1/*-------------------------------------------------------------------------
2 *
3 * parse_agg.c
4 * handle aggregates and window functions in parser
5 *
6 * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
8 *
9 *
10 * IDENTIFICATION
11 * src/backend/parser/parse_agg.c
12 *
13 *-------------------------------------------------------------------------
14 */
15#include "postgres.h"
16
17#include "catalog/pg_aggregate.h"
18#include "catalog/pg_constraint.h"
19#include "catalog/pg_type.h"
20#include "nodes/makefuncs.h"
21#include "nodes/nodeFuncs.h"
22#include "optimizer/optimizer.h"
23#include "parser/parse_agg.h"
24#include "parser/parse_clause.h"
25#include "parser/parse_coerce.h"
26#include "parser/parse_expr.h"
27#include "parser/parsetree.h"
28#include "rewrite/rewriteManip.h"
29#include "utils/builtins.h"
30#include "utils/lsyscache.h"
31
32
33typedef struct
34{
35 ParseState *pstate;
36 int min_varlevel;
37 int min_agglevel;
38 int sublevels_up;
39} check_agg_arguments_context;
40
41typedef struct
42{
43 ParseState *pstate;
44 Query *qry;
45 bool hasJoinRTEs;
46 List *groupClauses;
47 List *groupClauseCommonVars;
48 bool have_non_var_grouping;
49 List **func_grouped_rels;
50 int sublevels_up;
51 bool in_agg_direct_args;
52} check_ungrouped_columns_context;
53
54static int check_agg_arguments(ParseState *pstate,
55 List *directargs,
56 List *args,
57 Expr *filter);
58static bool check_agg_arguments_walker(Node *node,
59 check_agg_arguments_context *context);
60static void check_ungrouped_columns(Node *node, ParseState *pstate, Query *qry,
61 List *groupClauses, List *groupClauseVars,
62 bool have_non_var_grouping,
63 List **func_grouped_rels);
64static bool check_ungrouped_columns_walker(Node *node,
65 check_ungrouped_columns_context *context);
66static void finalize_grouping_exprs(Node *node, ParseState *pstate, Query *qry,
67 List *groupClauses, bool hasJoinRTEs,
68 bool have_non_var_grouping);
69static bool finalize_grouping_exprs_walker(Node *node,
70 check_ungrouped_columns_context *context);
71static void check_agglevels_and_constraints(ParseState *pstate, Node *expr);
72static List *expand_groupingset_node(GroupingSet *gs);
73static Node *make_agg_arg(Oid argtype, Oid argcollation);
74
75
76/*
77 * transformAggregateCall -
78 * Finish initial transformation of an aggregate call
79 *
80 * parse_func.c has recognized the function as an aggregate, and has set up
81 * all the fields of the Aggref except aggargtypes, aggdirectargs, args,
82 * aggorder, aggdistinct and agglevelsup. The passed-in args list has been
83 * through standard expression transformation and type coercion to match the
84 * agg's declared arg types, while the passed-in aggorder list hasn't been
85 * transformed at all.
86 *
87 * Here we separate the args list into direct and aggregated args, storing the
88 * former in agg->aggdirectargs and the latter in agg->args. The regular
89 * args, but not the direct args, are converted into a targetlist by inserting
90 * TargetEntry nodes. We then transform the aggorder and agg_distinct
91 * specifications to produce lists of SortGroupClause nodes for agg->aggorder
92 * and agg->aggdistinct. (For a regular aggregate, this might result in
93 * adding resjunk expressions to the targetlist; but for ordered-set
94 * aggregates the aggorder list will always be one-to-one with the aggregated
95 * args.)
96 *
97 * We must also determine which query level the aggregate actually belongs to,
98 * set agglevelsup accordingly, and mark p_hasAggs true in the corresponding
99 * pstate level.
100 */
101void
102transformAggregateCall(ParseState *pstate, Aggref *agg,
103 List *args, List *aggorder, bool agg_distinct)
104{
105 List *argtypes = NIL;
106 List *tlist = NIL;
107 List *torder = NIL;
108 List *tdistinct = NIL;
109 AttrNumber attno = 1;
110 int save_next_resno;
111 ListCell *lc;
112
113 /*
114 * Before separating the args into direct and aggregated args, make a list
115 * of their data type OIDs for use later.
