SubscriptingRef *node, deparse_expr_cxt *context);
155 : static void deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context);
156 : static void deparseOpExpr(OpExpr *node, deparse_expr_cxt *context);
157 : static bool isPlainForeignVar(Expr *node, deparse_expr_cxt *context);
158 : static void deparseOperatorName(StringInfo buf, Form_pg_operator opform);
159 : static void deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context);
160 : static void deparseScalarArrayOpExpr(ScalarArrayOpExpr *node,
161 : deparse_expr_cxt *context);
162 : static void deparseRelabelType(RelabelType *node, deparse_expr_cxt *context);
163 : static void deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context);
164 : static void deparseNullTest(NullTest *node, deparse_expr_cxt *context);
165 : static void deparseCaseExpr(CaseExpr *node, deparse_expr_cxt *context);
166 : static void deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context);
167 : static void printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod,
168 : deparse_expr_cxt *context);
169 : static void printRemotePlaceholder(Oid paramtype, int32 paramtypmod,
170 : deparse_expr_cxt *context);
171 : static void deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs,
172 : deparse_expr_cxt *context);
173 : static void deparseLockingClause(deparse_expr_cxt *context);
174 : static void appendOrderByClause(List *pathkeys, bool has_final_sort,
175 : deparse_expr_cxt *context);
176 : static void appendLimitClause(deparse_expr_cxt *context);
177 : static void appendConditions(List *exprs, deparse_expr_cxt *context);
178 : static void deparseFromExprForRel(StringInfo buf, PlannerInfo *root,
179 : RelOptInfo *foreignrel, bool use_alias,
180 : Index ignore_rel, List **ignore_conds,
181 : List **additional_conds,
182 : List **params_list);
183 : static void appendWhereClause(List *exprs, List *additional_conds,
184 : deparse_expr_cxt *context);
185 : static void deparseFromExpr(List *quals, deparse_expr_cxt *context);
186 : static void deparseRangeTblRef(StringInfo buf, PlannerInfo *root,
187 : RelOptInfo *foreignrel, bool make_subquery,
188 : Index ignore_rel, List **ignore_conds,
189 : List **additional_conds, List **params_list);
190 : static void deparseAggref(Aggref *node, deparse_expr_cxt *context);
191 : static void appendGroupByClause(List *tlist, deparse_expr_cxt *context);
192 : static void appendOrderBySuffix(Oid sortop, Oid sortcoltype, bool nulls_first,
193 : deparse_expr_cxt *context);
194 : static void appendAggOrderBy(List *orderList, List *targetList,
195 : deparse_expr_cxt *context);
196 : static void appendFunctionName(Oid funcid, deparse_expr_cxt *context);
197 : static Node *deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
198 : deparse_expr_cxt *context);
199 :
200 : /*
201 : * Helper functions
202 : */
203 : static bool is_subquery_var(Var *node, RelOptInfo *foreignrel,
204 : int *relno, int *colno);
205 : static void get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel,
206 : int *relno, int *colno);
207 :
208 :
209 : /*
210 : * Examine each qual clause in input_conds, and classify them into two groups,
211 : * which are returned as two lists:
212 : * - remote_conds contains expressions that can be evaluated remotely
213 : * - local_conds contains expressions that can't be evaluated remotely
214 : */
215 : void
216 4738 : classifyConditions(PlannerInfo *root,
217 : RelOptInfo *baserel,
218 : List *input_conds,
219 : List **remote_conds,
220 : List **local_conds)
221 : {
222 : ListCell *lc;
223 :
224 4738 : *remote_conds = NIL;
225 4738 : *local_conds = NIL;
226 :
227 6176 : foreach(lc, input_conds)
228 : {
229 1438 : RestrictInfo *ri = lfirst_node(RestrictInfo, lc);
230 :
231 1438 : if (is_foreign_expr(root, baserel, ri->clause))
232 1272 : *remote_conds = lappend(*remote_conds, ri);
233 : else
234 166 : *local_conds = lappend(*local_conds, ri);
235 : }
236 4738 : }
237 :
238 : /*
239 : * Returns true if given expr is safe to evaluate on the foreign server.
240 : */
241 : bool
242 7294 : is_foreign_expr(PlannerInfo *root,
243 : RelOptInfo *baserel,
244 : Expr *expr)
245 : {
246 : foreign_glob_cxt glob_cxt;
247 : foreign_loc_cxt loc_cxt;
248 7294 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) (baserel->fdw_private);
249 :
250 : /*
251 : * Check that the expression consists of nodes that are safe to execute
252 : * remotely.
253 : */
254 7294 : glob_cxt.root = root;
255 7294 : glob_cxt.foreignrel = baserel;
256 :
257 : /*
258 : * For an upper relation, use relids from its underneath scan relation,
259 : * because the upperrel's own relids currently aren't set to anything
260 : * meaningful by the core code. For other relation, use their own relids.
261 : */
262 7294 : if (IS_UPPER_REL(baserel))
263 900 : glob_cxt.relids = fpinfo->outerrel->relids;
264 : else
265 6394 : glob_cxt.relids = baserel->relids;
266 7294 : loc_cxt.collation = InvalidOid;
267 7294 : loc_cxt.state = FDW_COLLATE_NONE;
268 7294 : if (!foreign_expr_walker((Node *) expr, &glob_cxt, &loc_cxt, NULL))
269 300 : return false;
270 :
271 : /*
272 : * If the expression has a valid collation that does not arise from a
273 : * foreign var, the expression can not be sent over.
274 : */
275 6994 : if (loc_cxt.state == FDW_COLLATE_UNSAFE)
276 4 : return false;
277 :
278 : /*
279 : * An expression which includes any mutable functions can't be sent over
280 : * because its result is not stable. For example, sending now() remote
281 : * side could cause confusion from clock offsets. Future versions might
282 : * be able to make this choice with more granularity. (We check this last
283 : * because it requires a lot of expensive catalog lookups.)
284 : */
285 6990 : if (contain_mutable_functions((Node *) expr))
286 48 : return false;
287 :
288 : /* OK to evaluate on the remote server */
289 6942 : return true;
290 : }
291 :
292 : /*
293 : * Check if expression is safe to execute remotely, and return true if so.
294 : *
295 : * In addition, *outer_cxt is updated with collation information.
296 : *
297 : * case_arg_cxt is NULL if this subexpression is not inside a CASE-with-arg.
298 : * Otherwise, it points to the collation info derived from the arg expression,
299 : * which must be consulted by any CaseTestExpr.
300 : *
301 : * We must check that the expression contains only node types we can deparse,
302 : * that all types/functions/operators are safe to send (they are "shippable"),
303 : * and that all collations used in the expression derive from Vars of the
304 : * foreign table. Because of the latter, the logic is pretty close to
305 : * assign_collations_walker() in parse_collate.c, though we can assume here
306 : * that the given expression is valid. Note function mutability is not
307 : * currently considered here.
308 : */
309 : static bool
310 18128 : foreign_expr_walker(Node *node,
311 : foreign_glob_cxt *glob_cxt,
312 : foreign_loc_cxt *outer_cxt,
313 : foreign_loc_cxt *case_arg_cxt)
314 : {
315 18128 : bool check_type = true;
316 : PgFdwRelationInfo *fpinfo;
317 : foreign_loc_cxt inner_cxt;
318 : Oid collation;
319 : FDWCollateState state;
320 :
321 : /* Need do nothing for empty subexpressions */
322 18128 : if (node == NULL)
323 650 : return true;
324 :
325 : /* May need server info from baserel's fdw_private struct */
326 17478 : fpinfo = (PgFdwRelationInfo *) (glob_cxt->foreignrel->fdw_private);
327 :
328 : /* Set up inner_cxt for possible recursion to child nodes */
329 17478 : inner_cxt.collation = InvalidOid;
330 17478 : inner_cxt.state = FDW_COLLATE_NONE;
331 :
332 17478 : switch (nodeTag(node))
333 : {
334 8060 : case T_Var:
335 : {
336 8060 : Var *var = (Var *) node;
337 :
338 : /*
339 : * If the Var is from the foreign table, we consider its
340 : * collation (if any) safe to use. If it is from another
341 : * table, we treat its collation the same way as we would a
342 : * Param's collation, ie it's not safe for it to have a
343 : * non-default collation.
344 : */
345 8060 : if (bms_is_member(var->varno, glob_cxt->relids) &&
346 7214 : var->varlevelsup == 0)
347 : {
348 : /* Var belongs to foreign table */
349 :
350 : /*
351 : * System columns other than ctid should not be sent to
352 : * the remote, since we don't make any effort to ensure
353 : * that local and remote values match (tableoid, in
354 : * particular, almost certainly doesn't match).
355 : */
356 7214 : if (var->varattno < 0 &&
357 20 : var->varattno != SelfItemPointerAttributeNumber)
358 16 : return false;
359 :
360 : /* Else check the collation */
361 7198 : collation = var->varcollid;
362 7198 : state = OidIsValid(collation) ? FDW_COLLATE_SAFE : FDW_COLLATE_NONE;
363 : }
364 : else
365 : {
366 : /* Var belongs to some other table */
367 846 : collation = var->varcollid;
368 846 : if (collation == InvalidOid ||
369 : collation == DEFAULT_COLLATION_OID)
370 : {
371 : /*
372 : * It's noncollatable, or it's safe to combine with a
373 : * collatable foreign Var, so set state to NONE.
374 : */
375 846 : state = FDW_COLLATE_NONE;
376 : }
377 : else
378 : {
379 : /*
380 : * Do not fail right away, since the Var might appear
381 : * in a collation-insensitive context.
382 : */
383 0 : state = FDW_COLLATE_UNSAFE;
384 : }
385 : }
386 : }
387 8044 : break;
388 1804 : case T_Const:
389 : {
390 1804 : Const *c = (Const *) node;
391 :
392 : /*
393 : * Constants of regproc and related types can't be shipped
394 : * unless the referenced object is shippable. But NULL's ok.
395 : * (See also the related code in dependency.c.)
396 : */
397 1804 : if (!c->constisnull)
398 : {
399 1786 : switch (c->consttype)
400 : {
401 0 : case REGPROCOID:
402 : case REGPROCEDUREOID:
403 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
404 : ProcedureRelationId, fpinfo))
405 0 : return false;
406 0 : break;
407 0 : case REGOPEROID:
408 : case REGOPERATOROID:
409 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
410 : OperatorRelationId, fpinfo))
411 0 : return false;
412 0 : break;
413 0 : case REGCLASSOID:
414 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
415 : RelationRelationId, fpinfo))
416 0 : return false;
417 0 : break;
418 0 : case REGTYPEOID:
419 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
420 : TypeRelationId, fpinfo))
421 0 : return false;
422 0 : break;
423 0 : case REGCOLLATIONOID:
424 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
425 : CollationRelationId, fpinfo))
426 0 : return false;
427 0 : break;
428 8 : case REGCONFIGOID:
429 :
430 : /*
431 : * For text search objects only, we weaken the
432 : * normal shippability criterion to allow all OIDs
433 : * below FirstNormalObjectId. Without this, none
434 : * of the initdb-installed TS configurations would
435 : * be shippable, which would be quite annoying.
436 : */
437 8 : if (DatumGetObjectId(c->constvalue) >= FirstNormalObjectId &&
438 8 : !is_shippable(DatumGetObjectId(c->constvalue),
439 : TSConfigRelationId, fpinfo))
440 4 : return false;
441 4 : break;
442 0 : case REGDICTIONARYOID:
443 0 : if (DatumGetObjectId(c->constvalue) >= FirstNormalObjectId &&
444 0 : !is_shippable(DatumGetObjectId(c->constvalue),
445 : TSDictionaryRelationId, fpinfo))
446 0 : return false;
447 0 : break;
448 0 : case REGNAMESPACEOID:
449 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
450 : NamespaceRelationId, fpinfo))
451 0 : return false;
452 0 : break;
453 0 : case REGROLEOID:
454 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
455 : AuthIdRelationId, fpinfo))
456 0 : return false;
457 0 : break;
458 : }
459 18 : }
460 :
461 : /*
462 : * If the constant has nondefault collation, either it's of a
463 : * non-builtin type, or it reflects folding of a CollateExpr.
464 : * It's unsafe to send to the remote unless it's used in a
465 : * non-collation-sensitive context.
466 : */
467 1800 : collation = c->constcollid;
468 1800 : if (collation == InvalidOid ||
469 : collation == DEFAULT_COLLATION_OID)
470 1796 : state = FDW_COLLATE_NONE;
471 : else
472 4 : state = FDW_COLLATE_UNSAFE;
473 : }
474 1800 : break;
475 50 : case T_Param:
476 : {
477 50 : Param *p = (Param *) node;
478 :
479 : /*
480 : * If it's a MULTIEXPR Param, punt. We can't tell from here
481 : * whether the referenced sublink/subplan contains any remote
482 : * Vars; if it does, handling that is too complicated to
483 : * consider supporting at present. Fortunately, MULTIEXPR
484 : * Params are not reduced to plain PARAM_EXEC until the end of
485 : * planning, so we can easily detect this case. (Normal
486 : * PARAM_EXEC Params are safe to ship because their values
487 : * come from somewhere else in the plan tree; but a MULTIEXPR
488 : * references a sub-select elsewhere in the same targetlist,
489 : * so we'd be on the hook to evaluate it somehow if we wanted
490 : * to handle such cases as direct foreign updates.)
491 : */
492 50 : if (p->paramkind == PARAM_MULTIEXPR)
493 6 : return false;
494 :
495 : /*
496 : * Collation rule is same as for Consts and non-foreign Vars.
497 : */
498 44 : collation = p->paramcollid;
499 44 : if (collation == InvalidOid ||
500 : collation == DEFAULT_COLLATION_OID)
501 44 : state = FDW_COLLATE_NONE;
502 : else
503 0 : state = FDW_COLLATE_UNSAFE;
504 : }
505 44 : break;
506 2 : case T_SubscriptingRef:
507 : {
508 2 : SubscriptingRef *sr = (SubscriptingRef *) node;
509 :
510 : /* Assignment should not be in restrictions. */
511 2 : if (sr->refassgnexpr != NULL)
512 0 : return false;
513 :
514 : /*
515 : * Recurse into the remaining subexpressions. The container
516 : * subscripts will not affect collation of the SubscriptingRef
517 : * result, so do those first and reset inner_cxt afterwards.
518 : */
519 2 : if (!foreign_expr_walker((Node *) sr->refupperindexpr,
520 : glob_cxt, &inner_cxt, case_arg_cxt))
521 0 : return false;
522 2 : inner_cxt.collation = InvalidOid;
523 2 : inner_cxt.state = FDW_COLLATE_NONE;
524 2 : if (!foreign_expr_walker((Node *) sr->reflowerindexpr,
525 : glob_cxt, &inner_cxt, case_arg_cxt))
526 0 : return false;
527 2 : inner_cxt.collation = InvalidOid;
528 2 : inner_cxt.state = FDW_COLLATE_NONE;
529 2 : if (!foreign_expr_walker((Node *) sr->refexpr,
530 : glob_cxt, &inner_cxt, case_arg_cxt))
531 0 : return false;
532 :
533 : /*
534 : * Container subscripting typically yields same collation as
535 : * refexpr's, but in case it doesn't, use same logic as for
536 : * function nodes.
537 : */
538 2 : collation = sr->refcollid;
539 2 : if (collation == InvalidOid)
540 2 : state = FDW_COLLATE_NONE;
541 0 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
542 0 : collation == inner_cxt.collation)
543 0 : state = FDW_COLLATE_SAFE;
544 0 : else if (collation == DEFAULT_COLLATION_OID)
545 0 : state = FDW_COLLATE_NONE;
546 : else
547 0 : state = FDW_COLLATE_UNSAFE;
548 : }
549 2 : break;
550 268 : case T_FuncExpr:
551 : {
552 268 : FuncExpr *fe = (FuncExpr *) node;
553 :
554 : /*
555 : * If function used by the expression is not shippable, it
556 : * can't be sent to remote because it might have incompatible
557 : * semantics on remote side.
558 : */
559 268 : if (!is_shippable(fe->funcid, ProcedureRelationId, fpinfo))
560 16 : return false;
561 :
562 : /*
563 : * Recurse to input subexpressions.
564 : */
565 252 : if (!foreign_expr_walker((Node *) fe->args,
566 : glob_cxt, &inner_cxt, case_arg_cxt))
567 26 : return false;
568 :
569 : /*
570 : * If function's input collation is not derived from a foreign
571 : * Var, it can't be sent to remote.
572 : */
573 226 : if (fe->inputcollid == InvalidOid)
574 : /* OK, inputs are all noncollatable */ ;
575 66 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
576 40 : fe->inputcollid != inner_cxt.collation)
577 26 : return false;
578 :
579 : /*
580 : * Detect whether node is introducing a collation not derived
581 : * from a foreign Var. (If so, we just mark it unsafe for now
582 : * rather than immediately returning false, since the parent
583 : * node might not care.)
584 : */
585 200 : collation = fe->funccollid;
586 200 : if (collation == InvalidOid)
587 162 : state = FDW_COLLATE_NONE;
588 38 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
589 36 : collation == inner_cxt.collation)
590 36 : state = FDW_COLLATE_SAFE;
591 2 : else if (collation == DEFAULT_COLLATION_OID)
592 0 : state = FDW_COLLATE_NONE;
593 : else
594 2 : state = FDW_COLLATE_UNSAFE;
595 : }
596 200 : break;
597 3056 : case T_OpExpr:
598 : case T_DistinctExpr: /* struct-equivalent to OpExpr */
599 : {
600 3056 : OpExpr *oe = (OpExpr *) node;
601 :
602 : /*
603 : * Similarly, only shippable operators can be sent to remote.
604 : * (If the operator is shippable, we assume its underlying
605 : * function is too.)
606 : */
607 3056 : if (!is_shippable(oe->opno, OperatorRelationId, fpinfo))
608 94 : return false;
609 :
610 : /*
611 : * Recurse to input subexpressions.
612 : */
613 2962 : if (!foreign_expr_walker((Node *) oe->args,
614 : glob_cxt, &inner_cxt, case_arg_cxt))
615 126 : return false;
616 :
617 : /*
618 : * If operator's input collation is not derived from a foreign
619 : * Var, it can't be sent to remote.
620 : */
621 2836 : if (oe->inputcollid == InvalidOid)
622 : /* OK, inputs are all noncollatable */ ;
623 138 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
624 126 : oe->inputcollid != inner_cxt.collation)
625 12 : return false;
626 :
627 : /* Result-collation handling is same as for functions */
628 2824 : collation = oe->opcollid;
629 2824 : if (collation == InvalidOid)
630 2796 : state = FDW_COLLATE_NONE;
631 28 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
632 28 : collation == inner_cxt.collation)
633 28 : state = FDW_COLLATE_SAFE;
634 0 : else if (collation == DEFAULT_COLLATION_OID)
635 0 : state = FDW_COLLATE_NONE;
636 : else
637 0 : state = FDW_COLLATE_UNSAFE;
638 : }
639 2824 : break;
640 6 : case T_ScalarArrayOpExpr:
641 : {
642 6 : ScalarArrayOpExpr *oe = (ScalarArrayOpExpr *) node;
643 :
644 : /*
645 : * Again, only shippable operators can be sent to remote.
646 : */
647 6 : if (!is_shippable(oe->opno, OperatorRelationId, fpinfo))
648 0 : return false;
649 :
650 : /*
651 : * Recurse to input subexpressions.
652 : */
653 6 : if (!foreign_expr_walker((Node *) oe->args,
654 : glob_cxt, &inner_cxt, case_arg_cxt))
655 0 : return false;
656 :
657 : /*
658 : * If operator's input collation is not derived from a foreign
659 : * Var, it can't be sent to remote.
660 : */
661 6 : if (oe->inputcollid == InvalidOid)
662 : /* OK, inputs are all noncollatable */ ;
663 0 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
664 0 : oe->inputcollid != inner_cxt.collation)
665 0 : return false;
666 :
667 : /* Output is always boolean and so noncollatable. */
668 6 : collation = InvalidOid;
669 6 : state = FDW_COLLATE_NONE;
670 : }
671 6 : break;
672 136 : case T_RelabelType:
673 : {
674 136 : RelabelType *r = (RelabelType *) node;
675 :
676 : /*
677 : * Recurse to input subexpression.
678 : */
679 136 : if (!foreign_expr_walker((Node *) r->arg,
680 : glob_cxt, &inner_cxt, case_arg_cxt))
681 0 : return false;
682 :
683 : /*
684 : * RelabelType must not introduce a collation not derived from
685 : * an input foreign Var (same logic as for a real function).
686 : */
687 136 : collation = r->resultcollid;
688 136 : if (collation == InvalidOid)
689 0 : state = FDW_COLLATE_NONE;
690 136 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
691 128 : collation == inner_cxt.collation)
692 116 : state = FDW_COLLATE_SAFE;
693 20 : else if (collation == DEFAULT_COLLATION_OID)
694 6 : state = FDW_COLLATE_NONE;
695 : else
696 14 : state = FDW_COLLATE_UNSAFE;
697 : }
698 136 : break;
699 72 : case T_BoolExpr:
700 : {
701 72 : BoolExpr *b = (BoolExpr *) node;
702 :
703 : /*
704 : * Recurse to input subexpressions.
705 : */
706 72 : if (!foreign_expr_walker((Node *) b->args,
707 : glob_cxt, &inner_cxt, case_arg_cxt))
708 0 : return false;
709 :
710 : /* Output is always boolean and so noncollatable. */
711 72 : collation = InvalidOid;
712 72 : state = FDW_COLLATE_NONE;
713 : }
714 72 : break;
715 54 : case T_NullTest:
716 : {
717 54 : NullTest *nt = (NullTest *) node;
718 :
719 : /*
720 : * Recurse to input subexpressions.
721 : */
722 54 : if (!foreign_expr_walker((Node *) nt->arg,
723 : glob_cxt, &inner_cxt, case_arg_cxt))
724 0 : return false;
725 :
726 : /* Output is always boolean and so noncollatable. */
727 54 : collation = InvalidOid;
728 54 : state = FDW_COLLATE_NONE;
729 : }
730 54 : break;
731 26 : case T_CaseExpr:
732 : {
733 26 : CaseExpr *ce = (CaseExpr *) node;
734 : foreign_loc_cxt arg_cxt;
735 : foreign_loc_cxt tmp_cxt;
736 : ListCell *lc;
737 :
738 : /*
739 : * Recurse to CASE's arg expression, if any. Its collation
740 : * has to be saved aside for use while examining CaseTestExprs
741 : * within the WHEN expressions.
742 : */
743 26 : arg_cxt.collation = InvalidOid;
744 26 : arg_cxt.state = FDW_COLLATE_NONE;
745 26 : if (ce->arg)
746 : {
747 14 : if (!foreign_expr_walker((Node *) ce->arg,
748 : glob_cxt, &arg_cxt, case_arg_cxt))
749 2 : return false;
750 : }
751 :
752 : /* Examine the CaseWhen subexpressions. */
753 58 : foreach(lc, ce->args)
754 : {
755 34 : CaseWhen *cw = lfirst_node(CaseWhen, lc);
756 :
757 34 : if (ce->arg)
758 : {
759 : /*
760 : * In a CASE-with-arg, the parser should have produced
761 : * WHEN clauses of the form "CaseTestExpr = RHS",
762 : * possibly with an implicit coercion inserted above
763 : * the CaseTestExpr. However in an expression that's
764 : * been through the optimizer, the WHEN clause could
765 : * be almost anything (since the equality operator
766 : * could have been expanded into an inline function).
767 : * In such cases forbid pushdown, because
768 : * deparseCaseExpr can't handle it.
769 : */
770 22 : Node *whenExpr = (Node *) cw->expr;
771 : List *opArgs;
772 :
773 22 : if (!IsA(whenExpr, OpExpr))
774 2 : return false;
775 :
776 22 : opArgs = ((OpExpr *) whenExpr)->args;
777 22 : if (list_length(opArgs) != 2 ||
778 22 : !IsA(strip_implicit_coercions(linitial(opArgs)),
779 : CaseTestExpr))
780 0 : return false;
781 : }
782 :
783 : /*
784 : * Recurse to WHEN expression, passing down the arg info.
785 : * Its collation doesn't affect the result (really, it
786 : * should be boolean and thus not have a collation).
787 : */
788 34 : tmp_cxt.collation = InvalidOid;
789 34 : tmp_cxt.state = FDW_COLLATE_NONE;
790 34 : if (!foreign_expr_walker((Node *) cw->expr,
791 : glob_cxt, &tmp_cxt, &arg_cxt))
792 2 : return false;
793 :
794 : /* Recurse to THEN expression. */
795 32 : if (!foreign_expr_walker((Node *) cw->result,
796 : glob_cxt, &inner_cxt, case_arg_cxt))
797 0 : return false;
798 : }
799 :
800 : /* Recurse to ELSE expression. */
801 24 : if (!foreign_expr_walker((Node *) ce->defresult,
802 : glob_cxt, &inner_cxt, case_arg_cxt))
803 0 : return false;
804 :
805 : /*
806 : * Detect whether node is introducing a collation not derived
807 : * from a foreign Var. (If so, we just mark it unsafe for now
808 : * rather than immediately returning false, since the parent
809 : * node might not care.) This is the same as for function
810 : * nodes, except that the input collation is derived from only
811 : * the THEN and ELSE subexpressions.
812 : */
813 24 : collation = ce->casecollid;
814 24 : if (collation == InvalidOid)
815 24 : state = FDW_COLLATE_NONE;
816 0 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
817 0 : collation == inner_cxt.collation)
818 0 : state = FDW_COLLATE_SAFE;
819 0 : else if (collation == DEFAULT_COLLATION_OID)
820 0 : state = FDW_COLLATE_NONE;
821 : else
822 0 : state = FDW_COLLATE_UNSAFE;
823 : }
824 24 : break;
825 22 : case T_CaseTestExpr:
826 : {
827 22 : CaseTestExpr *c = (CaseTestExpr *) node;
828 :
829 : /* Punt if we seem not to be inside a CASE arg WHEN. */
830 22 : if (!case_arg_cxt)
831 0 : return false;
832 :
833 : /*
834 : * Otherwise, any nondefault collation attached to the
835 : * CaseTestExpr node must be derived from foreign Var(s) in
836 : * the CASE arg.
837 : */
838 22 : collation = c->collation;
839 22 : if (collation == InvalidOid)
840 16 : state = FDW_COLLATE_NONE;
841 6 : else if (case_arg_cxt->state == FDW_COLLATE_SAFE &&
842 4 : collation == case_arg_cxt->collation)
843 4 : state = FDW_COLLATE_SAFE;
844 2 : else if (collation == DEFAULT_COLLATION_OID)
845 0 : state = FDW_COLLATE_NONE;
846 : else
847 2 : state = FDW_COLLATE_UNSAFE;
848 : }
849 22 : break;
850 8 : case T_ArrayExpr:
851 : {
852 8 : ArrayExpr *a = (ArrayExpr *) node;
853 :
854 : /*
855 : * Recurse to input subexpressions.
856 : */
857 8 : if (!foreign_expr_walker((Node *) a->elements,
858 : glob_cxt, &inner_cxt, case_arg_cxt))
859 0 : return false;
860 :
861 : /*
862 : * ArrayExpr must not introduce a collation not derived from
863 : * an input foreign Var (same logic as for a function).
864 : */
865 8 : collation = a->array_collid;
866 8 : if (collation == InvalidOid)
867 8 : state = FDW_COLLATE_NONE;
868 0 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
869 0 : collation == inner_cxt.collation)
870 0 : state = FDW_COLLATE_SAFE;
871 0 : else if (collation == DEFAULT_COLLATION_OID)
872 0 : state = FDW_COLLATE_NONE;
873 : else
874 0 : state = FDW_COLLATE_UNSAFE;
875 : }
876 8 : break;
877 3300 : case T_List:
878 : {
879 3300 : List *l = (List *) node;
880 : ListCell *lc;
881 :
882 : /*
883 : * Recurse to component subexpressions.
884 : */
885 9380 : foreach(lc, l)
886 : {
887 6258 : if (!foreign_expr_walker((Node *) lfirst(lc),
888 : glob_cxt, &inner_cxt, case_arg_cxt))
889 178 : return false;
890 : }
891 :
892 : /*
893 : * When processing a list, collation state just bubbles up
894 : * from the list elements.
895 : */
896 3122 : collation = inner_cxt.collation;
897 3122 : state = inner_cxt.state;
898 :
899 : /* Don't apply exprType() to the list. */
900 3122 : check_type = false;
901 : }
902 3122 : break;
903 554 : case T_Aggref:
904 : {
905 554 : Aggref *agg = (Aggref *) node;
906 : ListCell *lc;
907 :
908 : /* Not safe to pushdown when not in grouping context */
909 554 : if (!IS_UPPER_REL(glob_cxt->foreignrel))
910 0 : return false;
911 :
912 : /* Only non-split aggregates are pushable. */
913 554 : if (agg->aggsplit != AGGSPLIT_SIMPLE)
914 0 : return false;
915 :
916 : /* As usual, it must be shippable. */
917 554 : if (!is_shippable(agg->aggfnoid, ProcedureRelationId, fpinfo))
918 8 : return false;
919 :
920 : /*
921 : * Recurse to input args. aggdirectargs, aggorder and
922 : * aggdistinct are all present in args, so no need to check
923 : * their shippability explicitly.
924 : */
925 984 : foreach(lc, agg->args)
926 : {
927 462 : Node *n = (Node *) lfirst(lc);
928 :
929 : /* If TargetEntry, extract the expression from it */
930 462 : if (IsA(n, TargetEntry))
931 : {
932 462 : TargetEntry *tle = (TargetEntry *) n;
933 :
934 462 : n = (Node *) tle->expr;
935 : }
936 :
937 462 : if (!foreign_expr_walker(n,
938 : glob_cxt, &inner_cxt, case_arg_cxt))
939 24 : return false;
940 : }
941 :
942 : /*
943 : * For aggorder elements, check whether the sort operator, if
944 : * specified, is shippable or not.
945 : */
946 522 : if (agg->aggorder)
947 : {
948 140 : foreach(lc, agg->aggorder)
949 : {
950 76 : SortGroupClause *srt = (SortGroupClause *) lfirst(lc);
951 : Oid sortcoltype;
952 : TypeCacheEntry *typentry;
953 : TargetEntry *tle;
954 :
955 76 : tle = get_sortgroupref_tle(srt->tleSortGroupRef,
956 : agg->args);
957 76 : sortcoltype = exprType((Node *) tle->expr);
958 76 : typentry = lookup_type_cache(sortcoltype,
959 : TYPECACHE_LT_OPR | TYPECACHE_GT_OPR);
960 : /* Check shippability of non-default sort operator. */
961 76 : if (srt->sortop != typentry->lt_opr &&
962 28 : srt->sortop != typentry->gt_opr &&
963 12 : !is_shippable(srt->sortop, OperatorRelationId,
964 : fpinfo))
965 8 : return false;
966 : }
967 : }
968 :
969 : /* Check aggregate filter */
970 514 : if (!foreign_expr_walker((Node *) agg->aggfilter,
971 : glob_cxt, &inner_cxt, case_arg_cxt))
972 4 : return false;
973 :
974 : /*
975 : * If aggregate's input collation is not derived from a
976 : * foreign Var, it can't be sent to remote.
977 : */
978 510 : if (agg->inputcollid == InvalidOid)
979 : /* OK, inputs are all noncollatable */ ;
980 44 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
981 44 : agg->inputcollid != inner_cxt.collation)
982 0 : return false;
983 :
984 : /*
985 : * Detect whether node is introducing a collation not derived
986 : * from a foreign Var. (If so, we just mark it unsafe for now
987 : * rather than immediately returning false, since the parent
988 : * node might not care.)
989 : */
990 510 : collation = agg->aggcollid;
991 510 : if (collation == InvalidOid)
992 508 : state = FDW_COLLATE_NONE;
993 2 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
994 2 : collation == inner_cxt.collation)
995 2 : state = FDW_COLLATE_SAFE;
996 0 : else if (collation == DEFAULT_COLLATION_OID)
997 0 : state = FDW_COLLATE_NONE;
998 : else
999 0 : state = FDW_COLLATE_UNSAFE;
1000 : }
1001 510 : break;
1002 60 : default:
1003 :
1004 : /*
1005 : * If it's anything else, assume it's unsafe. This list can be
1006 : * expanded later, but don't forget to add deparse support below.
1007 : */
1008 60 : return false;
1009 : }
1010 :
1011 : /*
1012 : * If result type of given expression is not shippable, it can't be sent
1013 : * to remote because it might have incompatible semantics on remote side.
1014 : */
1015 16868 : if (check_type && !is_shippable(exprType(node), TypeRelationId, fpinfo))
1016 50 : return false;
1017 :
1018 : /*
1019 : * Now, merge my collation information into my parent's state.
1020 : */
1021 16818 : if (state > outer_cxt->state)
1022 : {
1023 : /* Override previous parent state */
1024 960 : outer_cxt->collation = collation;
1025 960 : outer_cxt->state = state;
1026 : }
1027 15858 : else if (state == outer_cxt->state)
1028 : {
1029 : /* Merge, or detect error if there's a collation conflict */
1030 15756 : switch (state)
1031 : {
1032 15732 : case FDW_COLLATE_NONE:
1033 : /* Nothing + nothing is still nothing */
1034 15732 : break;
1035 22 : case FDW_COLLATE_SAFE:
1036 22 : if (collation != outer_cxt->collation)
1037 : {
1038 : /*
1039 : * Non-default collation always beats default.
1040 : */
1041 0 : if (outer_cxt->collation == DEFAULT_COLLATION_OID)
1042 : {
1043 : /* Override previous parent state */
1044 0 : outer_cxt->collation = collation;
1045 : }
1046 0 : else if (collation != DEFAULT_COLLATION_OID)
1047 : {
1048 : /*
1049 : * Conflict; show state as indeterminate. We don't
1050 : * want to "return false" right away, since parent
1051 : * node might not care about collation.
1052 : */
1053 0 : outer_cxt->state = FDW_COLLATE_UNSAFE;
1054 : }
1055 : }
1056 22 : break;
1057 2 : case FDW_COLLATE_UNSAFE:
1058 : /* We're still conflicted ... */
1059 2 : break;
1060 : }
1061 102 : }
1062 :
1063 : /* It looks OK */
1064 16818 : return true;
1065 : }
1066 :
1067 : /*
1068 : * Returns true if given expr is something we'd have to send the value of
1069 : * to the foreign server.
1070 : *
1071 : * This should return true when the expression is a shippable node that
1072 : * deparseExpr would add to context->params_list. Note that we don't care
1073 : * if the expression *contains* such a node, only whether one appears at top
1074 : * level. We need this to detect cases where setrefs.c would recognize a
1075 : * false match between an fdw_exprs item (which came from the params_list)
1076 : * and an entry in fdw_scan_tlist (which we're considering putting the given
1077 : * expression into).
1078 : */
1079 : bool
1080 546 : is_foreign_param(PlannerInfo *root,
1081 : RelOptInfo *baserel,
1082 : Expr *expr)
1083 : {
1084 546 : if (expr == NULL)
1085 0 : return false;
1086 :
1087 546 : switch (nodeTag(expr))
1088 : {
1089 152 : case T_Var:
1090 : {
1091 : /* It would have to be sent unless it's a foreign Var */
1092 152 : Var *var = (Var *) expr;
1093 152 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) (baserel->fdw_private);
1094 : Relids relids;
1095 :
1096 152 : if (IS_UPPER_REL(baserel))
1097 152 : relids = fpinfo->outerrel->relids;
1098 : else
1099 0 : relids = baserel->relids;
1100 :
1101 152 : if (bms_is_member(var->varno, relids) && var->varlevelsup == 0)
1102 152 : return false; /* foreign Var, so not a param */
1103 : else
1104 0 : return true; /* it'd have to be a param */
1105 : break;
1106 : }
1107 8 : case T_Param:
1108 : /* Params always have to be sent to the foreign server */
1109 8 : return true;
1110 386 : default:
1111 386 : break;
1112 : }
1113 386 : return false;
1114 : }
1115 :
1116 : /*
1117 : * Returns true if it's safe to push down the sort expression described by
1118 : * 'pathkey' to the foreign server.
1119 : */
1120 : bool
1121 1522 : is_foreign_pathkey(PlannerInfo *root,
1122 : RelOptInfo *baserel,
1123 : PathKey *pathkey)
1124 : {
1125 1522 : EquivalenceClass *pathkey_ec = pathkey->pk_eclass;
1126 1522 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) baserel->fdw_private;
1127 :
1128 : /*
1129 : * is_foreign_expr would detect volatile expressions as well, but checking
1130 : * ec_has_volatile here saves some cycles.
1131 : */
1132 1522 : if (pathkey_ec->ec_has_volatile)
1133 8 : return false;
1134 :
1135 : /* can't push down the sort if the pathkey's opfamily is not shippable */
1136 1514 : if (!is_shippable(pathkey->pk_opfamily, OperatorFamilyRelationId, fpinfo))
1137 6 : return false;
1138 :
1139 : /* can push if a suitable EC member exists */
1140 1508 : return (find_em_for_rel(root, pathkey_ec, baserel) != NULL);
1141 : }
1142 :
1143 : /*
1144 : * Convert type OID + typmod info into a type name we can ship to the remote
1145 : * server. Someplace else had better have verified that this type name is
1146 : * expected to be known on the remote end.
1147 : *
1148 : * This is almost just format_type_with_typemod(), except that if left to its
1149 : * own devices, that function will make schema-qualification decisions based
1150 : * on the local search_path, which is wrong. We must schema-qualify all
1151 : * type names that are not in pg_catalog. We assume here that built-in types
1152 : * are all in pg_catalog and need not be qualified; otherwise, qualify.
1153 : */
1154 : static char *
1155 1056 : deparse_type_name(Oid type_oid, int32 typemod)
1156 : {
1157 1056 : bits16 flags = FORMAT_TYPE_TYPEMOD_GIVEN;
1158 :
1159 1056 : if (!is_builtin(type_oid))
1160 0 : flags |= FORMAT_TYPE_FORCE_QUALIFY;
1161 :
1162 1056 : return format_type_extended(type_oid, typemod, flags);
1163 : }
1164 :
1165 : /*
1166 : * Build the targetlist for given relation to be deparsed as SELECT clause.
1167 : *
1168 : * The output targetlist contains the columns that need to be fetched from the
1169 : * foreign server for the given relation. If foreignrel is an upper relation,
1170 : * then the output targetlist can also contain expressions to be evaluated on
1171 : * foreign server.
1172 : */
1173 : List *
1174 1524 : build_tlist_to_deparse(RelOptInfo *foreignrel)
1175 : {
1176 1524 : List *tlist = NIL;
1177 1524 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1178 : ListCell *lc;
1179 :
1180 : /*
1181 : * For an upper relation, we have already built the target list while
1182 : * checking shippability, so just return that.
1183 : */
1184 1524 : if (IS_UPPER_REL(foreignrel))
1185 324 : return fpinfo->grouped_tlist;
1186 :
1187 : /*
1188 : * We require columns specified in foreignrel->reltarget->exprs and those
1189 : * required for evaluating the local conditions.