116 */
117 foreach(lc, args)
118 {
119 Expr *arg = (Expr *) lfirst(lc);
120
121 argtypes = lappend_oid(argtypes, exprType((Node *) arg));
122 }
123 agg->aggargtypes = argtypes;
124
125 if (AGGKIND_IS_ORDERED_SET(agg->aggkind))
126 {
127 /*
128 * For an ordered-set agg, the args list includes direct args and
129 * aggregated args; we must split them apart.
130 */
131 int numDirectArgs = list_length(args) - list_length(aggorder);
132 List *aargs;
133 ListCell *lc2;
134
135 Assert(numDirectArgs >= 0);
136
137 aargs = list_copy_tail(args, numDirectArgs);
138 agg->aggdirectargs = list_truncate(args, numDirectArgs);
139
140 /*
141 * Build a tlist from the aggregated args, and make a sortlist entry
142 * for each one. Note that the expressions in the SortBy nodes are
143 * ignored (they are the raw versions of the transformed args); we are
144 * just looking at the sort information in the SortBy nodes.
145 */
146 forboth(lc, aargs, lc2, aggorder)
147 {
148 Expr *arg = (Expr *) lfirst(lc);
149 SortBy *sortby = (SortBy *) lfirst(lc2);
150 TargetEntry *tle;
151
152 /* We don't bother to assign column names to the entries */
153 tle = makeTargetEntry(arg, attno++, NULL, false);
154 tlist = lappend(tlist, tle);
155
156 torder = addTargetToSortList(pstate, tle,
157 torder, tlist, sortby);
158 }
159
160 /* Never any DISTINCT in an ordered-set agg */
161 Assert(!agg_distinct);
162 }
163 else
164 {
165 /* Regular aggregate, so it has no direct args */
166 agg->aggdirectargs = NIL;
167
168 /*
169 * Transform the plain list of Exprs into a targetlist.
170 */
171 foreach(lc, args)
172 {
173 Expr *arg = (Expr *) lfirst(lc);
174 TargetEntry *tle;
175
176 /* We don't bother to assign column names to the entries */
177 tle = makeTargetEntry(arg, attno++, NULL, false);
178 tlist = lappend(tlist, tle);
179 }
180
181 /*
182 * If we have an ORDER BY, transform it. This will add columns to the
183 * tlist if they appear in ORDER BY but weren't already in the arg
184 * list. They will be marked resjunk = true so we can tell them apart
185 * from regular aggregate arguments later.
186 *
187 * We need to mess with p_next_resno since it will be used to number
188 * any new targetlist entries.
189 */
190 save_next_resno = pstate->p_next_resno;
191 pstate->p_next_resno = attno;
192
193 torder = transformSortClause(pstate,
194 aggorder,
195 &tlist,
196 EXPR_KIND_ORDER_BY,
197 true /* force SQL99 rules */ );
198
199 /*
200 * If we have DISTINCT, transform that to produce a distinctList.
201 */
202 if (agg_distinct)
203 {
204 tdistinct = transformDistinctClause(pstate, &tlist, torder, true);
205
206 /*
207 * Remove this check if executor support for hashed distinct for
208 * aggregates is ever added.
209 */
210 foreach(lc, tdistinct)
211 {
212 SortGroupClause *sortcl = (SortGroupClause *) lfirst(lc);
213
214 if (!OidIsValid(sortcl->sortop))
215 {
216 Node *expr = get_sortgroupclause_expr(sortcl, tlist);
217
218 ereport(ERROR,
219 (errcode(ERRCODE_UNDEFINED_FUNCTION),
220 errmsg("could not identify an ordering operator for type %s",
221 format_type_be(exprType(expr))),
222 errdetail("Aggregates with DISTINCT must be able to sort their inputs."),
223 parser_errposition(pstate, exprLocation(expr))));
224 }
225 }
226 }
227
228 pstate->p_next_resno = save_next_resno;
229 }
230
231 /* Update the Aggref with the transformation results */
232 agg->args = tlist;
233 agg->aggorder = torder;
234 agg->aggdistinct = tdistinct;
235
236 check_agglevels_and_constraints(pstate, (Node *) agg);
237}
238
239/*
240 * transformGroupingFunc
241 * Transform a GROUPING expression
242 *
243 * GROUPING() behaves very like an aggregate. Processing of levels and nesting
244 * is done as for aggregates. We set p_hasAggs for these expressions too.
245 */
246Node *
247transformGroupingFunc(ParseState *pstate, GroupingFunc *p)
248{
249 ListCell *lc;
250 List *args = p->args;
251 List *result_list = NIL;
252 GroupingFunc *result = makeNode(GroupingFunc);
253
254 if (list_length(args) > 31)
255 ereport(ERROR,
256 (errcode(ERRCODE_TOO_MANY_ARGUMENTS),
257 errmsg("GROUPING must have fewer than 32 arguments"),
258 parser_errposition(pstate, p->location)));
259
260 foreach(lc, args)
261 {
262 Node *current_result;
263
264 current_result = transformExpr(pstate, (Node *) lfirst(lc), pstate->p_expr_kind);
265
266 /* acceptability of expressions is checked later */
267
268 result_list = lappend(result_list, current_result);
269 }
270
271 result->args = result_list;
272 result->location = p->location;
273
274 check_agglevels_and_constraints(pstate, (Node *) result);
275
276 return (Node *) result;
277}
278
279/*
280 * Aggregate functions and grouping operations (which are combined in the spec
281 * as <set function specification>) are very similar with regard to level and
282 * nesting restrictions (though we allow a lot more things than the spec does).
283 * Centralise those restrictions here.
284 */
285static void
286check_agglevels_and_constraints(ParseState *pstate, Node *expr)
287{
288 List *directargs = NIL;
289 List *args = NIL;
290 Expr *filter = NULL;
291 int min_varlevel;
292 int location = -1;
293 Index *p_levelsup;
294 const char *err;
295 bool errkind;
296 bool isAgg = IsA(expr, Aggref);
297
298 if (isAgg)
299 {
300 Aggref *agg = (Aggref *) expr;
301
302 directargs = agg->aggdirectargs;
303 args = agg->args;
304 filter = agg->aggfilter;
305 location = agg->location;
306 p_levelsup = &agg->agglevelsup;
307 }
308 else
309 {
310 GroupingFunc *grp = (GroupingFunc *) expr;
311
312 args = grp->args;
313 location = grp->location;
314 p_levelsup = &grp->agglevelsup;
315 }
316
317 /*
318 * Check the arguments to compute the aggregate's level and detect
319 * improper nesting.
320 */
321 min_varlevel = check_agg_arguments(pstate,
322 directargs,
323 args,
324 filter);
325
326 *p_levelsup = min_varlevel;
327
328 /* Mark the correct pstate level as having aggregates */
329 while (min_varlevel-- > 0)
330 pstate = pstate->parentParseState;
331 pstate->p_hasAggs = true;
332
333 /*
334 * Check to see if the aggregate function is in an invalid place within
335 * its aggregation query.
336 *
337 * For brevity we support two schemes for reporting an error here: set
338 * "err" to a custom message, or set "errkind" true if the error context
339 * is sufficiently identified by what ParseExprKindName will return, *and*
340 * what it will return is just a SQL keyword. (Otherwise, use a custom
341 * message to avoid creating translation problems.)