1190 : */
1191 1200 : tlist = add_to_flat_tlist(tlist,
1192 1200 : pull_var_clause((Node *) foreignrel->reltarget->exprs,
1193 : PVC_RECURSE_PLACEHOLDERS));
1194 1248 : foreach(lc, fpinfo->local_conds)
1195 : {
1196 48 : RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
1197 :
1198 48 : tlist = add_to_flat_tlist(tlist,
1199 48 : pull_var_clause((Node *) rinfo->clause,
1200 : PVC_RECURSE_PLACEHOLDERS));
1201 : }
1202 :
1203 1200 : return tlist;
1204 : }
1205 :
1206 : /*
1207 : * Deparse SELECT statement for given relation into buf.
1208 : *
1209 : * tlist contains the list of desired columns to be fetched from foreign server.
1210 : * For a base relation fpinfo->attrs_used is used to construct SELECT clause,
1211 : * hence the tlist is ignored for a base relation.
1212 : *
1213 : * remote_conds is the list of conditions to be deparsed into the WHERE clause
1214 : * (or, in the case of upper relations, into the HAVING clause).
1215 : *
1216 : * If params_list is not NULL, it receives a list of Params and other-relation
1217 : * Vars used in the clauses; these values must be transmitted to the remote
1218 : * server as parameter values.
1219 : *
1220 : * If params_list is NULL, we're generating the query for EXPLAIN purposes,
1221 : * so Params and other-relation Vars should be replaced by dummy values.
1222 : *
1223 : * pathkeys is the list of pathkeys to order the result by.
1224 : *
1225 : * is_subquery is the flag to indicate whether to deparse the specified
1226 : * relation as a subquery.
1227 : *
1228 : * List of columns selected is returned in retrieved_attrs.
1229 : */
1230 : void
1231 4442 : deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *rel,
1232 : List *tlist, List *remote_conds, List *pathkeys,
1233 : bool has_final_sort, bool has_limit, bool is_subquery,
1234 : List **retrieved_attrs, List **params_list)
1235 : {
1236 : deparse_expr_cxt context;
1237 4442 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
1238 : List *quals;
1239 :
1240 : /*
1241 : * We handle relations for foreign tables, joins between those and upper
1242 : * relations.
1243 : */
1244 : Assert(IS_JOIN_REL(rel) || IS_SIMPLE_REL(rel) || IS_UPPER_REL(rel));
1245 :
1246 : /* Fill portions of context common to upper, join and base relation */
1247 4442 : context.buf = buf;
1248 4442 : context.root = root;
1249 4442 : context.foreignrel = rel;
1250 4442 : context.scanrel = IS_UPPER_REL(rel) ? fpinfo->outerrel : rel;
1251 4442 : context.params_list = params_list;
1252 :
1253 : /* Construct SELECT clause */
1254 4442 : deparseSelectSql(tlist, is_subquery, retrieved_attrs, &context);
1255 :
1256 : /*
1257 : * For upper relations, the WHERE clause is built from the remote
1258 : * conditions of the underlying scan relation; otherwise, we can use the
1259 : * supplied list of remote conditions directly.
1260 : */
1261 4442 : if (IS_UPPER_REL(rel))
1262 324 : {
1263 : PgFdwRelationInfo *ofpinfo;
1264 :
1265 324 : ofpinfo = (PgFdwRelationInfo *) fpinfo->outerrel->fdw_private;
1266 324 : quals = ofpinfo->remote_conds;
1267 : }
1268 : else
1269 4118 : quals = remote_conds;
1270 :
1271 : /* Construct FROM and WHERE clauses */
1272 4442 : deparseFromExpr(quals, &context);
1273 :
1274 4442 : if (IS_UPPER_REL(rel))
1275 : {
1276 : /* Append GROUP BY clause */
1277 324 : appendGroupByClause(tlist, &context);
1278 :
1279 : /* Append HAVING clause */
1280 324 : if (remote_conds)
1281 : {
1282 36 : appendStringInfoString(buf, " HAVING ");
1283 36 : appendConditions(remote_conds, &context);
1284 : }
1285 : }
1286 :
1287 : /* Add ORDER BY clause if we found any useful pathkeys */
1288 4442 : if (pathkeys)
1289 1426 : appendOrderByClause(pathkeys, has_final_sort, &context);
1290 :
1291 : /* Add LIMIT clause if necessary */
1292 4442 : if (has_limit)
1293 284 : appendLimitClause(&context);
1294 :
1295 : /* Add any necessary FOR UPDATE/SHARE. */
1296 4442 : deparseLockingClause(&context);
1297 4442 : }
1298 :
1299 : /*
1300 : * Construct a simple SELECT statement that retrieves desired columns
1301 : * of the specified foreign table, and append it to "buf". The output
1302 : * contains just "SELECT ... ".
1303 : *
1304 : * We also create an integer List of the columns being retrieved, which is
1305 : * returned to *retrieved_attrs, unless we deparse the specified relation
1306 : * as a subquery.
1307 : *
1308 : * tlist is the list of desired columns. is_subquery is the flag to
1309 : * indicate whether to deparse the specified relation as a subquery.
1310 : * Read prologue of deparseSelectStmtForRel() for details.
1311 : */
1312 : static void
1313 4442 : deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs,
1314 : deparse_expr_cxt *context)
1315 : {
1316 4442 : StringInfo buf = context->buf;
1317 4442 : RelOptInfo *foreignrel = context->foreignrel;
1318 4442 : PlannerInfo *root = context->root;
1319 4442 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1320 :
1321 : /*
1322 : * Construct SELECT list
1323 : */
1324 4442 : appendStringInfoString(buf, "SELECT ");
1325 :
1326 4442 : if (is_subquery)
1327 : {
1328 : /*
1329 : * For a relation that is deparsed as a subquery, emit expressions
1330 : * specified in the relation's reltarget. Note that since this is for
1331 : * the subquery, no need to care about *retrieved_attrs.
1332 : */
1333 72 : deparseSubqueryTargetList(context);
1334 : }
1335 4370 : else if (IS_JOIN_REL(foreignrel) || IS_UPPER_REL(foreignrel))
1336 : {
1337 : /*
1338 : * For a join or upper relation the input tlist gives the list of
1339 : * columns required to be fetched from the foreign server.
1340 : */
1341 1524 : deparseExplicitTargetList(tlist, false, retrieved_attrs, context);
1342 : }
1343 : else
1344 : {
1345 : /*
1346 : * For a base relation fpinfo->attrs_used gives the list of columns
1347 : * required to be fetched from the foreign server.
1348 : */
1349 2846 : RangeTblEntry *rte = planner_rt_fetch(foreignrel->relid, root);
1350 :
1351 : /*
1352 : * Core code already has some lock on each rel being planned, so we
1353 : * can use NoLock here.
1354 : */
1355 2846 : Relation rel = table_open(rte->relid, NoLock);
1356 :
1357 2846 : deparseTargetList(buf, rte, foreignrel->relid, rel, false,
1358 : fpinfo->attrs_used, false, retrieved_attrs);
1359 2846 : table_close(rel, NoLock);
1360 : }
1361 4442 : }
1362 :
1363 : /*
1364 : * Construct a FROM clause and, if needed, a WHERE clause, and append those to
1365 : * "buf".
1366 : *
1367 : * quals is the list of clauses to be included in the WHERE clause.
1368 : * (These may or may not include RestrictInfo decoration.)
1369 : */
1370 : static void
1371 4442 : deparseFromExpr(List *quals, deparse_expr_cxt *context)
1372 : {
1373 4442 : StringInfo buf = context->buf;
1374 4442 : RelOptInfo *scanrel = context->scanrel;
1375 4442 : List *additional_conds = NIL;
1376 :
1377 : /* For upper relations, scanrel must be either a joinrel or a baserel */
1378 : Assert(!IS_UPPER_REL(context->foreignrel) ||
1379 : IS_JOIN_REL(scanrel) || IS_SIMPLE_REL(scanrel));
1380 :
1381 : /* Construct FROM clause */
1382 4442 : appendStringInfoString(buf, " FROM ");
1383 4442 : deparseFromExprForRel(buf, context->root, scanrel,
1384 4442 : (bms_membership(scanrel->relids) == BMS_MULTIPLE),
1385 : (Index) 0, NULL, &additional_conds,
1386 : context->params_list);
1387 4442 : appendWhereClause(quals, additional_conds, context);
1388 4442 : if (additional_conds != NIL)
1389 256 : list_free_deep(additional_conds);
1390 4442 : }
1391 :
1392 : /*
1393 : * Emit a target list that retrieves the columns specified in attrs_used.
1394 : * This is used for both SELECT and RETURNING targetlists; the is_returning
1395 : * parameter is true only for a RETURNING targetlist.
1396 : *
1397 : * The tlist text is appended to buf, and we also create an integer List
1398 : * of the columns being retrieved, which is returned to *retrieved_attrs.
1399 : *
1400 : * If qualify_col is true, add relation alias before the column name.
1401 : */
1402 : static void
1403 3534 : deparseTargetList(StringInfo buf,
1404 : RangeTblEntry *rte,
1405 : Index rtindex,
1406 : Relation rel,
1407 : bool is_returning,
1408 : Bitmapset *attrs_used,
1409 : bool qualify_col,
1410 : List **retrieved_attrs)
1411 : {
1412 3534 : TupleDesc tupdesc = RelationGetDescr(rel);
1413 : bool have_wholerow;
1414 : bool first;
1415 : int i;
1416 :
1417 3534 : *retrieved_attrs = NIL;
1418 :
1419 : /* If there's a whole-row reference, we'll need all the columns. */
1420 3534 : have_wholerow = bms_is_member(0 - FirstLowInvalidHeapAttributeNumber,
1421 : attrs_used);
1422 :
1423 3534 : first = true;
1424 25362 : for (i = 1; i <= tupdesc->natts; i++)
1425 : {
1426 21828 : Form_pg_attribute attr = TupleDescAttr(tupdesc, i - 1);
1427 :
1428 : /* Ignore dropped attributes. */
1429 21828 : if (attr->attisdropped)
1430 1964 : continue;
1431 :
1432 33620 : if (have_wholerow ||
1433 13756 : bms_is_member(i - FirstLowInvalidHeapAttributeNumber,
1434 : attrs_used))
1435 : {
1436 12278 : if (!first)
1437 8978 : appendStringInfoString(buf, ", ");
1438 3300 : else if (is_returning)
1439 212 : appendStringInfoString(buf, " RETURNING ");
1440 12278 : first = false;
1441 :
1442 12278 : deparseColumnRef(buf, rtindex, i, rte, qualify_col);
1443 :
1444 12278 : *retrieved_attrs = lappend_int(*retrieved_attrs, i);
1445 : }
1446 : }
1447 :
1448 : /*
1449 : * Add ctid if needed. We currently don't support retrieving any other
1450 : * system columns.
1451 : */
1452 3534 : if (bms_is_member(SelfItemPointerAttributeNumber - FirstLowInvalidHeapAttributeNumber,
1453 : attrs_used))
1454 : {
1455 564 : if (!first)
1456 428 : appendStringInfoString(buf, ", ");
1457 136 : else if (is_returning)
1458 0 : appendStringInfoString(buf, " RETURNING ");
1459 564 : first = false;
1460 :
1461 564 : if (qualify_col)
1462 0 : ADD_REL_QUALIFIER(buf, rtindex);
1463 564 : appendStringInfoString(buf, "ctid");
1464 :
1465 564 : *retrieved_attrs = lappend_int(*retrieved_attrs,
1466 : SelfItemPointerAttributeNumber);
1467 : }
1468 :
1469 : /* Don't generate bad syntax if no undropped columns */
1470 3534 : if (first && !is_returning)
1471 86 : appendStringInfoString(buf, "NULL");
1472 3534 : }
1473 :
1474 : /*
1475 : * Deparse the appropriate locking clause (FOR UPDATE or FOR SHARE) for a
1476 : * given relation (context->scanrel).
1477 : */
1478 : static void
1479 4442 : deparseLockingClause(deparse_expr_cxt *context)
1480 : {
1481 4442 : StringInfo buf = context->buf;
1482 4442 : PlannerInfo *root = context->root;
1483 4442 : RelOptInfo *rel = context->scanrel;
1484 4442 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
1485 4442 : int relid = -1;
1486 :
1487 11084 : while ((relid = bms_next_member(rel->relids, relid)) >= 0)
1488 : {
1489 : /*
1490 : * Ignore relation if it appears in a lower subquery. Locking clause
1491 : * for such a relation is included in the subquery if necessary.
1492 : */
1493 6642 : if (bms_is_member(relid, fpinfo->lower_subquery_rels))
1494 104 : continue;
1495 :
1496 : /*
1497 : * Add FOR UPDATE/SHARE if appropriate. We apply locking during the
1498 : * initial row fetch, rather than later on as is done for local
1499 : * tables. The extra roundtrips involved in trying to duplicate the
1500 : * local semantics exactly don't seem worthwhile (see also comments
1501 : * for RowMarkType).
1502 : *
1503 : * Note: because we actually run the query as a cursor, this assumes
1504 : * that DECLARE CURSOR ... FOR UPDATE is supported, which it isn't
1505 : * before 8.3.
1506 : */
1507 6538 : if (bms_is_member(relid, root->all_result_relids) &&
1508 558 : (root->parse->commandType == CMD_UPDATE ||
1509 240 : root->parse->commandType == CMD_DELETE))
1510 : {
1511 : /* Relation is UPDATE/DELETE target, so use FOR UPDATE */
1512 554 : appendStringInfoString(buf, " FOR UPDATE");
1513 :
1514 : /* Add the relation alias if we are here for a join relation */
1515 554 : if (IS_JOIN_REL(rel))
1516 84 : appendStringInfo(buf, " OF %s%d", REL_ALIAS_PREFIX, relid);
1517 : }
1518 : else
1519 : {
1520 5984 : PlanRowMark *rc = get_plan_rowmark(root->rowMarks, relid);
1521 :
1522 5984 : if (rc)
1523 : {
1524 : /*
1525 : * Relation is specified as a FOR UPDATE/SHARE target, so
1526 : * handle that. (But we could also see LCS_NONE, meaning this
1527 : * isn't a target relation after all.)
1528 : *
1529 : * For now, just ignore any [NO] KEY specification, since (a)
1530 : * it's not clear what that means for a remote table that we
1531 : * don't have complete information about, and (b) it wouldn't
1532 : * work anyway on older remote servers. Likewise, we don't
1533 : * worry about NOWAIT.
1534 : */
1535 656 : switch (rc->strength)
1536 : {
1537 352 : case LCS_NONE:
1538 : /* No locking needed */
1539 352 : break;
1540 76 : case LCS_FORKEYSHARE:
1541 : case LCS_FORSHARE:
1542 76 : appendStringInfoString(buf, " FOR SHARE");
1543 76 : break;
1544 228 : case LCS_FORNOKEYUPDATE:
1545 : case LCS_FORUPDATE:
1546 228 : appendStringInfoString(buf, " FOR UPDATE");
1547 228 : break;
1548 : }
1549 :
1550 : /* Add the relation alias if we are here for a join relation */
1551 656 : if (bms_membership(rel->relids) == BMS_MULTIPLE &&
1552 380 : rc->strength != LCS_NONE)
1553 208 : appendStringInfo(buf, " OF %s%d", REL_ALIAS_PREFIX, relid);
1554 : }
1555 : }
1556 : }
1557 4442 : }
1558 :
1559 : /*
1560 : * Deparse conditions from the provided list and append them to buf.
1561 : *
1562 : * The conditions in the list are assumed to be ANDed. This function is used to
1563 : * deparse WHERE clauses, JOIN .. ON clauses and HAVING clauses.
1564 : *
1565 : * Depending on the caller, the list elements might be either RestrictInfos
1566 : * or bare clauses.
1567 : */
1568 : static void
1569 3524 : appendConditions(List *exprs, deparse_expr_cxt *context)
1570 : {
1571 : int nestlevel;
1572 : ListCell *lc;
1573 3524 : bool is_first = true;
1574 3524 : StringInfo buf = context->buf;
1575 :
1576 : /* Make sure any constants in the exprs are printed portably */
1577 3524 : nestlevel = set_transmission_modes();
1578 :
1579 8098 : foreach(lc, exprs)
1580 : {
1581 4574 : Expr *expr = (Expr *) lfirst(lc);
1582 :
1583 : /* Extract clause from RestrictInfo, if required */
1584 4574 : if (IsA(expr, RestrictInfo))
1585 3888 : expr = ((RestrictInfo *) expr)->clause;
1586 :
1587 : /* Connect expressions with "AND" and parenthesize each condition. */
1588 4574 : if (!is_first)
1589 1050 : appendStringInfoString(buf, " AND ");
1590 :
1591 4574 : appendStringInfoChar(buf, '(');
1592 4574 : deparseExpr(expr, context);
1593 4574 : appendStringInfoChar(buf, ')');
1594 :
1595 4574 : is_first = false;
1596 : }
1597 :
1598 3524 : reset_transmission_modes(nestlevel);
1599 3524 : }
1600 :
1601 : /*
1602 : * Append WHERE clause, containing conditions from exprs and additional_conds,
1603 : * to context->buf.
1604 : */
1605 : static void
1606 4970 : appendWhereClause(List *exprs, List *additional_conds, deparse_expr_cxt *context)
1607 : {
1608 4970 : StringInfo buf = context->buf;
1609 4970 : bool need_and = false;
1610 : ListCell *lc;
1611 :
1612 4970 : if (exprs != NIL || additional_conds != NIL)
1613 2282 : appendStringInfoString(buf, " WHERE ");
1614 :
1615 : /*
1616 : * If there are some filters, append them.
1617 : */
1618 4970 : if (exprs != NIL)
1619 : {
1620 2076 : appendConditions(exprs, context);
1621 2076 : need_and = true;
1622 : }
1623 :
1624 : /*
1625 : * If there are some EXISTS conditions, coming from SEMI-JOINS, append
1626 : * them.
1627 : */
1628 5290 : foreach(lc, additional_conds)
1629 : {
1630 320 : if (need_and)
1631 114 : appendStringInfoString(buf, " AND ");
1632 320 : appendStringInfoString(buf, (char *) lfirst(lc));
1633 320 : need_and = true;
1634 : }
1635 4970 : }
1636 :
1637 : /* Output join name for given join type */
1638 : const char *
1639 2074 : get_jointype_name(JoinType jointype)
1640 : {
1641 2074 : switch (jointype)
1642 : {
1643 1382 : case JOIN_INNER:
1644 1382 : return "INNER";
1645 :
1646 400 : case JOIN_LEFT:
1647 400 : return "LEFT";
1648 :
1649 0 : case JOIN_RIGHT:
1650 0 : return "RIGHT";
1651 :
1652 216 : case JOIN_FULL:
1653 216 : return "FULL";
1654 :
1655 76 : case JOIN_SEMI:
1656 76 : return "SEMI";
1657 :
1658 0 : default:
1659 : /* Shouldn't come here, but protect from buggy code. */
1660 0 : elog(ERROR, "unsupported join type %d", jointype);
1661 : }
1662 :
1663 : /* Keep compiler happy */
1664 : return NULL;
1665 : }
1666 :
1667 : /*
1668 : * Deparse given targetlist and append it to context->buf.
1669 : *
1670 : * tlist is list of TargetEntry's which in turn contain Var nodes.
1671 : *
1672 : * retrieved_attrs is the list of continuously increasing integers starting
1673 : * from 1. It has same number of entries as tlist.
1674 : *
1675 : * This is used for both SELECT and RETURNING targetlists; the is_returning
1676 : * parameter is true only for a RETURNING targetlist.
1677 : */
1678 : static void
1679 1540 : deparseExplicitTargetList(List *tlist,
1680 : bool is_returning,
1681 : List **retrieved_attrs,
1682 : deparse_expr_cxt *context)
1683 : {
1684 : ListCell *lc;
1685 1540 : StringInfo buf = context->buf;
1686 1540 : int i = 0;
1687 :
1688 1540 : *retrieved_attrs = NIL;
1689 :
1690 9204 : foreach(lc, tlist)
1691 : {
1692 7664 : TargetEntry *tle = lfirst_node(TargetEntry, lc);
1693 :
1694 7664 : if (i > 0)
1695 6140 : appendStringInfoString(buf, ", ");
1696 1524 : else if (is_returning)
1697 4 : appendStringInfoString(buf, " RETURNING ");
1698 :
1699 7664 : deparseExpr((Expr *) tle->expr, context);
1700 :
1701 7664 : *retrieved_attrs = lappend_int(*retrieved_attrs, i + 1);
1702 7664 : i++;
1703 : }
1704 :
1705 1540 : if (i == 0 && !is_returning)
1706 4 : appendStringInfoString(buf, "NULL");
1707 1540 : }
1708 :
1709 : /*
1710 : * Emit expressions specified in the given relation's reltarget.
1711 : *
1712 : * This is used for deparsing the given relation as a subquery.
1713 : */
1714 : static void
1715 72 : deparseSubqueryTargetList(deparse_expr_cxt *context)
1716 : {
1717 72 : StringInfo buf = context->buf;
1718 72 : RelOptInfo *foreignrel = context->foreignrel;
1719 : bool first;
1720 : ListCell *lc;
1721 :
1722 : /* Should only be called in these cases. */
1723 : Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
1724 :
1725 72 : first = true;
1726 184 : foreach(lc, foreignrel->reltarget->exprs)
1727 : {
1728 112 : Node *node = (Node *) lfirst(lc);
1729 :
1730 112 : if (!first)
1731 48 : appendStringInfoString(buf, ", ");
1732 112 : first = false;
1733 :
1734 112 : deparseExpr((Expr *) node, context);
1735 : }
1736 :
1737 : /* Don't generate bad syntax if no expressions */
1738 72 : if (first)
1739 8 : appendStringInfoString(buf, "NULL");
1740 72 : }
1741 :
1742 : /*
1743 : * Construct FROM clause for given relation
1744 : *
1745 : * The function constructs ... JOIN ... ON ... for join relation. For a base
1746 : * relation it just returns schema-qualified tablename, with the appropriate
1747 : * alias if so requested.
1748 : *
1749 : * 'ignore_rel' is either zero or the RT index of a target relation. In the
1750 : * latter case the function constructs FROM clause of UPDATE or USING clause
1751 : * of DELETE; it deparses the join relation as if the relation never contained
1752 : * the target relation, and creates a List of conditions to be deparsed into
1753 : * the top-level WHERE clause, which is returned to *ignore_conds.
1754 : *
1755 : * 'additional_conds' is a pointer to a list of strings to be appended to
1756 : * the WHERE clause, coming from lower-level SEMI-JOINs.
1757 : */
1758 : static void
1759 7954 : deparseFromExprForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
1760 : bool use_alias, Index ignore_rel, List **ignore_conds,
1761 : List **additional_conds, List **params_list)
1762 : {
1763 7954 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1764 :
1765 7954 : if (IS_JOIN_REL(foreignrel))
1766 1776 : {
1767 : StringInfoData join_sql_o;
1768 : StringInfoData join_sql_i;
1769 1792 : RelOptInfo *outerrel = fpinfo->outerrel;
1770 1792 : RelOptInfo *innerrel = fpinfo->innerrel;
1771 1792 : bool outerrel_is_target = false;
1772 1792 : bool innerrel_is_target = false;
1773 1792 : List *additional_conds_i = NIL;
1774 1792 : List *additional_conds_o = NIL;
1775 :
1776 1792 : if (ignore_rel > 0 && bms_is_member(ignore_rel, foreignrel->relids))
1777 : {
1778 : /*
1779 : * If this is an inner join, add joinclauses to *ignore_conds and
1780 : * set it to empty so that those can be deparsed into the WHERE
1781 : * clause. Note that since the target relation can never be
1782 : * within the nullable side of an outer join, those could safely
1783 : * be pulled up into the WHERE clause (see foreign_join_ok()).
1784 : * Note also that since the target relation is only inner-joined
1785 : * to any other relation in the query, all conditions in the join
1786 : * tree mentioning the target relation could be deparsed into the
1787 : * WHERE clause by doing this recursively.
1788 : */
1789 24 : if (fpinfo->jointype == JOIN_INNER)
1790 : {
1791 40 : *ignore_conds = list_concat(*ignore_conds,
1792 20 : fpinfo->joinclauses);
1793 20 : fpinfo->joinclauses = NIL;
1794 : }
1795 :
1796 : /*
1797 : * Check if either of the input relations is the target relation.
1798 : */
1799 24 : if (outerrel->relid == ignore_rel)
1800 16 : outerrel_is_target = true;
1801 8 : else if (innerrel->relid == ignore_rel)
1802 0 : innerrel_is_target = true;
1803 : }
1804 :
1805 : /* Deparse outer relation if not the target relation. */
1806 1792 : if (!outerrel_is_target)
1807 : {
1808 1776 : initStringInfo(&join_sql_o);
1809 1776 : deparseRangeTblRef(&join_sql_o, root, outerrel,
1810 1776 : fpinfo->make_outerrel_subquery,
1811 : ignore_rel, ignore_conds, &additional_conds_o,
1812 : params_list);
1813 :
1814 : /*
1815 : * If inner relation is the target relation, skip deparsing it.
1816 : * Note that since the join of the target relation with any other
1817 : * relation in the query is an inner join and can never be within
1818 : * the nullable side of an outer join, the join could be
1819 : * interchanged with higher-level joins (cf. identity 1 on outer
1820 : * join reordering shown in src/backend/optimizer/README), which
1821 : * means it's safe to skip the target-relation deparsing here.
1822 : */
1823 1776 : if (innerrel_is_target)
1824 : {
1825 : Assert(fpinfo->jointype == JOIN_INNER);
1826 : Assert(fpinfo->joinclauses == NIL);
1827 0 : appendBinaryStringInfo(buf, join_sql_o.data, join_sql_o.len);
1828 : /* Pass EXISTS conditions to upper level */
1829 0 : if (additional_conds_o != NIL)
1830 : {
1831 : Assert(*additional_conds == NIL);
1832 0 : *additional_conds = additional_conds_o;
1833 : }
1834 16 : return;
1835 : }
1836 : }
1837 :
1838 : /* Deparse inner relation if not the target relation. */
1839 1792 : if (!innerrel_is_target)
1840 : {
1841 1792 : initStringInfo(&join_sql_i);
1842 1792 : deparseRangeTblRef(&join_sql_i, root, innerrel,
1843 1792 : fpinfo->make_innerrel_subquery,
1844 : ignore_rel, ignore_conds, &additional_conds_i,
1845 : params_list);
1846 :
1847 : /*
1848 : * SEMI-JOIN is deparsed as the EXISTS subquery. It references
1849 : * outer and inner relations, so it should be evaluated as the
1850 : * condition in the upper-level WHERE clause. We deparse the
1851 : * condition and pass it to upper level callers as an
1852 : * additional_conds list. Upper level callers are responsible for
1853 : * inserting conditions from the list where appropriate.
1854 : */
1855 1792 : if (fpinfo->jointype == JOIN_SEMI)
1856 : {
1857 : deparse_expr_cxt context;
1858 : StringInfoData str;
1859 :
1860 : /* Construct deparsed condition from this SEMI-JOIN */
1861 320 : initStringInfo(&str);
1862 320 : appendStringInfo(&str, "EXISTS (SELECT NULL FROM %s",
1863 : join_sql_i.data);
1864 :
1865 320 : context.buf = &str;
1866 320 : context.foreignrel = foreignrel;
1867 320 : context.scanrel = foreignrel;
1868 320 : context.root = root;
1869 320 : context.params_list = params_list;
1870 :
1871 : /*
1872 : * Append SEMI-JOIN clauses and EXISTS conditions from lower
1873 : * levels to the current EXISTS subquery
1874 : */
1875 320 : appendWhereClause(fpinfo->joinclauses, additional_conds_i, &context);
1876 :
1877 : /*
1878 : * EXISTS conditions, coming from lower join levels, have just
1879 : * been processed.
1880 : */
1881 320 : if (additional_conds_i != NIL)
1882 : {
1883 32 : list_free_deep(additional_conds_i);
1884 32 : additional_conds_i = NIL;
1885 : }
1886 :
1887 : /* Close parentheses for EXISTS subquery */
1888 320 : appendStringInfoChar(&str, ')');
1889 :
1890 320 : *additional_conds = lappend(*additional_conds, str.data);
1891 : }
1892 :
1893 : /*
1894 : * If outer relation is the target relation, skip deparsing it.
1895 : * See the above note about safety.
1896 : */
1897 1792 : if (outerrel_is_target)
1898 : {
1899 : Assert(fpinfo->jointype == JOIN_INNER);
1900 : Assert(fpinfo->joinclauses == NIL);
1901 16 : appendBinaryStringInfo(buf, join_sql_i.data, join_sql_i.len);
1902 : /* Pass EXISTS conditions to the upper call */
1903 16 : if (additional_conds_i != NIL)
1904 : {
1905 : Assert(*additional_conds == NIL);
1906 0 : *additional_conds = additional_conds_i;
1907 : }
1908 16 : return;
1909 : }
1910 : }
1911 :
1912 : /* Neither of the relations is the target relation. */
1913 : Assert(!outerrel_is_target && !innerrel_is_target);
1914 :
1915 : /*
1916 : * For semijoin FROM clause is deparsed as an outer relation. An inner
1917 : * relation and join clauses are converted to EXISTS condition and
1918 : * passed to the upper level.
1919 : */
1920 1776 : if (fpinfo->jointype == JOIN_SEMI)
1921 : {
1922 320 : appendBinaryStringInfo(buf, join_sql_o.data, join_sql_o.len);
1923 : }
1924 : else
1925 : {
1926 : /*
1927 : * For a join relation FROM clause, entry is deparsed as
1928 : *
1929 : * ((outer relation) <join type> (inner relation) ON
1930 : * (joinclauses))
1931 : */
1932 1456 : appendStringInfo(buf, "(%s %s JOIN %s ON ", join_sql_o.data,
1933 : get_jointype_name(fpinfo->jointype), join_sql_i.data);
1934 :
1935 : /* Append join clause; (TRUE) if no join clause */
1936 1456 : if (fpinfo->joinclauses)
1937 : {
1938 : deparse_expr_cxt context;
1939 :
1940 1412 : context.buf = buf;
1941 1412 : context.foreignrel = foreignrel;
1942 1412 : context.scanrel = foreignrel;
1943 1412 : context.root = root;
1944 1412 : context.params_list = params_list;
1945 :
1946 1412 : appendStringInfoChar(buf, '(');
1947 1412 : appendConditions(fpinfo->joinclauses, &context);
1948 1412 : appendStringInfoChar(buf, ')');
1949 : }
1950 : else
1951 44 : appendStringInfoString(buf, "(TRUE)");
1952 :
1953 : /* End the FROM clause entry. */
1954 1456 : appendStringInfoChar(buf, ')');
1955 : }
1956 :
1957 : /*
1958 : * Construct additional_conds to be passed to the upper caller from
1959 : * current level additional_conds and additional_conds, coming from
1960 : * inner and outer rels.
1961 : */
1962 1776 : if (additional_conds_o != NIL)
1963 : {
1964 96 : *additional_conds = list_concat(*additional_conds,
1965 : additional_conds_o);
1966 96 : list_free(additional_conds_o);
1967 : }
1968 :
1969 1776 : if (additional_conds_i != NIL)
1970 : {
1971 0 : *additional_conds = list_concat(*additional_conds,
1972 : additional_conds_i);
1973 0 : list_free(additional_conds_i);
1974 : }
1975 : }
1976 : else
1977 : {
1978 6162 : RangeTblEntry *rte = planner_rt_fetch(foreignrel->relid, root);
1979 :
1980 : /*
1981 : * Core code already has some lock on each rel being planned, so we
1982 : * can use NoLock here.
1983 : */
1984 6162 : Relation rel = table_open(rte->relid, NoLock);
1985 :
1986 6162 : deparseRelation(buf, rel);
1987 :
1988 : /*
1989 : * Add a unique alias to avoid any conflict in relation names due to
1990 : * pulled up subqueries in the query being built for a pushed down
1991 : * join.
1992 : */
1993 6162 : if (use_alias)
1994 2980 : appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, foreignrel->relid);
1995 :
1996 6162 : table_close(rel, NoLock);
1997 : }
1998 : }
1999 :
2000 : /*
2001 : * Append FROM clause entry for the given relation into buf.
2002 : * Conditions from lower-level SEMI-JOINs are appended to additional_conds
2003 : * and should be added to upper level WHERE clause.
2004 : */
2005 : static void
2006 3568 : deparseRangeTblRef(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
2007 : bool make_subquery, Index ignore_rel, List **ignore_conds,
2008 : List **additional_conds, List **params_list)
2009 : {
2010 3568 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
2011 :
2012 : /* Should only be called in these cases. */
2013 : Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
2014 :
2015 : Assert(fpinfo->local_conds == NIL);
2016 :
2017 : /* If make_subquery is true, deparse the relation as a subquery. */
2018 3568 : if (make_subquery)
2019 : {
2020 : List *retrieved_attrs;
2021 : int ncols;
2022 :
2023 : /*
2024 : * The given relation shouldn't contain the target relation, because
2025 : * this should only happen for input relations for a full join, and
2026 : * such relations can never contain an UPDATE/DELETE target.
2027 : */
2028 : Assert(ignore_rel == 0 ||
2029 : !bms_is_member(ignore_rel, foreignrel->relids));
2030 :
2031 : /* Deparse the subquery representing the relation. */
2032 72 : appendStringInfoChar(buf, '(');
2033 72 : deparseSelectStmtForRel(buf, root, foreignrel, NIL,
2034 : fpinfo->remote_conds, NIL,
2035 : false, false, true,
2036 : &retrieved_attrs, params_list);
2037 72 : appendStringInfoChar(buf, ')');
2038 :
2039 : /* Append the relation alias. */
2040 72 : appendStringInfo(buf, " %s%d", SUBQUERY_REL_ALIAS_PREFIX,
2041 : fpinfo->relation_index);
2042 :
2043 : /*
2044 : * Append the column aliases if needed. Note that the subquery emits
2045 : * expressions specified in the relation's reltarget (see
2046 : * deparseSubqueryTargetList).
2047 : */
2048 72 : ncols = list_length(foreignrel->reltarget->exprs);
2049 72 : if (ncols > 0)
2050 : {
2051 : int i;
2052 :
2053 64 : appendStringInfoChar(buf, '(');
2054 176 : for (i = 1; i <= ncols; i++)
2055 : {
2056 112 : if (i > 1)
2057 48 : appendStringInfoString(buf, ", ");
2058 :
2059 112 : appendStringInfo(buf, "%s%d", SUBQUERY_COL_ALIAS_PREFIX, i);
2060 : }
2061 64 : appendStringInfoChar(buf, ')');
2062 : }
2063 : }
2064 : else
2065 3496 : deparseFromExprForRel(buf, root, foreignrel, true, ignore_rel,
2066 : ignore_conds, additional_conds,
2067 : params_list);
2068 3568 : }
2069 :
2070 : /*
2071 : * deparse remote INSERT statement
2072 : *
2073 : * The statement text is appended to buf, and we also create an integer List
2074 : * of the columns being retrieved by WITH CHECK OPTION or RETURNING (if any),
2075 : * which is returned to *retrieved_attrs.
2076 : *
2077 : * This also stores end position of the VALUES clause, so that we can rebuild
2078 : * an INSERT for a batch of rows later.
2079 : */
2080 : void
2081 282 : deparseInsertSql(StringInfo buf, RangeTblEntry *rte,
2082 : Index rtindex, Relation rel,
2083 : List *targetAttrs, bool doNothing,
2084 : List *withCheckOptionList, List *returningList,
2085 : List **retrieved_attrs, int *values_end_len)
2086 : {
2087 282 : TupleDesc tupdesc = RelationGetDescr(rel);
2088 : AttrNumber pindex;
2089 : bool first;
2090 : ListCell *lc;
2091 :
2092 282 : appendStringInfoString(buf, "INSERT INTO ");
2093 282 : deparseRelation(buf, rel);
2094 :
2095 282 : if (targetAttrs)
2096 : {
2097 280 : appendStringInfoChar(buf, '(');
2098 :
2099 280 : first = true;
2100 1040 : foreach(lc, targetAttrs)
2101 : {
2102 760 : int attnum = lfirst_int(lc);
2103 :
2104 760 : if (!first)
2105 480 : appendStringInfoString(buf, ", ");
2106 760 : first = false;
2107 :
2108 760 : deparseColumnRef(buf, rtindex, attnum, rte, false);
2109 : }
2110 :
2111 280 : appendStringInfoString(buf, ") VALUES (");
2112 :
2113 280 : pindex = 1;
2114 280 : first = true;
2115 1040 : foreach(lc, targetAttrs)
2116 : {
2117 760 : int attnum = lfirst_int(lc);
2118 760 : Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
2119 :
2120 760 : if (!first)
2121 480 : appendStringInfoString(buf, ", ");
2122 760 : first = false;
2123 :
2124 760 : if (attr->attgenerated)
2125 10 : appendStringInfoString(buf, "DEFAULT");
2126 : else
2127 : {
2128 750 : appendStringInfo(buf, "$%d", pindex);
2129 750 : pindex++;
2130 : }
2131 : }
2132 :
2133 280 : appendStringInfoChar(buf, ')');
2134 : }
2135 : else
2136 2 : appendStringInfoString(buf, " DEFAULT VALUES");
2137 282 : *values_end_len = buf->len;
2138 :
2139 282 : if (doNothing)
2140 6 : appendStringInfoString(buf, " ON CONFLICT DO NOTHING");
2141 :
2142 282 : deparseReturningList(buf, rte, rtindex, rel,
2143 282 : rel->trigdesc && rel->trigdesc->trig_insert_after_row,
2144 : withCheckOptionList, returningList, retrieved_attrs);
2145 282 : }
2146 :
2147 : /*
2148 : * rebuild remote INSERT statement
2149 : *
2150 : * Provided a number of rows in a batch, builds INSERT statement with the
2151 : * right number of parameters.
2152 : */
2153 : void
2154 52 : rebuildInsertSql(StringInfo buf, Relation rel,
2155 : char *orig_query, List *target_attrs,
2156 : int values_end_len, int num_params,
2157 : int num_rows)
2158 : {
2159 52 : TupleDesc tupdesc = RelationGetDescr(rel);
2160 : int i;
2161 : int pindex;
2162 : bool first;
2163 : ListCell *lc;
2164 :
2165 : /* Make sure the values_end_len is sensible */
2166 : Assert((values_end_len > 0) && (values_end_len <= strlen(orig_query)));
2167 :
2168 : /* Copy up to the end of the first record from the original query */
2169 52 : appendBinaryStringInfo(buf, orig_query, values_end_len);
2170 :
2171 : /*
2172 : * Add records to VALUES clause (we already have parameters for the first
2173 : * row, so start at the right offset).