342 */
343 err = NULL;
344 errkind = false;
345 switch (pstate->p_expr_kind)
346 {
347 case EXPR_KIND_NONE:
348 Assert(false); /* can't happen */
349 break;
350 case EXPR_KIND_OTHER:
351
352 /*
353 * Accept aggregate/grouping here; caller must throw error if
354 * wanted
355 */
356 break;
357 case EXPR_KIND_JOIN_ON:
358 case EXPR_KIND_JOIN_USING:
359 if (isAgg)
360 err = _("aggregate functions are not allowed in JOIN conditions");
361 else
362 err = _("grouping operations are not allowed in JOIN conditions");
363
364 break;
365 case EXPR_KIND_FROM_SUBSELECT:
366 /* Should only be possible in a LATERAL subquery */
367 Assert(pstate->p_lateral_active);
368
369 /*
370 * Aggregate/grouping scope rules make it worth being explicit
371 * here
372 */
373 if (isAgg)
374 err = _("aggregate functions are not allowed in FROM clause of their own query level");
375 else
376 err = _("grouping operations are not allowed in FROM clause of their own query level");
377
378 break;
379 case EXPR_KIND_FROM_FUNCTION:
380 if (isAgg)
381 err = _("aggregate functions are not allowed in functions in FROM");
382 else
383 err = _("grouping operations are not allowed in functions in FROM");
384
385 break;
386 case EXPR_KIND_WHERE:
387 errkind = true;
388 break;
389 case EXPR_KIND_POLICY:
390 if (isAgg)
391 err = _("aggregate functions are not allowed in policy expressions");
392 else
393 err = _("grouping operations are not allowed in policy expressions");
394
395 break;
396 case EXPR_KIND_HAVING:
397 /* okay */
398 break;
399 case EXPR_KIND_FILTER:
400 errkind = true;
401 break;
402 case EXPR_KIND_WINDOW_PARTITION:
403 /* okay */
404 break;
405 case EXPR_KIND_WINDOW_ORDER:
406 /* okay */
407 break;
408 case EXPR_KIND_WINDOW_FRAME_RANGE:
409 if (isAgg)
410 err = _("aggregate functions are not allowed in window RANGE");
411 else
412 err = _("grouping operations are not allowed in window RANGE");
413
414 break;
415 case EXPR_KIND_WINDOW_FRAME_ROWS:
416 if (isAgg)
417 err = _("aggregate functions are not allowed in window ROWS");
418 else
419 err = _("grouping operations are not allowed in window ROWS");
420
421 break;
422 case EXPR_KIND_WINDOW_FRAME_GROUPS:
423 if (isAgg)
424 err = _("aggregate functions are not allowed in window GROUPS");
425 else
426 err = _("grouping operations are not allowed in window GROUPS");
427
428 break;
429 case EXPR_KIND_SELECT_TARGET:
430 /* okay */
431 break;
432 case EXPR_KIND_INSERT_TARGET:
433 case EXPR_KIND_UPDATE_SOURCE:
434 case EXPR_KIND_UPDATE_TARGET:
435 errkind = true;
436 break;
437 case EXPR_KIND_GROUP_BY:
438 errkind = true;
439 break;
440 case EXPR_KIND_ORDER_BY:
441 /* okay */
442 break;
443 case EXPR_KIND_DISTINCT_ON:
444 /* okay */
445 break;
446 case EXPR_KIND_LIMIT:
447 case EXPR_KIND_OFFSET:
448 errkind = true;
449 break;
450 case EXPR_KIND_RETURNING:
451 errkind = true;
452 break;
453 case EXPR_KIND_VALUES:
454 case EXPR_KIND_VALUES_SINGLE:
455 errkind = true;
456 break;
457 case EXPR_KIND_CHECK_CONSTRAINT:
458 case EXPR_KIND_DOMAIN_CHECK:
459 if (isAgg)
460 err = _("aggregate functions are not allowed in check constraints");
461 else
462 err = _("grouping operations are not allowed in check constraints");
463
464 break;
465 case EXPR_KIND_COLUMN_DEFAULT:
466 case EXPR_KIND_FUNCTION_DEFAULT:
467
468 if (isAgg)
469 err = _("aggregate functions are not allowed in DEFAULT expressions");
470 else
471 err = _("grouping operations are not allowed in DEFAULT expressions");
472
473 break;
474 case EXPR_KIND_INDEX_EXPRESSION:
475 if (isAgg)
476 err = _("aggregate functions are not allowed in index expressions");
477 else
478 err = _("grouping operations are not allowed in index expressions");
479
480 break;
481 case EXPR_KIND_INDEX_PREDICATE:
482 if (isAgg)
483 err = _("aggregate functions are not allowed in index predicates");
484 else
485 err = _("grouping operations are not allowed in index predicates");
486
487 break;
488 case EXPR_KIND_ALTER_COL_TRANSFORM:
489 if (isAgg)
490 err = _("aggregate functions are not allowed in transform expressions");
491 else
492 err = _("grouping operations are not allowed in transform expressions");
493
494 break;
495 case EXPR_KIND_EXECUTE_PARAMETER:
496 if (isAgg)
497 err = _("aggregate functions are not allowed in EXECUTE parameters");
498 else
499 err = _("grouping operations are not allowed in EXECUTE parameters");
500
501 break;
502 case EXPR_KIND_TRIGGER_WHEN:
503 if (isAgg)