2174 : */
2175 52 : pindex = num_params + 1;
2176 206 : for (i = 0; i < num_rows; i++)
2177 : {
2178 154 : appendStringInfoString(buf, ", (");
2179 :
2180 154 : first = true;
2181 450 : foreach(lc, target_attrs)
2182 : {
2183 296 : int attnum = lfirst_int(lc);
2184 296 : Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
2185 :
2186 296 : if (!first)
2187 142 : appendStringInfoString(buf, ", ");
2188 296 : first = false;
2189 :
2190 296 : if (attr->attgenerated)
2191 2 : appendStringInfoString(buf, "DEFAULT");
2192 : else
2193 : {
2194 294 : appendStringInfo(buf, "$%d", pindex);
2195 294 : pindex++;
2196 : }
2197 : }
2198 :
2199 154 : appendStringInfoChar(buf, ')');
2200 : }
2201 :
2202 : /* Copy stuff after VALUES clause from the original query */
2203 52 : appendStringInfoString(buf, orig_query + values_end_len);
2204 52 : }
2205 :
2206 : /*
2207 : * deparse remote UPDATE statement
2208 : *
2209 : * The statement text is appended to buf, and we also create an integer List
2210 : * of the columns being retrieved by WITH CHECK OPTION or RETURNING (if any),
2211 : * which is returned to *retrieved_attrs.
2212 : */
2213 : void
2214 104 : deparseUpdateSql(StringInfo buf, RangeTblEntry *rte,
2215 : Index rtindex, Relation rel,
2216 : List *targetAttrs,
2217 : List *withCheckOptionList, List *returningList,
2218 : List **retrieved_attrs)
2219 : {
2220 104 : TupleDesc tupdesc = RelationGetDescr(rel);
2221 : AttrNumber pindex;
2222 : bool first;
2223 : ListCell *lc;
2224 :
2225 104 : appendStringInfoString(buf, "UPDATE ");
2226 104 : deparseRelation(buf, rel);
2227 104 : appendStringInfoString(buf, " SET ");
2228 :
2229 104 : pindex = 2; /* ctid is always the first param */
2230 104 : first = true;
2231 254 : foreach(lc, targetAttrs)
2232 : {
2233 150 : int attnum = lfirst_int(lc);
2234 150 : Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
2235 :
2236 150 : if (!first)
2237 46 : appendStringInfoString(buf, ", ");
2238 150 : first = false;
2239 :
2240 150 : deparseColumnRef(buf, rtindex, attnum, rte, false);
2241 150 : if (attr->attgenerated)
2242 4 : appendStringInfoString(buf, " = DEFAULT");
2243 : else
2244 : {
2245 146 : appendStringInfo(buf, " = $%d", pindex);
2246 146 : pindex++;
2247 : }
2248 : }
2249 104 : appendStringInfoString(buf, " WHERE ctid = $1");
2250 :
2251 104 : deparseReturningList(buf, rte, rtindex, rel,
2252 104 : rel->trigdesc && rel->trigdesc->trig_update_after_row,
2253 : withCheckOptionList, returningList, retrieved_attrs);
2254 104 : }
2255 :
2256 : /*
2257 : * deparse remote UPDATE statement
2258 : *
2259 : * 'buf' is the output buffer to append the statement to
2260 : * 'rtindex' is the RT index of the associated target relation
2261 : * 'rel' is the relation descriptor for the target relation
2262 : * 'foreignrel' is the RelOptInfo for the target relation or the join relation
2263 : * containing all base relations in the query
2264 : * 'targetlist' is the tlist of the underlying foreign-scan plan node
2265 : * (note that this only contains new-value expressions and junk attrs)
2266 : * 'targetAttrs' is the target columns of the UPDATE
2267 : * 'remote_conds' is the qual clauses that must be evaluated remotely
2268 : * '*params_list' is an output list of exprs that will become remote Params
2269 : * 'returningList' is the RETURNING targetlist
2270 : * '*retrieved_attrs' is an output list of integers of columns being retrieved
2271 : * by RETURNING (if any)
2272 : */
2273 : void
2274 90 : deparseDirectUpdateSql(StringInfo buf, PlannerInfo *root,
2275 : Index rtindex, Relation rel,
2276 : RelOptInfo *foreignrel,
2277 : List *targetlist,
2278 : List *targetAttrs,
2279 : List *remote_conds,
2280 : List **params_list,
2281 : List *returningList,
2282 : List **retrieved_attrs)
2283 : {
2284 : deparse_expr_cxt context;
2285 : int nestlevel;
2286 : bool first;
2287 90 : RangeTblEntry *rte = planner_rt_fetch(rtindex, root);
2288 : ListCell *lc,
2289 : *lc2;
2290 90 : List *additional_conds = NIL;
2291 :
2292 : /* Set up context struct for recursion */
2293 90 : context.root = root;
2294 90 : context.foreignrel = foreignrel;
2295 90 : context.scanrel = foreignrel;
2296 90 : context.buf = buf;
2297 90 : context.params_list = params_list;
2298 :
2299 90 : appendStringInfoString(buf, "UPDATE ");
2300 90 : deparseRelation(buf, rel);
2301 90 : if (foreignrel->reloptkind == RELOPT_JOINREL)
2302 8 : appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, rtindex);
2303 90 : appendStringInfoString(buf, " SET ");
2304 :
2305 : /* Make sure any constants in the exprs are printed portably */
2306 90 : nestlevel = set_transmission_modes();
2307 :
2308 90 : first = true;
2309 196 : forboth(lc, targetlist, lc2, targetAttrs)
2310 : {
2311 106 : TargetEntry *tle = lfirst_node(TargetEntry, lc);
2312 106 : int attnum = lfirst_int(lc2);
2313 :
2314 : /* update's new-value expressions shouldn't be resjunk */
2315 : Assert(!tle->resjunk);
2316 :
2317 106 : if (!first)
2318 16 : appendStringInfoString(buf, ", ");
2319 106 : first = false;
2320 :
2321 106 : deparseColumnRef(buf, rtindex, attnum, rte, false);
2322 106 : appendStringInfoString(buf, " = ");
2323 106 : deparseExpr((Expr *) tle->expr, &context);
2324 : }
2325 :
2326 90 : reset_transmission_modes(nestlevel);
2327 :
2328 90 : if (foreignrel->reloptkind == RELOPT_JOINREL)
2329 : {
2330 8 : List *ignore_conds = NIL;
2331 :
2332 :
2333 8 : appendStringInfoString(buf, " FROM ");
2334 8 : deparseFromExprForRel(buf, root, foreignrel, true, rtindex,
2335 : &ignore_conds, &additional_conds, params_list);
2336 8 : remote_conds = list_concat(remote_conds, ignore_conds);
2337 : }
2338 :
2339 90 : appendWhereClause(remote_conds, additional_conds, &context);
2340 :
2341 90 : if (additional_conds != NIL)
2342 0 : list_free_deep(additional_conds);
2343 :
2344 90 : if (foreignrel->reloptkind == RELOPT_JOINREL)
2345 8 : deparseExplicitTargetList(returningList, true, retrieved_attrs,
2346 : &context);
2347 : else
2348 82 : deparseReturningList(buf, rte, rtindex, rel, false,
2349 : NIL, returningList, retrieved_attrs);
2350 90 : }
2351 :
2352 : /*
2353 : * deparse remote DELETE statement
2354 : *
2355 : * The statement text is appended to buf, and we also create an integer List
2356 : * of the columns being retrieved by RETURNING (if any), which is returned
2357 : * to *retrieved_attrs.
2358 : */
2359 : void
2360 32 : deparseDeleteSql(StringInfo buf, RangeTblEntry *rte,
2361 : Index rtindex, Relation rel,
2362 : List *returningList,
2363 : List **retrieved_attrs)
2364 : {
2365 32 : appendStringInfoString(buf, "DELETE FROM ");
2366 32 : deparseRelation(buf, rel);
2367 32 : appendStringInfoString(buf, " WHERE ctid = $1");
2368 :
2369 32 : deparseReturningList(buf, rte, rtindex, rel,
2370 32 : rel->trigdesc && rel->trigdesc->trig_delete_after_row,
2371 : NIL, returningList, retrieved_attrs);
2372 32 : }
2373 :
2374 : /*
2375 : * deparse remote DELETE statement
2376 : *
2377 : * 'buf' is the output buffer to append the statement to
2378 : * 'rtindex' is the RT index of the associated target relation
2379 : * 'rel' is the relation descriptor for the target relation
2380 : * 'foreignrel' is the RelOptInfo for the target relation or the join relation
2381 : * containing all base relations in the query
2382 : * 'remote_conds' is the qual clauses that must be evaluated remotely
2383 : * '*params_list' is an output list of exprs that will become remote Params
2384 : * 'returningList' is the RETURNING targetlist
2385 : * '*retrieved_attrs' is an output list of integers of columns being retrieved
2386 : * by RETURNING (if any)
2387 : */
2388 : void
2389 118 : deparseDirectDeleteSql(StringInfo buf, PlannerInfo *root,
2390 : Index rtindex, Relation rel,
2391 : RelOptInfo *foreignrel,
2392 : List *remote_conds,
2393 : List **params_list,
2394 : List *returningList,
2395 : List **retrieved_attrs)
2396 : {
2397 : deparse_expr_cxt context;
2398 118 : List *additional_conds = NIL;
2399 :
2400 : /* Set up context struct for recursion */
2401 118 : context.root = root;
2402 118 : context.foreignrel = foreignrel;
2403 118 : context.scanrel = foreignrel;
2404 118 : context.buf = buf;
2405 118 : context.params_list = params_list;
2406 :
2407 118 : appendStringInfoString(buf, "DELETE FROM ");
2408 118 : deparseRelation(buf, rel);
2409 118 : if (foreignrel->reloptkind == RELOPT_JOINREL)
2410 8 : appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, rtindex);
2411 :
2412 118 : if (foreignrel->reloptkind == RELOPT_JOINREL)
2413 : {
2414 8 : List *ignore_conds = NIL;
2415 :
2416 8 : appendStringInfoString(buf, " USING ");
2417 8 : deparseFromExprForRel(buf, root, foreignrel, true, rtindex,
2418 : &ignore_conds, &additional_conds, params_list);
2419 8 : remote_conds = list_concat(remote_conds, ignore_conds);
2420 : }
2421 :
2422 118 : appendWhereClause(remote_conds, additional_conds, &context);
2423 :
2424 118 : if (additional_conds != NIL)
2425 0 : list_free_deep(additional_conds);
2426 :
2427 118 : if (foreignrel->reloptkind == RELOPT_JOINREL)
2428 8 : deparseExplicitTargetList(returningList, true, retrieved_attrs,
2429 : &context);
2430 : else
2431 110 : deparseReturningList(buf, planner_rt_fetch(rtindex, root),
2432 : rtindex, rel, false,
2433 : NIL, returningList, retrieved_attrs);
2434 118 : }
2435 :
2436 : /*
2437 : * Add a RETURNING clause, if needed, to an INSERT/UPDATE/DELETE.
2438 : */
2439 : static void
2440 610 : deparseReturningList(StringInfo buf, RangeTblEntry *rte,
2441 : Index rtindex, Relation rel,
2442 : bool trig_after_row,
2443 : List *withCheckOptionList,
2444 : List *returningList,
2445 : List **retrieved_attrs)
2446 : {
2447 610 : Bitmapset *attrs_used = NULL;
2448 :
2449 610 : if (trig_after_row)
2450 : {
2451 : /* whole-row reference acquires all non-system columns */
2452 48 : attrs_used =
2453 48 : bms_make_singleton(0 - FirstLowInvalidHeapAttributeNumber);
2454 : }
2455 :
2456 610 : if (withCheckOptionList != NIL)
2457 : {
2458 : /*
2459 : * We need the attrs, non-system and system, mentioned in the local
2460 : * query's WITH CHECK OPTION list.
2461 : *
2462 : * Note: we do this to ensure that WCO constraints will be evaluated
2463 : * on the data actually inserted/updated on the remote side, which
2464 : * might differ from the data supplied by the core code, for example
2465 : * as a result of remote triggers.
2466 : */
2467 38 : pull_varattnos((Node *) withCheckOptionList, rtindex,
2468 : &attrs_used);
2469 : }
2470 :
2471 610 : if (returningList != NIL)
2472 : {
2473 : /*
2474 : * We need the attrs, non-system and system, mentioned in the local
2475 : * query's RETURNING list.
2476 : */
2477 140 : pull_varattnos((Node *) returningList, rtindex,
2478 : &attrs_used);
2479 : }
2480 :
2481 610 : if (attrs_used != NULL)
2482 224 : deparseTargetList(buf, rte, rtindex, rel, true, attrs_used, false,
2483 : retrieved_attrs);
2484 : else
2485 386 : *retrieved_attrs = NIL;
2486 610 : }
2487 :
2488 : /*
2489 : * Construct SELECT statement to acquire size in blocks of given relation.
2490 : *
2491 : * Note: we use local definition of block size, not remote definition.
2492 : * This is perhaps debatable.
2493 : *
2494 : * Note: pg_relation_size() exists in 8.1 and later.
2495 : */
2496 : void
2497 84 : deparseAnalyzeSizeSql(StringInfo buf, Relation rel)
2498 : {
2499 : StringInfoData relname;
2500 :
2501 : /* We'll need the remote relation name as a literal. */
2502 84 : initStringInfo(&relname);
2503 84 : deparseRelation(&relname, rel);
2504 :
2505 84 : appendStringInfoString(buf, "SELECT pg_catalog.pg_relation_size(");
2506 84 : deparseStringLiteral(buf, relname.data);
2507 84 : appendStringInfo(buf, "::pg_catalog.regclass) / %d", BLCKSZ);
2508 84 : }
2509 :
2510 : /*
2511 : * Construct SELECT statement to acquire the number of rows and the relkind of
2512 : * a relation.
2513 : *
2514 : * Note: we just return the remote server's reltuples value, which might
2515 : * be off a good deal, but it doesn't seem worth working harder. See
2516 : * comments in postgresAcquireSampleRowsFunc.
2517 : */
2518 : void
2519 84 : deparseAnalyzeInfoSql(StringInfo buf, Relation rel)
2520 : {
2521 : StringInfoData relname;
2522 :
2523 : /* We'll need the remote relation name as a literal. */
2524 84 : initStringInfo(&relname);
2525 84 : deparseRelation(&relname, rel);
2526 :
2527 84 : appendStringInfoString(buf, "SELECT reltuples, relkind FROM pg_catalog.pg_class WHERE oid = ");
2528 84 : deparseStringLiteral(buf, relname.data);
2529 84 : appendStringInfoString(buf, "::pg_catalog.regclass");
2530 84 : }
2531 :
2532 : /*
2533 : * Construct SELECT statement to acquire sample rows of given relation.
2534 : *
2535 : * SELECT command is appended to buf, and list of columns retrieved
2536 : * is returned to *retrieved_attrs.
2537 : *
2538 : * We only support sampling methods we can decide based on server version.
2539 : * Allowing custom TSM modules (like tsm_system_rows) might be useful, but it
2540 : * would require detecting which extensions are installed, to allow automatic
2541 : * fall-back. Moreover, the methods may use different parameters like number
2542 : * of rows (and not sampling rate). So we leave this for future improvements.
2543 : *
2544 : * Using random() to sample rows on the remote server has the advantage that
2545 : * this works on all PostgreSQL versions (unlike TABLESAMPLE), and that it
2546 : * does the sampling on the remote side (without transferring everything and
2547 : * then discarding most rows).
2548 : *
2549 : * The disadvantage is that we still have to read all rows and evaluate the
2550 : * random(), while TABLESAMPLE (at least with the "system" method) may skip.
2551 : * It's not that different from the "bernoulli" method, though.
2552 : *
2553 : * We could also do "ORDER BY random() LIMIT x", which would always pick
2554 : * the expected number of rows, but it requires sorting so it may be much
2555 : * more expensive (particularly on large tables, which is what the
2556 : * remote sampling is meant to improve).
2557 : */
2558 : void
2559 84 : deparseAnalyzeSql(StringInfo buf, Relation rel,
2560 : PgFdwSamplingMethod sample_method, double sample_frac,
2561 : List **retrieved_attrs)
2562 : {
2563 84 : Oid relid = RelationGetRelid(rel);
2564 84 : TupleDesc tupdesc = RelationGetDescr(rel);
2565 : int i;
2566 : char *colname;
2567 : List *options;
2568 : ListCell *lc;
2569 84 : bool first = true;
2570 :
2571 84 : *retrieved_attrs = NIL;
2572 :
2573 84 : appendStringInfoString(buf, "SELECT ");
2574 364 : for (i = 0; i < tupdesc->natts; i++)
2575 : {
2576 : /* Ignore dropped columns. */
2577 280 : if (TupleDescAttr(tupdesc, i)->attisdropped)
2578 6 : continue;
2579 :
2580 274 : if (!first)
2581 190 : appendStringInfoString(buf, ", ");
2582 274 : first = false;
2583 :
2584 : /* Use attribute name or column_name option. */
2585 274 : colname = NameStr(TupleDescAttr(tupdesc, i)->attname);
2586 274 : options = GetForeignColumnOptions(relid, i + 1);
2587 :
2588 274 : foreach(lc, options)
2589 : {
2590 6 : DefElem *def = (DefElem *) lfirst(lc);
2591 :
2592 6 : if (strcmp(def->defname, "column_name") == 0)
2593 : {
2594 6 : colname = defGetString(def);
2595 6 : break;
2596 : }
2597 : }
2598 :
2599 274 : appendStringInfoString(buf, quote_identifier(colname));
2600 :
2601 274 : *retrieved_attrs = lappend_int(*retrieved_attrs, i + 1);
2602 : }
2603 :
2604 : /* Don't generate bad syntax for zero-column relation. */
2605 84 : if (first)
2606 0 : appendStringInfoString(buf, "NULL");
2607 :
2608 : /*
2609 : * Construct FROM clause, and perhaps WHERE clause too, depending on the
2610 : * selected sampling method.
2611 : */
2612 84 : appendStringInfoString(buf, " FROM ");
2613 84 : deparseRelation(buf, rel);
2614 :
2615 84 : switch (sample_method)
2616 : {
2617 84 : case ANALYZE_SAMPLE_OFF:
2618 : /* nothing to do here */
2619 84 : break;
2620 :
2621 0 : case ANALYZE_SAMPLE_RANDOM:
2622 0 : appendStringInfo(buf, " WHERE pg_catalog.random() < %f", sample_frac);
2623 0 : break;
2624 :
2625 0 : case ANALYZE_SAMPLE_SYSTEM:
2626 0 : appendStringInfo(buf, " TABLESAMPLE SYSTEM(%f)", (100.0 * sample_frac));
2627 0 : break;
2628 :
2629 0 : case ANALYZE_SAMPLE_BERNOULLI:
2630 0 : appendStringInfo(buf, " TABLESAMPLE BERNOULLI(%f)", (100.0 * sample_frac));
2631 0 : break;
2632 :
2633 0 : case ANALYZE_SAMPLE_AUTO:
2634 : /* should have been resolved into actual method */
2635 0 : elog(ERROR, "unexpected sampling method");
2636 : break;
2637 : }
2638 84 : }
2639 :
2640 : /*
2641 : * Construct a simple "TRUNCATE rel" statement
2642 : */
2643 : void
2644 24 : deparseTruncateSql(StringInfo buf,
2645 : List *rels,
2646 : DropBehavior behavior,
2647 : bool restart_seqs)
2648 : {
2649 : ListCell *cell;
2650 :
2651 24 : appendStringInfoString(buf, "TRUNCATE ");
2652 :
2653 52 : foreach(cell, rels)
2654 : {
2655 28 : Relation rel = lfirst(cell);
2656 :
2657 28 : if (cell != list_head(rels))
2658 4 : appendStringInfoString(buf, ", ");
2659 :
2660 28 : deparseRelation(buf, rel);
2661 : }
2662 :
2663 24 : appendStringInfo(buf, " %s IDENTITY",
2664 : restart_seqs ? "RESTART" : "CONTINUE");
2665 :
2666 24 : if (behavior == DROP_RESTRICT)
2667 20 : appendStringInfoString(buf, " RESTRICT");
2668 4 : else if (behavior == DROP_CASCADE)
2669 4 : appendStringInfoString(buf, " CASCADE");
2670 24 : }
2671 :
2672 : /*
2673 : * Construct name to use for given column, and emit it into buf.