504 err = _("aggregate functions are not allowed in trigger WHEN conditions");
505 else
506 err = _("grouping operations are not allowed in trigger WHEN conditions");
507
508 break;
509 case EXPR_KIND_PARTITION_BOUND:
510 if (isAgg)
511 err = _("aggregate functions are not allowed in partition bound");
512 else
513 err = _("grouping operations are not allowed in partition bound");
514
515 break;
516 case EXPR_KIND_PARTITION_EXPRESSION:
517 if (isAgg)
518 err = _("aggregate functions are not allowed in partition key expressions");
519 else
520 err = _("grouping operations are not allowed in partition key expressions");
521
522 break;
523 case EXPR_KIND_GENERATED_COLUMN:
524
525 if (isAgg)
526 err = _("aggregate functions are not allowed in column generation expressions");
527 else
528 err = _("grouping operations are not allowed in column generation expressions");
529
530 break;
531
532 case EXPR_KIND_CALL_ARGUMENT:
533 if (isAgg)
534 err = _("aggregate functions are not allowed in CALL arguments");
535 else
536 err = _("grouping operations are not allowed in CALL arguments");
537
538 break;
539
540 case EXPR_KIND_COPY_WHERE:
541 if (isAgg)
542 err = _("aggregate functions are not allowed in COPY FROM WHERE conditions");
543 else
544 err = _("grouping operations are not allowed in COPY FROM WHERE conditions");
545
546 break;
547
548 /*
549 * There is intentionally no default: case here, so that the
550 * compiler will warn if we add a new ParseExprKind without
551 * extending this switch. If we do see an unrecognized value at
552 * runtime, the behavior will be the same as for EXPR_KIND_OTHER,
553 * which is sane anyway.
554 */
555 }
556
557 if (err)
558 ereport(ERROR,
559 (errcode(ERRCODE_GROUPING_ERROR),
560 errmsg_internal("%s", err),
561 parser_errposition(pstate, location)));
562
563 if (errkind)
564 {
565 if (isAgg)
566 /* translator: %s is name of a SQL construct, eg GROUP BY */
567 err = _("aggregate functions are not allowed in %s");
568 else
569 /* translator: %s is name of a SQL construct, eg GROUP BY */
570 err = _("grouping operations are not allowed in %s");
571
572 ereport(ERROR,
573 (errcode(ERRCODE_GROUPING_ERROR),
574 errmsg_internal(err,
575 ParseExprKindName(pstate->p_expr_kind)),
576 parser_errposition(pstate, location)));
577 }
578}
579
580/*
581 * check_agg_arguments
582 * Scan the arguments of an aggregate function to determine the
583 * aggregate's semantic level (zero is the current select's level,
584 * one is its parent, etc).
585 *
586 * The aggregate's level is the same as the level of the lowest-level variable
587 * or aggregate in its aggregated arguments (including any ORDER BY columns)
588 * or filter expression; or if it contains no variables at all, we presume it
589 * to be local.
590 *
591 * Vars/Aggs in direct arguments are *not* counted towards determining the
592 * agg's level, as those arguments aren't evaluated per-row but only
593 * per-group, and so in some sense aren't really agg arguments. However,
594 * this can mean that we decide an agg is upper-level even when its direct
595 * args contain lower-level Vars/Aggs, and that case has to be disallowed.
596 * (This is a little strange, but the SQL standard seems pretty definite that
597 * direct args are not to be considered when setting the agg's level.)
598 *
599 * We also take this opportunity to detect any aggregates or window functions
600 * nested within the arguments. We can throw error immediately if we find
601 * a window function. Aggregates are a bit trickier because it's only an
602 * error if the inner aggregate is of the same semantic level as the outer,
603 * which we can't know until we finish scanning the arguments.
604 */
605static int
606check_agg_arguments(ParseState *pstate,
607 List *directargs,
608 List *args,
609 Expr *filter)
610{
611 int agglevel;
612 check_agg_arguments_context context;
613
614 context.pstate = pstate;
615 context.min_varlevel = -1; /* signifies nothing found yet */
616 context.min_agglevel = -1;
617 context.sublevels_up = 0;
618
619 (void) expression_tree_walker((Node *) args,
620 check_agg_arguments_walker,
621 (void *) &context);
622
623 (void) expression_tree_walker((Node *) filter,
624 check_agg_arguments_walker,
625 (void *) &context);
626
627 /*
628 * If we found no vars nor aggs at all, it's a level-zero aggregate;
629 * otherwise, its level is the minimum of vars or aggs.