2674 : * If it has a column_name FDW option, use that instead of attribute name.
2675 : *
2676 : * If qualify_col is true, qualify column name with the alias of relation.
2677 : */
2678 : static void
2679 29022 : deparseColumnRef(StringInfo buf, int varno, int varattno, RangeTblEntry *rte,
2680 : bool qualify_col)
2681 : {
2682 : /* We support fetching the remote side's CTID and OID. */
2683 29022 : if (varattno == SelfItemPointerAttributeNumber)
2684 : {
2685 96 : if (qualify_col)
2686 92 : ADD_REL_QUALIFIER(buf, varno);
2687 96 : appendStringInfoString(buf, "ctid");
2688 : }
2689 28926 : else if (varattno < 0)
2690 : {
2691 : /*
2692 : * All other system attributes are fetched as 0, except for table OID,
2693 : * which is fetched as the local table OID. However, we must be
2694 : * careful; the table could be beneath an outer join, in which case it
2695 : * must go to NULL whenever the rest of the row does.
2696 : */
2697 0 : Oid fetchval = 0;
2698 :
2699 0 : if (varattno == TableOidAttributeNumber)
2700 0 : fetchval = rte->relid;
2701 :
2702 0 : if (qualify_col)
2703 : {
2704 0 : appendStringInfoString(buf, "CASE WHEN (");
2705 0 : ADD_REL_QUALIFIER(buf, varno);
2706 0 : appendStringInfo(buf, "*)::text IS NOT NULL THEN %u END", fetchval);
2707 : }
2708 : else
2709 0 : appendStringInfo(buf, "%u", fetchval);
2710 : }
2711 28926 : else if (varattno == 0)
2712 : {
2713 : /* Whole row reference */
2714 : Relation rel;
2715 : Bitmapset *attrs_used;
2716 :
2717 : /* Required only to be passed down to deparseTargetList(). */
2718 : List *retrieved_attrs;
2719 :
2720 : /*
2721 : * The lock on the relation will be held by upper callers, so it's
2722 : * fine to open it with no lock here.
2723 : */
2724 464 : rel = table_open(rte->relid, NoLock);
2725 :
2726 : /*
2727 : * The local name of the foreign table can not be recognized by the
2728 : * foreign server and the table it references on foreign server might
2729 : * have different column ordering or different columns than those
2730 : * declared locally. Hence we have to deparse whole-row reference as
2731 : * ROW(columns referenced locally). Construct this by deparsing a
2732 : * "whole row" attribute.
2733 : */
2734 464 : attrs_used = bms_add_member(NULL,
2735 : 0 - FirstLowInvalidHeapAttributeNumber);
2736 :
2737 : /*
2738 : * In case the whole-row reference is under an outer join then it has
2739 : * to go NULL whenever the rest of the row goes NULL. Deparsing a join
2740 : * query would always involve multiple relations, thus qualify_col
2741 : * would be true.
2742 : */
2743 464 : if (qualify_col)
2744 : {
2745 456 : appendStringInfoString(buf, "CASE WHEN (");
2746 456 : ADD_REL_QUALIFIER(buf, varno);
2747 456 : appendStringInfoString(buf, "*)::text IS NOT NULL THEN ");
2748 : }
2749 :
2750 464 : appendStringInfoString(buf, "ROW(");
2751 464 : deparseTargetList(buf, rte, varno, rel, false, attrs_used, qualify_col,
2752 : &retrieved_attrs);
2753 464 : appendStringInfoChar(buf, ')');
2754 :
2755 : /* Complete the CASE WHEN statement started above. */
2756 464 : if (qualify_col)
2757 456 : appendStringInfoString(buf, " END");
2758 :
2759 464 : table_close(rel, NoLock);
2760 464 : bms_free(attrs_used);
2761 : }
2762 : else
2763 : {
2764 28462 : char *colname = NULL;
2765 : List *options;
2766 : ListCell *lc;
2767 :
2768 : /* varno must not be any of OUTER_VAR, INNER_VAR and INDEX_VAR. */
2769 : Assert(!IS_SPECIAL_VARNO(varno));
2770 :
2771 : /*
2772 : * If it's a column of a foreign table, and it has the column_name FDW
2773 : * option, use that value.
2774 : */
2775 28462 : options = GetForeignColumnOptions(rte->relid, varattno);
2776 28462 : foreach(lc, options)
2777 : {
2778 6562 : DefElem *def = (DefElem *) lfirst(lc);
2779 :
2780 6562 : if (strcmp(def->defname, "column_name") == 0)
2781 : {
2782 6562 : colname = defGetString(def);
2783 6562 : break;
2784 : }
2785 : }
2786 :
2787 : /*
2788 : * If it's a column of a regular table or it doesn't have column_name
2789 : * FDW option, use attribute name.
2790 : */
2791 28462 : if (colname == NULL)
2792 21900 : colname = get_attname(rte->relid, varattno, false);
2793 :
2794 28462 : if (qualify_col)
2795 14568 : ADD_REL_QUALIFIER(buf, varno);
2796 :
2797 28462 : appendStringInfoString(buf, quote_identifier(colname));
2798 : }
2799 29022 : }
2800 :
2801 : /*
2802 : * Append remote name of specified foreign table to buf.
2803 : * Use value of table_name FDW option (if any) instead of relation's name.
2804 : * Similarly, schema_name FDW option overrides schema name.
2805 : */
2806 : static void
2807 7068 : deparseRelation(StringInfo buf, Relation rel)
2808 : {
2809 : ForeignTable *table;
2810 7068 : const char *nspname = NULL;
2811 7068 : const char *relname = NULL;
2812 : ListCell *lc;
2813 :
2814 : /* obtain additional catalog information. */
2815 7068 : table = GetForeignTable(RelationGetRelid(rel));
2816 :
2817 : /*
2818 : * Use value of FDW options if any, instead of the name of object itself.
2819 : */
2820 23084 : foreach(lc, table->options)
2821 : {
2822 16016 : DefElem *def = (DefElem *) lfirst(lc);
2823 :
2824 16016 : if (strcmp(def->defname, "schema_name") == 0)
2825 4848 : nspname = defGetString(def);
2826 11168 : else if (strcmp(def->defname, "table_name") == 0)
2827 7068 : relname = defGetString(def);
2828 : }
2829 :
2830 : /*
2831 : * Note: we could skip printing the schema name if it's pg_catalog, but
2832 : * that doesn't seem worth the trouble.
2833 : */
2834 7068 : if (nspname == NULL)
2835 2220 : nspname = get_namespace_name(RelationGetNamespace(rel));
2836 7068 : if (relname == NULL)
2837 0 : relname = RelationGetRelationName(rel);
2838 :
2839 7068 : appendStringInfo(buf, "%s.%s",
2840 : quote_identifier(nspname), quote_identifier(relname));
2841 7068 : }
2842 :
2843 : /*
2844 : * Append a SQL string literal representing "val" to buf.
2845 : */
2846 : void
2847 652 : deparseStringLiteral(StringInfo buf, const char *val)
2848 : {
2849 : const char *valptr;
2850 :
2851 : /*
2852 : * Rather than making assumptions about the remote server's value of
2853 : * standard_conforming_strings, always use E'foo' syntax if there are any
2854 : * backslashes. This will fail on remote servers before 8.1, but those
2855 : * are long out of support.
2856 : */
2857 652 : if (strchr(val, '\\') != NULL)
2858 2 : appendStringInfoChar(buf, ESCAPE_STRING_SYNTAX);
2859 652 : appendStringInfoChar(buf, '\'');
2860 5956 : for (valptr = val; *valptr; valptr++)
2861 : {
2862 5304 : char ch = *valptr;
2863 :
2864 5304 : if (SQL_STR_DOUBLE(ch, true))
2865 4 : appendStringInfoChar(buf, ch);
2866 5304 : appendStringInfoChar(buf, ch);
2867 : }
2868 652 : appendStringInfoChar(buf, '\'');
2869 652 : }
2870 :
2871 : /*
2872 : * Deparse given expression into context->buf.
2873 : *
2874 : * This function must support all the same node types that foreign_expr_walker
2875 : * accepts.
2876 : *
2877 : * Note: unlike ruleutils.c, we just use a simple hard-wired parenthesization
2878 : * scheme: anything more complex than a Var, Const, function call or cast
2879 : * should be self-parenthesized.
2880 : */
2881 : static void
2882 23660 : deparseExpr(Expr *node, deparse_expr_cxt *context)
2883 : {
2884 23660 : if (node == NULL)
2885 0 : return;
2886 :
2887 23660 : switch (nodeTag(node))
2888 : {
2889 16370 : case T_Var:
2890 16370 : deparseVar((Var *) node, context);
2891 16370 : break;
2892 1142 : case T_Const:
2893 1142 : deparseConst((Const *) node, context, 0);
2894 1142 : break;
2895 56 : case T_Param:
2896 56 : deparseParam((Param *) node, context);
2897 56 : break;
2898 2 : case T_SubscriptingRef:
2899 2 : deparseSubscriptingRef((SubscriptingRef *) node, context);
2900 2 : break;
2901 116 : case T_FuncExpr:
2902 116 : deparseFuncExpr((FuncExpr *) node, context);
2903 116 : break;
2904 5198 : case T_OpExpr:
2905 5198 : deparseOpExpr((OpExpr *) node, context);
2906 5198 : break;
2907 2 : case T_DistinctExpr:
2908 2 : deparseDistinctExpr((DistinctExpr *) node, context);
2909 2 : break;
2910 8 : case T_ScalarArrayOpExpr:
2911 8 : deparseScalarArrayOpExpr((ScalarArrayOpExpr *) node, context);
2912 8 : break;
2913 66 : case T_RelabelType:
2914 66 : deparseRelabelType((RelabelType *) node, context);
2915 66 : break;
2916 76 : case T_BoolExpr:
2917 76 : deparseBoolExpr((BoolExpr *) node, context);
2918 76 : break;
2919 56 : case T_NullTest:
2920 56 : deparseNullTest((NullTest *) node, context);
2921 56 : break;
2922 42 : case T_CaseExpr:
2923 42 : deparseCaseExpr((CaseExpr *) node, context);
2924 42 : break;
2925 8 : case T_ArrayExpr:
2926 8 : deparseArrayExpr((ArrayExpr *) node, context);
2927 8 : break;
2928 518 : case T_Aggref:
2929 518 : deparseAggref((Aggref *) node, context);
2930 518 : break;
2931 0 : default:
2932 0 : elog(ERROR, "unsupported expression type for deparse: %d",
2933 : (int) nodeTag(node));
2934 : break;
2935 : }
2936 : }
2937 :
2938 : /*
2939 : * Deparse given Var node into context->buf.
2940 : *
2941 : * If the Var belongs to the foreign relation, just print its remote name.
2942 : * Otherwise, it's effectively a Param (and will in fact be a Param at
2943 : * run time). Handle it the same way we handle plain Params --- see
2944 : * deparseParam for comments.
2945 : */
2946 : static void
2947 16370 : deparseVar(Var *node, deparse_expr_cxt *context)
2948 : {
2949 16370 : Relids relids = context->scanrel->relids;
2950 : int relno;
2951 : int colno;
2952 :
2953 : /* Qualify columns when multiple relations are involved. */
2954 16370 : bool qualify_col = (bms_membership(relids) == BMS_MULTIPLE);
2955 :
2956 : /*
2957 : * If the Var belongs to the foreign relation that is deparsed as a
2958 : * subquery, use the relation and column alias to the Var provided by the
2959 : * subquery, instead of the remote name.
2960 : */
2961 16370 : if (is_subquery_var(node, context->scanrel, &relno, &colno))
2962 : {
2963 232 : appendStringInfo(context->buf, "%s%d.%s%d",
2964 : SUBQUERY_REL_ALIAS_PREFIX, relno,
2965 : SUBQUERY_COL_ALIAS_PREFIX, colno);
2966 232 : return;
2967 : }
2968 :
2969 16138 : if (bms_is_member(node->varno, relids) && node->varlevelsup == 0)
2970 15728 : deparseColumnRef(context->buf, node->varno, node->varattno,
2971 15728 : planner_rt_fetch(node->varno, context->root),
2972 : qualify_col);
2973 : else
2974 : {
2975 : /* Treat like a Param */
2976 410 : if (context->params_list)
2977 : {
2978 22 : int pindex = 0;
2979 : ListCell *lc;
2980 :
2981 : /* find its index in params_list */
2982 22 : foreach(lc, *context->params_list)
2983 : {
2984 0 : pindex++;
2985 0 : if (equal(node, (Node *) lfirst(lc)))
2986 0 : break;
2987 : }
2988 22 : if (lc == NULL)
2989 : {
2990 : /* not in list, so add it */
2991 22 : pindex++;
2992 22 : *context->params_list = lappend(*context->params_list, node);
2993 : }
2994 :
2995 22 : printRemoteParam(pindex, node->vartype, node->vartypmod, context);
2996 : }
2997 : else
2998 : {
2999 388 : printRemotePlaceholder(node->vartype, node->vartypmod, context);
3000 : }
3001 : }
3002 : }
3003 :
3004 : /*
3005 : * Deparse given constant value into context->buf.
3006 : *
3007 : * This function has to be kept in sync with ruleutils.c's get_const_expr.
3008 : *
3009 : * As in that function, showtype can be -1 to never show "::typename"
3010 : * decoration, +1 to always show it, or 0 to show it only if the constant
3011 : * wouldn't be assumed to be the right type by default.
3012 : *
3013 : * In addition, this code allows showtype to be -2 to indicate that we should
3014 : * not show "::typename" decoration if the constant is printed as an untyped
3015 : * literal or NULL (while in other cases, behaving as for showtype == 0).
3016 : */
3017 : static void
3018 3526 : deparseConst(Const *node, deparse_expr_cxt *context, int showtype)
3019 : {
3020 3526 : StringInfo buf = context->buf;
3021 : Oid typoutput;
3022 : bool typIsVarlena;
3023 : char *extval;
3024 3526 : bool isfloat = false;
3025 3526 : bool isstring = false;
3026 : bool needlabel;
3027 :
3028 3526 : if (node->constisnull)
3029 : {
3030 38 : appendStringInfoString(buf, "NULL");
3031 38 : if (showtype >= 0)
3032 38 : appendStringInfo(buf, "::%s",
3033 : deparse_type_name(node->consttype,
3034 : node->consttypmod));
3035 38 : return;
3036 : }
3037 :
3038 3488 : getTypeOutputInfo(node->consttype,
3039 : &typoutput, &typIsVarlena);
3040 3488 : extval = OidOutputFunctionCall(typoutput, node->constvalue);
3041 :
3042 3488 : switch (node->consttype)
3043 : {
3044 3322 : case INT2OID:
3045 : case INT4OID:
3046 : case INT8OID:
3047 : case OIDOID:
3048 : case FLOAT4OID:
3049 : case FLOAT8OID:
3050 : case NUMERICOID:
3051 : {
3052 : /*
3053 : * No need to quote unless it's a special value such as 'NaN'.
3054 : * See comments in get_const_expr().
3055 : */
3056 3322 : if (strspn(extval, "0123456789+-eE.") == strlen(extval))
3057 : {
3058 3322 : if (extval[0] == '+' || extval[0] == '-')
3059 2 : appendStringInfo(buf, "(%s)", extval);
3060 : else
3061 3320 : appendStringInfoString(buf, extval);
3062 3322 : if (strcspn(extval, "eE.") != strlen(extval))
3063 4 : isfloat = true; /* it looks like a float */
3064 : }
3065 : else
3066 0 : appendStringInfo(buf, "'%s'", extval);
3067 : }
3068 3322 : break;
3069 0 : case BITOID:
3070 : case VARBITOID:
3071 0 : appendStringInfo(buf, "B'%s'", extval);
3072 0 : break;
3073 4 : case BOOLOID:
3074 4 : if (strcmp(extval, "t") == 0)
3075 4 : appendStringInfoString(buf, "true");
3076 : else
3077 0 : appendStringInfoString(buf, "false");
3078 4 : break;
3079 162 : default:
3080 162 : deparseStringLiteral(buf, extval);
3081 162 : isstring = true;
3082 162 : break;
3083 : }
3084 :
3085 3488 : pfree(extval);
3086 :
3087 3488 : if (showtype == -1)
3088 0 : return; /* never print type label */
3089 :
3090 : /*
3091 : * For showtype == 0, append ::typename unless the constant will be
3092 : * implicitly typed as the right type when it is read in.
3093 : *
3094 : * XXX this code has to be kept in sync with the behavior of the parser,
3095 : * especially make_const.
3096 : */
3097 3488 : switch (node->consttype)
3098 : {
3099 2846 : case BOOLOID:
3100 : case INT4OID:
3101 : case UNKNOWNOID:
3102 2846 : needlabel = false;
3103 2846 : break;
3104 42 : case NUMERICOID:
3105 42 : needlabel = !isfloat || (node->consttypmod >= 0);
3106 42 : break;
3107 600 : default:
3108 600 : if (showtype == -2)
3109 : {
3110 : /* label unless we printed it as an untyped string */
3111 86 : needlabel = !isstring;
3112 : }
3113 : else
3114 514 : needlabel = true;
3115 600 : break;
3116 : }
3117 3488 : if (needlabel || showtype > 0)
3118 552 : appendStringInfo(buf, "::%s",
3119 : deparse_type_name(node->consttype,
3120 : node->consttypmod));
3121 : }
3122 :
3123 : /*
3124 : * Deparse given Param node.
3125 : *
3126 : * If we're generating the query "for real", add the Param to
3127 : * context->params_list if it's not already present, and then use its index
3128 : * in that list as the remote parameter number. During EXPLAIN, there's
3129 : * no need to identify a parameter number.
3130 : */
3131 : static void
3132 56 : deparseParam(Param *node, deparse_expr_cxt *context)
3133 : {
3134 56 : if (context->params_list)
3135 : {
3136 36 : int pindex = 0;
3137 : ListCell *lc;
3138 :
3139 : /* find its index in params_list */
3140 40 : foreach(lc, *context->params_list)
3141 : {
3142 4 : pindex++;
3143 4 : if (equal(node, (Node *) lfirst(lc)))
3144 0 : break;
3145 : }
3146 36 : if (lc == NULL)
3147 : {
3148 : /* not in list, so add it */
3149 36 : pindex++;
3150 36 : *context->params_list = lappend(*context->params_list, node);
3151 : }
3152 :
3153 36 : printRemoteParam(pindex, node->paramtype, node->paramtypmod, context);
3154 : }
3155 : else
3156 : {
3157 20 : printRemotePlaceholder(node->paramtype, node->paramtypmod, context);
3158 : }
3159 56 : }
3160 :
3161 : /*
3162 : * Deparse a container subscript expression.
3163 : */
3164 : static void
3165 2 : deparseSubscriptingRef(SubscriptingRef *node, deparse_expr_cxt *context)
3166 : {
3167 2 : StringInfo buf = context->buf;
3168 : ListCell *lowlist_item;
3169 : ListCell *uplist_item;
3170 :
3171 : /* Always parenthesize the expression. */
3172 2 : appendStringInfoChar(buf, '(');
3173 :
3174 : /*
3175 : * Deparse referenced array expression first. If that expression includes
3176 : * a cast, we have to parenthesize to prevent the array subscript from
3177 : * being taken as typename decoration. We can avoid that in the typical
3178 : * case of subscripting a Var, but otherwise do it.