630 */
631 if (context.min_varlevel < 0)
632 {
633 if (context.min_agglevel < 0)
634 agglevel = 0;
635 else
636 agglevel = context.min_agglevel;
637 }
638 else if (context.min_agglevel < 0)
639 agglevel = context.min_varlevel;
640 else
641 agglevel = Min(context.min_varlevel, context.min_agglevel);
642
643 /*
644 * If there's a nested aggregate of the same semantic level, complain.
645 */
646 if (agglevel == context.min_agglevel)
647 {
648 int aggloc;
649
650 aggloc = locate_agg_of_level((Node *) args, agglevel);
651 if (aggloc < 0)
652 aggloc = locate_agg_of_level((Node *) filter, agglevel);
653 ereport(ERROR,
654 (errcode(ERRCODE_GROUPING_ERROR),
655 errmsg("aggregate function calls cannot be nested"),
656 parser_errposition(pstate, aggloc)));
657 }
658
659 /*
660 * Now check for vars/aggs in the direct arguments, and throw error if
661 * needed. Note that we allow a Var of the agg's semantic level, but not
662 * an Agg of that level. In principle such Aggs could probably be
663 * supported, but it would create an ordering dependency among the
664 * aggregates at execution time. Since the case appears neither to be
665 * required by spec nor particularly useful, we just treat it as a
666 * nested-aggregate situation.
667 */
668 if (directargs)
669 {
670 context.min_varlevel = -1;
671 context.min_agglevel = -1;
672 (void) expression_tree_walker((Node *) directargs,
673 check_agg_arguments_walker,
674 (void *) &context);
675 if (context.min_varlevel >= 0 && context.min_varlevel < agglevel)
676 ereport(ERROR,
677 (errcode(ERRCODE_GROUPING_ERROR),
678 errmsg("outer-level aggregate cannot contain a lower-level variable in its direct arguments"),
679 parser_errposition(pstate,
680 locate_var_of_level((Node *) directargs,
681 context.min_varlevel))));
682 if (context.min_agglevel >= 0 && context.min_agglevel <= agglevel)
683 ereport(ERROR,
684 (errcode(ERRCODE_GROUPING_ERROR),
685 errmsg("aggregate function calls cannot be nested"),
686 parser_errposition(pstate,
687 locate_agg_of_level((Node *) directargs,
688 context.min_agglevel))));
689 }
690 return agglevel;
691}
692
693static bool
694check_agg_arguments_walker(Node *node,
695 check_agg_arguments_context *context)
696{
697 if (node == NULL)
698 return false;
699 if (IsA(node, Var))
700 {
701 int varlevelsup = ((Var *) node)->varlevelsup;
702
703 /* convert levelsup to frame of reference of original query */
704 varlevelsup -= context->sublevels_up;
705 /* ignore local vars of subqueries */
706 if (varlevelsup >= 0)
707 {
708 if (context->min_varlevel < 0 ||
709 context->min_varlevel > varlevelsup)
710 context->min_varlevel = varlevelsup;
711 }
712 return false;
713 }
714 if (IsA(node, Aggref))
715 {
716 int agglevelsup = ((Aggref *) node)->agglevelsup;
717
718 /* convert levelsup to frame of reference of original query */
719 agglevelsup -= context->sublevels_up;
720 /* ignore local aggs of subqueries */
721 if (agglevelsup >= 0)
722 {
723 if (context->min_agglevel < 0 ||
724 context->min_agglevel > agglevelsup)
725 context->min_agglevel = agglevelsup;
726 }
727 /* no need to examine args of the inner aggregate */
728 return false;
729 }
730 if (IsA(node, GroupingFunc))
731 {
732 int agglevelsup = ((GroupingFunc *) node)->agglevelsup;
733
734 /* convert levelsup to frame of reference of original query */
735 agglevelsup -= context->sublevels_up;
736 /* ignore local aggs of subqueries */
737 if (agglevelsup >= 0)
738 {
739 if (context->min_agglevel < 0 ||
740 context->min_agglevel > agglevelsup)
741 context->min_agglevel = agglevelsup;
742 }
743 /* Continue and descend into subtree */
744 }
745
746 /*
747 * SRFs and window functions can be rejected immediately, unless we are
748 * within a sub-select within the aggregate's arguments; in that case
749 * they're OK.
750 */
751 if (context->sublevels_up == 0)
752 {
753 if ((IsA(node, FuncExpr) &&((FuncExpr *) node)->funcretset) ||
754 (IsA(node, OpExpr) &&((OpExpr *) node)->opretset))
755 ereport(ERROR,
756 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
757 errmsg("aggregate function calls cannot contain set-returning function calls"),
758 errhint("You might be able to move the set-returning function into a LATERAL FROM item."),
759 parser_errposition(context->pstate, exprLocation(node))));
760 if (IsA(node, WindowFunc))
761 ereport(ERROR,
762 (errcode(ERRCODE_GROUPING_ERROR),
763 errmsg("aggregate function calls cannot contain window function calls"),
764 parser_errposition(context->pstate,
765 ((WindowFunc *) node)->location)));
766 }
767 if (IsA(node, Query))
768 {
769 /* Recurse into subselects */
770 bool result;
771
772 context->sublevels_up++;
773 result = query_tree_walker((Query *) node,
774 check_agg_arguments_walker,
775 (void *) context,
776 0);
777 context->sublevels_up--;
778 return result;
779 }
780
781 return expression_tree_walker(node,
782 check_agg_arguments_walker,
783 (void *) context);
784}
785
786/*
787 * transformWindowFuncCall -
788 * Finish initial transformation of a window function call
789 *
790 * parse_func.c has recognized the function as a window function, and has set
791 * up all the fields of the WindowFunc except winref. Here we must (1) add
792 * the WindowDef to the pstate (if not a duplicate of one already present) and
793 * set winref to link to it; and (2) mark p_hasWindowFuncs true in the pstate.
794 * Unlike aggregates, only the most closely nested pstate level need be
795 * considered --- there are no "outer window functions" per SQL spec.
796 */
797void
798transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc,
799 WindowDef *windef)
800{
801 const char *err;
802 bool errkind;
803
804 /*
805 * A window function call can't contain another one (but aggs are OK). XXX
806 * is this required by spec, or just an unimplemented feature?
807 *
808 * Note: we don't need to check the filter expression here, because the
809 * context checks done below and in transformAggregateCall would have
810 * already rejected any window funcs or aggs within the filter.
811 */
812 if (pstate->p_hasWindowFuncs &&
813 contain_windowfuncs((Node *) wfunc->args))
814 ereport(ERROR,
815 (errcode(ERRCODE_WINDOWING_ERROR),
816 errmsg("window function calls cannot be nested"),
817 parser_errposition(pstate,
818 locate_windowfunc((Node *) wfunc->args))));
819
820 /*
821 * Check to see if the window function is in an invalid place within the
822 * query.
823 *
824 * For brevity we support two schemes for reporting an error here: set
825 * "err" to a custom message, or set "errkind" true if the error context
826 * is sufficiently identified by what ParseExprKindName will return, *and*
827 * what it will return is just a SQL keyword. (Otherwise, use a custom
828 * message to avoid creating translation problems.)