3179 : */
3180 2 : if (IsA(node->refexpr, Var))
3181 0 : deparseExpr(node->refexpr, context);
3182 : else
3183 : {
3184 2 : appendStringInfoChar(buf, '(');
3185 2 : deparseExpr(node->refexpr, context);
3186 2 : appendStringInfoChar(buf, ')');
3187 : }
3188 :
3189 : /* Deparse subscript expressions. */
3190 2 : lowlist_item = list_head(node->reflowerindexpr); /* could be NULL */
3191 4 : foreach(uplist_item, node->refupperindexpr)
3192 : {
3193 2 : appendStringInfoChar(buf, '[');
3194 2 : if (lowlist_item)
3195 : {
3196 0 : deparseExpr(lfirst(lowlist_item), context);
3197 0 : appendStringInfoChar(buf, ':');
3198 0 : lowlist_item = lnext(node->reflowerindexpr, lowlist_item);
3199 : }
3200 2 : deparseExpr(lfirst(uplist_item), context);
3201 2 : appendStringInfoChar(buf, ']');
3202 : }
3203 :
3204 2 : appendStringInfoChar(buf, ')');
3205 2 : }
3206 :
3207 : /*
3208 : * Deparse a function call.
3209 : */
3210 : static void
3211 116 : deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context)
3212 : {
3213 116 : StringInfo buf = context->buf;
3214 : bool use_variadic;
3215 : bool first;
3216 : ListCell *arg;
3217 :
3218 : /*
3219 : * If the function call came from an implicit coercion, then just show the
3220 : * first argument.
3221 : */
3222 116 : if (node->funcformat == COERCE_IMPLICIT_CAST)
3223 : {
3224 42 : deparseExpr((Expr *) linitial(node->args), context);
3225 42 : return;
3226 : }
3227 :
3228 : /*
3229 : * If the function call came from a cast, then show the first argument
3230 : * plus an explicit cast operation.
3231 : */
3232 74 : if (node->funcformat == COERCE_EXPLICIT_CAST)
3233 : {
3234 0 : Oid rettype = node->funcresulttype;
3235 : int32 coercedTypmod;
3236 :
3237 : /* Get the typmod if this is a length-coercion function */
3238 0 : (void) exprIsLengthCoercion((Node *) node, &coercedTypmod);
3239 :
3240 0 : deparseExpr((Expr *) linitial(node->args), context);
3241 0 : appendStringInfo(buf, "::%s",
3242 : deparse_type_name(rettype, coercedTypmod));
3243 0 : return;
3244 : }
3245 :
3246 : /* Check if need to print VARIADIC (cf. ruleutils.c) */
3247 74 : use_variadic = node->funcvariadic;
3248 :
3249 : /*
3250 : * Normal function: display as proname(args).
3251 : */
3252 74 : appendFunctionName(node->funcid, context);
3253 74 : appendStringInfoChar(buf, '(');
3254 :
3255 : /* ... and all the arguments */
3256 74 : first = true;
3257 156 : foreach(arg, node->args)
3258 : {
3259 82 : if (!first)
3260 8 : appendStringInfoString(buf, ", ");
3261 82 : if (use_variadic && lnext(node->args, arg) == NULL)
3262 0 : appendStringInfoString(buf, "VARIADIC ");
3263 82 : deparseExpr((Expr *) lfirst(arg), context);
3264 82 : first = false;
3265 : }
3266 74 : appendStringInfoChar(buf, ')');
3267 : }
3268 :
3269 : /*
3270 : * Deparse given operator expression. To avoid problems around
3271 : * priority of operations, we always parenthesize the arguments.
3272 : */
3273 : static void
3274 5198 : deparseOpExpr(OpExpr *node, deparse_expr_cxt *context)
3275 : {
3276 5198 : StringInfo buf = context->buf;
3277 : HeapTuple tuple;
3278 : Form_pg_operator form;
3279 : Expr *right;
3280 5198 : bool canSuppressRightConstCast = false;
3281 : char oprkind;
3282 :
3283 : /* Retrieve information about the operator from system catalog. */
3284 5198 : tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(node->opno));
3285 5198 : if (!HeapTupleIsValid(tuple))
3286 0 : elog(ERROR, "cache lookup failed for operator %u", node->opno);
3287 5198 : form = (Form_pg_operator) GETSTRUCT(tuple);
3288 5198 : oprkind = form->oprkind;
3289 :
3290 : /* Sanity check. */
3291 : Assert((oprkind == 'l' && list_length(node->args) == 1) ||
3292 : (oprkind == 'b' && list_length(node->args) == 2));
3293 :
3294 5198 : right = llast(node->args);
3295 :
3296 : /* Always parenthesize the expression. */
3297 5198 : appendStringInfoChar(buf, '(');
3298 :
3299 : /* Deparse left operand, if any. */
3300 5198 : if (oprkind == 'b')
3301 : {
3302 5192 : Expr *left = linitial(node->args);
3303 5192 : Oid leftType = exprType((Node *) left);
3304 5192 : Oid rightType = exprType((Node *) right);
3305 5192 : bool canSuppressLeftConstCast = false;
3306 :
3307 : /*
3308 : * When considering a binary operator, if one operand is a Const that
3309 : * can be printed as a bare string literal or NULL (i.e., it will look
3310 : * like type UNKNOWN to the remote parser), the Const normally
3311 : * receives an explicit cast to the operator's input type. However,
3312 : * in Const-to-Var comparisons where both operands are of the same
3313 : * type, we prefer to suppress the explicit cast, leaving the Const's
3314 : * type resolution up to the remote parser. The remote's resolution
3315 : * heuristic will assume that an unknown input type being compared to
3316 : * a known input type is of that known type as well.
3317 : *
3318 : * This hack allows some cases to succeed where a remote column is
3319 : * declared with a different type in the local (foreign) table. By
3320 : * emitting "foreigncol = 'foo'" not "foreigncol = 'foo'::text" or the
3321 : * like, we allow the remote parser to pick an "=" operator that's
3322 : * compatible with whatever type the remote column really is, such as
3323 : * an enum.
3324 : *
3325 : * We allow cast suppression to happen only when the other operand is
3326 : * a plain foreign Var. Although the remote's unknown-type heuristic
3327 : * would apply to other cases just as well, we would be taking a
3328 : * bigger risk that the inferred type is something unexpected. With
3329 : * this restriction, if anything goes wrong it's the user's fault for
3330 : * not declaring the local column with the same type as the remote
3331 : * column.
3332 : */
3333 5192 : if (leftType == rightType)
3334 : {
3335 5160 : if (IsA(left, Const))
3336 6 : canSuppressLeftConstCast = isPlainForeignVar(right, context);
3337 5154 : else if (IsA(right, Const))
3338 2878 : canSuppressRightConstCast = isPlainForeignVar(left, context);
3339 : }
3340 :
3341 5192 : if (canSuppressLeftConstCast)
3342 4 : deparseConst((Const *) left, context, -2);
3343 : else
3344 5188 : deparseExpr(left, context);
3345 :
3346 5192 : appendStringInfoChar(buf, ' ');
3347 : }
3348 :
3349 : /* Deparse operator name. */
3350 5198 : deparseOperatorName(buf, form);
3351 :
3352 : /* Deparse right operand. */
3353 5198 : appendStringInfoChar(buf, ' ');
3354 :
3355 5198 : if (canSuppressRightConstCast)
3356 2380 : deparseConst((Const *) right, context, -2);
3357 : else
3358 2818 : deparseExpr(right, context);
3359 :
3360 5198 : appendStringInfoChar(buf, ')');
3361 :
3362 5198 : ReleaseSysCache(tuple);
3363 5198 : }
3364 :
3365 : /*
3366 : * Will "node" deparse as a plain foreign Var?
3367 : */
3368 : static bool
3369 2884 : isPlainForeignVar(Expr *node, deparse_expr_cxt *context)
3370 : {
3371 : /*
3372 : * We allow the foreign Var to have an implicit RelabelType, mainly so
3373 : * that this'll work with varchar columns. Note that deparseRelabelType
3374 : * will not print such a cast, so we're not breaking the restriction that
3375 : * the expression print as a plain Var. We won't risk it for an implicit
3376 : * cast that requires a function, nor for non-implicit RelabelType; such
3377 : * cases seem too likely to involve semantics changes compared to what
3378 : * would happen on the remote side.
3379 : */
3380 2884 : if (IsA(node, RelabelType) &&
3381 10 : ((RelabelType *) node)->relabelformat == COERCE_IMPLICIT_CAST)
3382 10 : node = ((RelabelType *) node)->arg;
3383 :
3384 2884 : if (IsA(node, Var))
3385 : {
3386 : /*
3387 : * The Var must be one that'll deparse as a foreign column reference
3388 : * (cf. deparseVar).
3389 : */
3390 2384 : Var *var = (Var *) node;
3391 2384 : Relids relids = context->scanrel->relids;
3392 :
3393 2384 : if (bms_is_member(var->varno, relids) && var->varlevelsup == 0)
3394 2384 : return true;
3395 : }
3396 :
3397 500 : return false;
3398 : }
3399 :
3400 : /*
3401 : * Print the name of an operator.
3402 : */
3403 : static void
3404 5222 : deparseOperatorName(StringInfo buf, Form_pg_operator opform)
3405 : {
3406 : char *opname;
3407 :
3408 : /* opname is not a SQL identifier, so we should not quote it. */
3409 5222 : opname = NameStr(opform->oprname);
3410 :
3411 : /* Print schema name only if it's not pg_catalog */
3412 5222 : if (opform->oprnamespace != PG_CATALOG_NAMESPACE)
3413 : {
3414 : const char *opnspname;
3415 :
3416 26 : opnspname = get_namespace_name(opform->oprnamespace);
3417 : /* Print fully qualified operator name. */
3418 26 : appendStringInfo(buf, "OPERATOR(%s.%s)",
3419 : quote_identifier(opnspname), opname);
3420 : }
3421 : else
3422 : {
3423 : /* Just print operator name. */
3424 5196 : appendStringInfoString(buf, opname);
3425 : }
3426 5222 : }
3427 :
3428 : /*
3429 : * Deparse IS DISTINCT FROM.
3430 : */
3431 : static void
3432 2 : deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context)
3433 : {
3434 2 : StringInfo buf = context->buf;
3435 :
3436 : Assert(list_length(node->args) == 2);
3437 :
3438 2 : appendStringInfoChar(buf, '(');
3439 2 : deparseExpr(linitial(node->args), context);
3440 2 : appendStringInfoString(buf, " IS DISTINCT FROM ");
3441 2 : deparseExpr(lsecond(node->args), context);
3442 2 : appendStringInfoChar(buf, ')');
3443 2 : }
3444 :
3445 : /*
3446 : * Deparse given ScalarArrayOpExpr expression. To avoid problems
3447 : * around priority of operations, we always parenthesize the arguments.
3448 : */
3449 : static void
3450 8 : deparseScalarArrayOpExpr(ScalarArrayOpExpr *node, deparse_expr_cxt *context)
3451 : {
3452 8 : StringInfo buf = context->buf;
3453 : HeapTuple tuple;
3454 : Form_pg_operator form;
3455 : Expr *arg1;
3456 : Expr *arg2;
3457 :
3458 : /* Retrieve information about the operator from system catalog. */
3459 8 : tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(node->opno));
3460 8 : if (!HeapTupleIsValid(tuple))
3461 0 : elog(ERROR, "cache lookup failed for operator %u", node->opno);
3462 8 : form = (Form_pg_operator) GETSTRUCT(tuple);
3463 :
3464 : /* Sanity check. */
3465 : Assert(list_length(node->args) == 2);
3466 :
3467 : /* Always parenthesize the expression. */
3468 8 : appendStringInfoChar(buf, '(');
3469 :
3470 : /* Deparse left operand. */
3471 8 : arg1 = linitial(node->args);
3472 8 : deparseExpr(arg1, context);
3473 8 : appendStringInfoChar(buf, ' ');
3474 :
3475 : /* Deparse operator name plus decoration. */
3476 8 : deparseOperatorName(buf, form);
3477 8 : appendStringInfo(buf, " %s (", node->useOr ? "ANY" : "ALL");
3478 :
3479 : /* Deparse right operand. */
3480 8 : arg2 = lsecond(node->args);
3481 8 : deparseExpr(arg2, context);
3482 :
3483 8 : appendStringInfoChar(buf, ')');
3484 :
3485 : /* Always parenthesize the expression. */
3486 8 : appendStringInfoChar(buf, ')');
3487 :
3488 8 : ReleaseSysCache(tuple);
3489 8 : }
3490 :
3491 : /*
3492 : * Deparse a RelabelType (binary-compatible cast) node.
3493 : */
3494 : static void
3495 66 : deparseRelabelType(RelabelType *node, deparse_expr_cxt *context)
3496 : {
3497 66 : deparseExpr(node->arg, context);
3498 66 : if (node->relabelformat != COERCE_IMPLICIT_CAST)
3499 0 : appendStringInfo(context->buf, "::%s",
3500 : deparse_type_name(node->resulttype,
3501 : node->resulttypmod));
3502 66 : }
3503 :
3504 : /*
3505 : * Deparse a BoolExpr node.
3506 : */
3507 : static void
3508 76 : deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context)
3509 : {
3510 76 : StringInfo buf = context->buf;
3511 76 : const char *op = NULL; /* keep compiler quiet */
3512 : bool first;
3513 : ListCell *lc;
3514 :
3515 76 : switch (node->boolop)
3516 : {
3517 36 : case AND_EXPR:
3518 36 : op = "AND";
3519 36 : break;
3520 40 : case OR_EXPR:
3521 40 : op = "OR";
3522 40 : break;
3523 0 : case NOT_EXPR:
3524 0 : appendStringInfoString(buf, "(NOT ");
3525 0 : deparseExpr(linitial(node->args), context);
3526 0 : appendStringInfoChar(buf, ')');
3527 0 : return;
3528 : }
3529 :
3530 76 : appendStringInfoChar(buf, '(');
3531 76 : first = true;
3532 228 : foreach(lc, node->args)
3533 : {
3534 152 : if (!first)
3535 76 : appendStringInfo(buf, " %s ", op);
3536 152 : deparseExpr((Expr *) lfirst(lc), context);
3537 152 : first = false;
3538 : }
3539 76 : appendStringInfoChar(buf, ')');
3540 : }
3541 :
3542 : /*
3543 : * Deparse IS [NOT] NULL expression.
3544 : */
3545 : static void
3546 56 : deparseNullTest(NullTest *node, deparse_expr_cxt *context)
3547 : {
3548 56 : StringInfo buf = context->buf;
3549 :
3550 56 : appendStringInfoChar(buf, '(');
3551 56 : deparseExpr(node->arg, context);
3552 :
3553 : /*
3554 : * For scalar inputs, we prefer to print as IS [NOT] NULL, which is
3555 : * shorter and traditional. If it's a rowtype input but we're applying a
3556 : * scalar test, must print IS [NOT] DISTINCT FROM NULL to be semantically
3557 : * correct.
3558 : */
3559 56 : if (node->argisrow || !type_is_rowtype(exprType((Node *) node->arg)))
3560 : {
3561 56 : if (node->nulltesttype == IS_NULL)
3562 38 : appendStringInfoString(buf, " IS NULL)");
3563 : else
3564 18 : appendStringInfoString(buf, " IS NOT NULL)");
3565 : }
3566 : else
3567 : {
3568 0 : if (node->nulltesttype == IS_NULL)
3569 0 : appendStringInfoString(buf, " IS NOT DISTINCT FROM NULL)");
3570 : else
3571 0 : appendStringInfoString(buf, " IS DISTINCT FROM NULL)");
3572 : }
3573 56 : }
3574 :
3575 : /*
3576 : * Deparse CASE expression
3577 : */
3578 : static void
3579 42 : deparseCaseExpr(CaseExpr *node, deparse_expr_cxt *context)
3580 : {
3581 42 : StringInfo buf = context->buf;
3582 : ListCell *lc;
3583 :
3584 42 : appendStringInfoString(buf, "(CASE");
3585 :
3586 : /* If this is a CASE arg WHEN then emit the arg expression */
3587 42 : if (node->arg != NULL)
3588 : {
3589 18 : appendStringInfoChar(buf, ' ');
3590 18 : deparseExpr(node->arg, context);
3591 : }
3592 :
3593 : /* Add each condition/result of the CASE clause */
3594 98 : foreach(lc, node->args)
3595 : {
3596 56 : CaseWhen *whenclause = (CaseWhen *) lfirst(lc);
3597 :
3598 : /* WHEN */
3599 56 : appendStringInfoString(buf, " WHEN ");
3600 56 : if (node->arg == NULL) /* CASE WHEN */
3601 24 : deparseExpr(whenclause->expr, context);
3602 : else /* CASE arg WHEN */
3603 : {
3604 : /* Ignore the CaseTestExpr and equality operator. */
3605 32 : deparseExpr(lsecond(castNode(OpExpr, whenclause->expr)->args),
3606 : context);
3607 : }
3608 :
3609 : /* THEN */
3610 56 : appendStringInfoString(buf, " THEN ");
3611 56 : deparseExpr(whenclause->result, context);
3612 : }
3613 :
3614 : /* add ELSE if present */
3615 42 : if (node->defresult != NULL)
3616 : {
3617 42 : appendStringInfoString(buf, " ELSE ");
3618 42 : deparseExpr(node->defresult, context);
3619 : }
3620 :
3621 : /* append END */
3622 42 : appendStringInfoString(buf, " END)");
3623 42 : }
3624 :
3625 : /*
3626 : * Deparse ARRAY[...] construct.
3627 : */
3628 : static void
3629 8 : deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context)
3630 : {
3631 8 : StringInfo buf = context->buf;
3632 8 : bool first = true;
3633 : ListCell *lc;
3634 :
3635 8 : appendStringInfoString(buf, "ARRAY[");
3636 24 : foreach(lc, node->elements)
3637 : {
3638 16 : if (!first)
3639 8 : appendStringInfoString(buf, ", ");
3640 16 : deparseExpr(lfirst(lc), context);
3641 16 : first = false;
3642 : }
3643 8 : appendStringInfoChar(buf, ']');
3644 :
3645 : /* If the array is empty, we need an explicit cast to the array type. */
3646 8 : if (node->elements == NIL)
3647 0 : appendStringInfo(buf, "::%s",
3648 : deparse_type_name(node->array_typeid, -1));
3649 8 : }
3650 :
3651 : /*
3652 : * Deparse an Aggref node.
3653 : */
3654 : static void
3655 518 : deparseAggref(Aggref *node, deparse_expr_cxt *context)
3656 : {
3657 518 : StringInfo buf = context->buf;
3658 : bool use_variadic;
3659 :
3660 : /* Only basic, non-split aggregation accepted. */
3661 : Assert(node->aggsplit == AGGSPLIT_SIMPLE);
3662 :
3663 : /* Check if need to print VARIADIC (cf. ruleutils.c) */
3664 518 : use_variadic = node->aggvariadic;
3665 :
3666 : /* Find aggregate name from aggfnoid which is a pg_proc entry */
3667 518 : appendFunctionName(node->aggfnoid, context);
3668 518 : appendStringInfoChar(buf, '(');
3669 :
3670 : /* Add DISTINCT */
3671 518 : appendStringInfoString(buf, (node->aggdistinct != NIL) ? "DISTINCT " : "");
3672 :
3673 518 : if (AGGKIND_IS_ORDERED_SET(node->aggkind))
3674 : {
3675 : /* Add WITHIN GROUP (ORDER BY ..) */
3676 : ListCell *arg;
3677 16 : bool first = true;
3678 :
3679 : Assert(!node->aggvariadic);
3680 : Assert(node->aggorder != NIL);
3681 :
3682 36 : foreach(arg, node->aggdirectargs)
3683 : {
3684 20 : if (!first)
3685 4 : appendStringInfoString(buf, ", ");
3686 20 : first = false;
3687 :
3688 20 : deparseExpr((Expr *) lfirst(arg), context);
3689 : }
3690 :
3691 16 : appendStringInfoString(buf, ") WITHIN GROUP (ORDER BY ");
3692 16 : appendAggOrderBy(node->aggorder, node->args, context);
3693 : }
3694 : else
3695 : {
3696 : /* aggstar can be set only in zero-argument aggregates */
3697 502 : if (node->aggstar)
3698 136 : appendStringInfoChar(buf, '*');
3699 : else
3700 : {
3701 : ListCell *arg;
3702 366 : bool first = true;
3703 :
3704 : /* Add all the arguments */
3705 740 : foreach(arg, node->args)
3706 : {
3707 374 : TargetEntry *tle = (TargetEntry *) lfirst(arg);
3708 374 : Node *n = (Node *) tle->expr;
3709 :
3710 374 : if (tle->resjunk)
3711 8 : continue;
3712 :
3713 366 : if (!first)
3714 0 : appendStringInfoString(buf, ", ");
3715 366 : first = false;
3716 :
3717 : /* Add VARIADIC */
3718 366 : if (use_variadic && lnext(node->args, arg) == NULL)
3719 4 : appendStringInfoString(buf, "VARIADIC ");
3720 :
3721 366 : deparseExpr((Expr *) n, context);
3722 : }
3723 : }
3724 :
3725 : /* Add ORDER BY */
3726 502 : if (node->aggorder != NIL)
3727 : {
3728 44 : appendStringInfoString(buf, " ORDER BY ");
3729 44 : appendAggOrderBy(node->aggorder, node->args, context);
3730 : }
3731 : }
3732 :
3733 : /* Add FILTER (WHERE ..) */
3734 518 : if (node->aggfilter != NULL)
3735 : {
3736 24 : appendStringInfoString(buf, ") FILTER (WHERE ");
3737 24 : deparseExpr((Expr *) node->aggfilter, context);
3738 : }
3739 :
3740 518 : appendStringInfoChar(buf, ')');
3741 518 : }
3742 :
3743 : /*
3744 : * Append ORDER BY within aggregate function.
3745 : */
3746 : static void
3747 60 : appendAggOrderBy(List *orderList, List *targetList, deparse_expr_cxt *context)
3748 : {
3749 60 : StringInfo buf = context->buf;
3750 : ListCell *lc;
3751 60 : bool first = true;
3752 :
3753 124 : foreach(lc, orderList)
3754 : {
3755 64 : SortGroupClause *srt = (SortGroupClause *) lfirst(lc);
3756 : Node *sortexpr;
3757 :
3758 64 : if (!first)
3759 4 : appendStringInfoString(buf, ", ");
3760 64 : first = false;
3761 :
3762 : /* Deparse the sort expression proper. */
3763 64 : sortexpr = deparseSortGroupClause(srt->tleSortGroupRef, targetList,
3764 : false, context);
3765 : /* Add decoration as needed. */
3766 64 : appendOrderBySuffix(srt->sortop, exprType(sortexpr), srt->nulls_first,
3767 : context);
3768 : }
3769 60 : }
3770 :
3771 : /*
3772 : * Append the ASC, DESC, USING <OPERATOR> and NULLS FIRST / NULLS LAST parts
3773 : * of an ORDER BY clause.
3774 : */
3775 : static void
3776 1744 : appendOrderBySuffix(Oid sortop, Oid sortcoltype, bool nulls_first,
3777 : deparse_expr_cxt *context)
3778 : {
3779 1744 : StringInfo buf = context->buf;
3780 : TypeCacheEntry *typentry;
3781 :
3782 : /* See whether operator is default < or > for sort expr's datatype. */
3783 1744 : typentry = lookup_type_cache(sortcoltype,
3784 : TYPECACHE_LT_OPR | TYPECACHE_GT_OPR);
3785 :
3786 1744 : if (sortop == typentry->lt_opr)
3787 1698 : appendStringInfoString(buf, " ASC");
3788 46 : else if (sortop == typentry->gt_opr)
3789 30 : appendStringInfoString(buf, " DESC");
3790 : else
3791 : {
3792 : HeapTuple opertup;
3793 : Form_pg_operator operform;
3794 :
3795 16 : appendStringInfoString(buf, " USING ");
3796 :
3797 : /* Append operator name. */
3798 16 : opertup = SearchSysCache1(OPEROID, ObjectIdGetDatum(sortop));
3799 16 : if (!HeapTupleIsValid(opertup))
3800 0 : elog(ERROR, "cache lookup failed for operator %u", sortop);
3801 16 : operform = (Form_pg_operator) GETSTRUCT(opertup);
3802 16 : deparseOperatorName(buf, operform);
3803 16 : ReleaseSysCache(opertup);
3804 : }
3805 :
3806 1744 : if (nulls_first)
3807 22 : appendStringInfoString(buf, " NULLS FIRST");
3808 : else
3809 1722 : appendStringInfoString(buf, " NULLS LAST");
3810 1744 : }
3811 :
3812 : /*
3813 : * Print the representation of a parameter to be sent to the remote side.
3814 : *
3815 : * Note: we always label the Param's type explicitly rather than relying on
3816 : * transmitting a numeric type OID in PQsendQueryParams(). This allows us to
3817 : * avoid assuming that types have the same OIDs on the remote side as they
3818 : * do locally --- they need only have the same names.
3819 : */
3820 : static void
3821 58 : printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod,
3822 : deparse_expr_cxt *context)
3823 : {
3824 58 : StringInfo buf = context->buf;
3825 58 : char *ptypename = deparse_type_name(paramtype, paramtypmod);
3826 :
3827 58 : appendStringInfo(buf, "$%d::%s", paramindex, ptypename);
3828 58 : }
3829 :
3830 : /*
3831 : * Print the representation of a placeholder for a parameter that will be
3832 : * sent to the remote side at execution time.
3833 : *
3834 : * This is used when we're just trying to EXPLAIN the remote query.
3835 : * We don't have the actual value of the runtime parameter yet, and we don't
3836 : * want the remote planner to generate a plan that depends on such a value
3837 : * anyway. Thus, we can't do something simple like "$1::paramtype".
3838 : * Instead, we emit "((SELECT null::paramtype)::paramtype)".
3839 : * In all extant versions of Postgres, the planner will see that as an unknown
3840 : * constant value, which is what we want. This might need adjustment if we
3841 : * ever make the planner flatten scalar subqueries. Note: the reason for the
3842 : * apparently useless outer cast is to ensure that the representation as a
3843 : * whole will be parsed as an a_expr and not a select_with_parens; the latter
3844 : * would do the wrong thing in the context "x = ANY(...)".
3845 : */
3846 : static void
3847 408 : printRemotePlaceholder(Oid paramtype, int32 paramtypmod,
3848 : deparse_expr_cxt *context)
3849 : {
3850 408 : StringInfo buf = context->buf;
3851 408 : char *ptypename = deparse_type_name(paramtype, paramtypmod);
3852 :
3853 408 : appendStringInfo(buf, "((SELECT null::%s)::%s)", ptypename, ptypename);
3854 408 : }
3855 :
3856 : /*
3857 : * Deparse GROUP BY clause.
3858 : */
3859 : static void
3860 324 : appendGroupByClause(List *tlist, deparse_expr_cxt *context)
3861 : {
3862 324 : StringInfo buf = context->buf;
3863 324 : Query *query = context->root->parse;
3864 : ListCell *lc;
3865 324 : bool first = true;
3866 :
3867 : /* Nothing to be done, if there's no GROUP BY clause in the query. */
3868 324 : if (!query->groupClause)
3869 122 : return;
3870 :
3871 202 : appendStringInfoString(buf, " GROUP BY ");
3872 :
3873 : /*
3874 : * Queries with grouping sets are not pushed down, so we don't expect
3875 : * grouping sets here.
3876 : */
3877 : Assert(!query->groupingSets);
3878 :
3879 : /*
3880 : * We intentionally print query->groupClause not processed_groupClause,
3881 : * leaving it to the remote planner to get rid of any redundant GROUP BY
3882 : * items again. This is necessary in case processed_groupClause reduced
3883 : * to empty, and in any case the redundancy situation on the remote might
3884 : * be different than what we think here.
3885 : */
3886 428 : foreach(lc, query->groupClause)
3887 : {
3888 226 : SortGroupClause *grp = (SortGroupClause *) lfirst(lc);
3889 :
3890 226 : if (!first)
3891 24 : appendStringInfoString(buf, ", ");
3892 226 : first = false;
3893 :
3894 226 : deparseSortGroupClause(grp->tleSortGroupRef, tlist, true, context);
3895 : }
3896 : }
3897 :
3898 : /*
3899 : * Deparse ORDER BY clause defined by the given pathkeys.
3900 : *
3901 : * The clause should use Vars from context->scanrel if !has_final_sort,
3902 : * or from context->foreignrel's targetlist if has_final_sort.
3903 : *
3904 : * We find a suitable pathkey expression (some earlier step
3905 : * should have verified that there is one) and deparse it.
3906 : */
3907 : static void
3908 1426 : appendOrderByClause(List *pathkeys, bool has_final_sort,
3909 : deparse_expr_cxt *context)
3910 : {
3911 : ListCell *lcell;
3912 : int nestlevel;
3913 1426 : StringInfo buf = context->buf;
3914 1426 : bool gotone = false;
3915 :
3916 : /* Make sure any constants in the exprs are printed portably */
3917 1426 : nestlevel = set_transmission_modes();
3918 :
3919 3118 : foreach(lcell, pathkeys)
3920 : {
3921 1692 : PathKey *pathkey = lfirst(lcell);
3922 : EquivalenceMember *em;
3923 : Expr *em_expr;
3924 : Oid oprid;
3925 :
3926 1692 : if (has_final_sort)
3927 : {
3928 : /*
3929 : * By construction, context->foreignrel is the input relation to
3930 : * the final sort.
3931 : */
3932 406 : em = find_em_for_rel_target(context->root,
3933 : pathkey->pk_eclass,
3934 : context->foreignrel);
3935 : }
3936 : else
3937 1286 : em = find_em_for_rel(context->root,
3938 : pathkey->pk_eclass,
3939 : context->scanrel);
3940 :
3941 : /*
3942 : * We don't expect any error here; it would mean that shippability
3943 : * wasn't verified earlier. For the same reason, we don't recheck
3944 : * shippability of the sort operator.
3945 : */
3946 1692 : if (em == NULL)
3947 0 : elog(ERROR, "could not find pathkey item to sort");
3948 :
3949 1692 : em_expr = em->em_expr;
3950 :
3951 : /*
3952 : * If the member is a Const expression then we needn't add it to the
3953 : * ORDER BY clause. This can happen in UNION ALL queries where the
3954 : * union child targetlist has a Const. Adding these would be
3955 : * wasteful, but also, for INT columns, an integer literal would be
3956 : * seen as an ordinal column position rather than a value to sort by.
3957 : * deparseConst() does have code to handle this, but it seems less
3958 : * effort on all accounts just to skip these for ORDER BY clauses.
3959 : */
3960 1692 : if (IsA(em_expr, Const))
3961 12 : continue;
3962 :
3963 1680 : if (!gotone)
3964 : {
3965 1420 : appendStringInfoString(buf, " ORDER BY ");
3966 1420 : gotone = true;
3967 : }
3968 : else
3969 260 : appendStringInfoString(buf, ", ");
3970 :
3971 : /*
3972 : * Lookup the operator corresponding to the strategy in the opclass.
3973 : * The datatype used by the opfamily is not necessarily the same as
3974 : * the expression type (for array types for example).
3975 : */
3976 1680 : oprid = get_opfamily_member(pathkey->pk_opfamily,
3977 : em->em_datatype,
3978 : em->em_datatype,
3979 1680 : pathkey->pk_strategy);
3980 1680 : if (!OidIsValid(oprid))
3981 0 : elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
3982 : pathkey->pk_strategy, em->em_datatype, em->em_datatype,
3983 : pathkey->pk_opfamily);
3984 :
3985 1680 : deparseExpr(em_expr, context);
3986 :
3987 : /*
3988 : * Here we need to use the expression's actual type to discover
3989 : * whether the desired operator will be the default or not.
3990 : */
3991 1680 : appendOrderBySuffix(oprid, exprType((Node *) em_expr),
3992 1680 : pathkey->pk_nulls_first, context);
3993 :
3994 : }
3995 1426 : reset_transmission_modes(nestlevel);
3996 1426 : }
3997 :
3998 : /*
3999 : * Deparse LIMIT/OFFSET clause.
4000 : */
4001 : static void
4002 284 : appendLimitClause(deparse_expr_cxt *context)
4003 : {
4004 284 : PlannerInfo *root = context->root;
4005 284 : StringInfo buf = context->buf;
4006 : int nestlevel;
4007 :
4008 : /* Make sure any constants in the exprs are printed portably */
4009 284 : nestlevel = set_transmission_modes();
4010 :
4011 284 : if (root->parse->limitCount)
4012 : {
4013 284 : appendStringInfoString(buf, " LIMIT ");
4014 284 : deparseExpr((Expr *) root->parse->limitCount, context);
4015 : }
4016 284 : if (root->parse->limitOffset)
4017 : {
4018 150 : appendStringInfoString(buf, " OFFSET ");
4019 150 : deparseExpr((Expr *) root->parse->limitOffset, context);
4020 : }
4021 :
4022 284 : reset_transmission_modes(nestlevel);
4023 284 : }
4024 :
4025 : /*
4026 : * appendFunctionName
4027 : * Deparses function name from given function oid.
4028 : */
4029 : static void
4030 592 : appendFunctionName(Oid funcid, deparse_expr_cxt *context)
4031 : {
4032 592 : StringInfo buf = context->buf;
4033 : HeapTuple proctup;
4034 : Form_pg_proc procform;
4035 : const char *proname;
4036 :
4037 592 : proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
4038 592 : if (!HeapTupleIsValid(proctup))
4039 0 : elog(ERROR, "cache lookup failed for function %u", funcid);
4040 592 : procform = (Form_pg_proc) GETSTRUCT(proctup);
4041 :
4042 : /* Print schema name only if it's not pg_catalog */
4043 592 : if (procform->pronamespace != PG_CATALOG_NAMESPACE)
4044 : {
4045 : const char *schemaname;
4046 :
4047 12 : schemaname = get_namespace_name(procform->pronamespace);
4048 12 : appendStringInfo(buf, "%s.", quote_identifier(schemaname));
4049 : }
4050 :
4051 : /* Always print the function name */
4052 592 : proname = NameStr(procform->proname);
4053 592 : appendStringInfoString(buf, quote_identifier(proname));
4054 :
4055 592 : ReleaseSysCache(proctup);
4056 592 : }
4057 :
4058 : /*
4059 : * Appends a sort or group clause.
4060 : *
4061 : * Like get_rule_sortgroupclause(), returns the expression tree, so caller
4062 : * need not find it again.
4063 : */
4064 : static Node *
4065 290 : deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
4066 : deparse_expr_cxt *context)
4067 : {
4068 290 : StringInfo buf = context->buf;
4069 : TargetEntry *tle;
4070 : Expr *expr;
4071 :
4072 290 : tle = get_sortgroupref_tle(ref, tlist);
4073 290 : expr = tle->expr;
4074 :
4075 290 : if (force_colno)
4076 : {
4077 : /* Use column-number form when requested by caller. */
4078 : Assert(!tle->resjunk);
4079 226 : appendStringInfo(buf, "%d", tle->resno);
4080 : }
4081 64 : else if (expr && IsA(expr, Const))
4082 : {
4083 : /*
4084 : * Force a typecast here so that we don't emit something like "GROUP
4085 : * BY 2", which will be misconstrued as a column position rather than
4086 : * a constant.
4087 : */
4088 0 : deparseConst((Const *) expr, context, 1);
4089 : }
4090 64 : else if (!expr || IsA(expr, Var))
4091 36 : deparseExpr(expr, context);
4092 : else
4093 : {
4094 : /* Always parenthesize the expression. */
4095 28 : appendStringInfoChar(buf, '(');
4096 28 : deparseExpr(expr, context);
4097 28 : appendStringInfoChar(buf, ')');
4098 : }
4099 :
4100 290 : return (Node *) expr;
4101 : }
4102 :
4103 :
4104 : /*
4105 : * Returns true if given Var is deparsed as a subquery output column, in
4106 : * which case, *relno and *colno are set to the IDs for the relation and
4107 : * column alias to the Var provided by the subquery.
4108 : */
4109 : static bool
4110 16370 : is_subquery_var(Var *node, RelOptInfo *foreignrel, int *relno, int *colno)
4111 : {
4112 16370 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
4113 16370 : RelOptInfo *outerrel = fpinfo->outerrel;
4114 16370 : RelOptInfo *innerrel = fpinfo->innerrel;
4115 :
4116 : /* Should only be called in these cases. */
4117 : Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
4118 :
4119 : /*
4120 : * If the given relation isn't a join relation, it doesn't have any lower
4121 : * subqueries, so the Var isn't a subquery output column.
4122 : */
4123 16370 : if (!IS_JOIN_REL(foreignrel))
4124 3970 : return false;
4125 :
4126 : /*
4127 : * If the Var doesn't belong to any lower subqueries, it isn't a subquery
4128 : * output column.
4129 : */
4130 12400 : if (!bms_is_member(node->varno, fpinfo->lower_subquery_rels))
4131 12168 : return false;
4132 :
4133 232 : if (bms_is_member(node->varno, outerrel->relids))
4134 : {
4135 : /*
4136 : * If outer relation is deparsed as a subquery, the Var is an output
4137 : * column of the subquery; get the IDs for the relation/column alias.
4138 : */
4139 84 : if (fpinfo->make_outerrel_subquery)
4140 : {
4141 84 : get_relation_column_alias_ids(node, outerrel, relno, colno);
4142 84 : return true;
4143 : }
4144 :
4145 : /* Otherwise, recurse into the outer relation. */
4146 0 : return is_subquery_var(node, outerrel, relno, colno);
4147 : }
4148 : else
4149 : {
4150 : Assert(bms_is_member(node->varno, innerrel->relids));
4151 :
4152 : /*
4153 : * If inner relation is deparsed as a subquery, the Var is an output
4154 : * column of the subquery; get the IDs for the relation/column alias.
4155 : */
4156 148 : if (fpinfo->make_innerrel_subquery)
4157 : {
4158 148 : get_relation_column_alias_ids(node, innerrel, relno, colno);
4159 148 : return true;
4160 : }
4161 :
4162 : /* Otherwise, recurse into the inner relation. */
4163 0 : return is_subquery_var(node, innerrel, relno, colno);
4164 : }
4165 : }
4166 :
4167 : /*
4168 : * Get the IDs for the relation and column alias to given Var belonging to
4169 : * given relation, which are returned into *relno and *colno.
4170 : */
4171 : static void
4172 232 : get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel,
4173 : int *relno, int *colno)
4174 : {
4175 232 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
4176 : int i;
4177 : ListCell *lc;
4178 :
4179 : /* Get the relation alias ID */
4180 232 : *relno = fpinfo->relation_index;
4181 :
4182 : /* Get the column alias ID */
4183 232 : i = 1;
4184 304 : foreach(lc, foreignrel->reltarget->exprs)
4185 : {
4186 304 : Var *tlvar = (Var *) lfirst(lc);
4187 :
4188 : /*
4189 : * Match reltarget entries only on varno/varattno. Ideally there
4190 : * would be some cross-check on varnullingrels, but it's unclear what
4191 : * to do exactly; we don't have enough context to know what that value
4192 : * should be.
4193 : */
4194 304 : if (IsA(tlvar, Var) &&
4195 304 : tlvar->varno == node->varno &&
4196 288 : tlvar->varattno == node->varattno)
4197 : {
4198 232 : *colno = i;
4199 232 : return;
4200 : }
4201 72 : i++;
4202 : }
4203 :
4204 : /* Shouldn't get here */
4205 0 : elog(ERROR, "unexpected expression in subquery output");
4206 : }
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