829 */
830 err = NULL;
831 errkind = false;
832 switch (pstate->p_expr_kind)
833 {
834 case EXPR_KIND_NONE:
835 Assert(false); /* can't happen */
836 break;
837 case EXPR_KIND_OTHER:
838 /* Accept window func here; caller must throw error if wanted */
839 break;
840 case EXPR_KIND_JOIN_ON:
841 case EXPR_KIND_JOIN_USING:
842 err = _("window functions are not allowed in JOIN conditions");
843 break;
844 case EXPR_KIND_FROM_SUBSELECT:
845 /* can't get here, but just in case, throw an error */
846 errkind = true;
847 break;
848 case EXPR_KIND_FROM_FUNCTION:
849 err = _("window functions are not allowed in functions in FROM");
850 break;
851 case EXPR_KIND_WHERE:
852 errkind = true;
853 break;
854 case EXPR_KIND_POLICY:
855 err = _("window functions are not allowed in policy expressions");
856 break;
857 case EXPR_KIND_HAVING:
858 errkind = true;
859 break;
860 case EXPR_KIND_FILTER:
861 errkind = true;
862 break;
863 case EXPR_KIND_WINDOW_PARTITION:
864 case EXPR_KIND_WINDOW_ORDER:
865 case EXPR_KIND_WINDOW_FRAME_RANGE:
866 case EXPR_KIND_WINDOW_FRAME_ROWS:
867 case EXPR_KIND_WINDOW_FRAME_GROUPS:
868 err = _("window functions are not allowed in window definitions");
869 break;
870 case EXPR_KIND_SELECT_TARGET:
871 /* okay */
872 break;
873 case EXPR_KIND_INSERT_TARGET:
874 case EXPR_KIND_UPDATE_SOURCE:
875 case EXPR_KIND_UPDATE_TARGET:
876 errkind = true;
877 break;
878 case EXPR_KIND_GROUP_BY:
879 errkind = true;
880 break;
881 case EXPR_KIND_ORDER_BY:
882 /* okay */
883 break;
884 case EXPR_KIND_DISTINCT_ON:
885 /* okay */
886 break;
887 case EXPR_KIND_LIMIT:
888 case EXPR_KIND_OFFSET:
889 errkind = true;
890 break;
891 case EXPR_KIND_RETURNING:
892 errkind = true;
893 break;
894 case EXPR_KIND_VALUES:
895 case EXPR_KIND_VALUES_SINGLE:
896 errkind = true;
897 break;
898 case EXPR_KIND_CHECK_CONSTRAINT:
899 case EXPR_KIND_DOMAIN_CHECK:
900 err = _("window functions are not allowed in check constraints");
901 break;
902 case EXPR_KIND_COLUMN_DEFAULT:
903 case EXPR_KIND_FUNCTION_DEFAULT:
904 err = _("window functions are not allowed in DEFAULT expressions");
905 break;
906 case EXPR_KIND_INDEX_EXPRESSION:
907 err = _("window functions are not allowed in index expressions");
908 break;
909 case EXPR_KIND_INDEX_PREDICATE:
910 err = _("window functions are not allowed in index predicates");
911 break;
912 case EXPR_KIND_ALTER_COL_TRANSFORM:
913 err = _("window functions are not allowed in transform expressions");
914 break;
915 case EXPR_KIND_EXECUTE_PARAMETER:
916 err = _("window functions are not allowed in EXECUTE parameters");
917 break;
918 case EXPR_KIND_TRIGGER_WHEN:
919 err = _("window functions are not allowed in trigger WHEN conditions");
920 break;
921 case EXPR_KIND_PARTITION_BOUND:
922 err = _("window functions are not allowed in partition bound");
923 break;
924 case EXPR_KIND_PARTITION_EXPRESSION:
925 err = _("window functions are not allowed in partition key expressions");
926 break;
927 case EXPR_KIND_CALL_ARGUMENT:
928 err = _("window functions are not allowed in CALL arguments");
929 break;
930 case EXPR_KIND_COPY_WHERE:
931 err = _("window functions are not allowed in COPY FROM WHERE conditions");
932 break;
933 case EXPR_KIND_GENERATED_COLUMN:
934 err = _("window functions are not allowed in column generation expressions");
935 break;
936
937 /*
938 * There is intentionally no default: case here, so that the
939 * compiler will warn if we add a new ParseExprKind without
940 * extending this switch. If we do see an unrecognized value at
941 * runtime, the behavior will be the same as for EXPR_KIND_OTHER,
942 * which is sane anyway.
943 */
944 }
945 if (err)
946 ereport(ERROR,
947 (errcode(ERRCODE_WINDOWING_ERROR),
948 errmsg_internal("%s", err),
949 parser_errposition(pstate, wfunc->location)));
950 if (errkind)
951 ereport(ERROR,
952 (errcode(ERRCODE_WINDOWING_ERROR),
953 /* translator: %s is name of a SQL construct, eg GROUP BY */
954 errmsg("window functions are not allowed in %s",
955 ParseExprKindName(pstate->p_expr_kind)),
956 parser_errposition(pstate, wfunc->location)));
957
958 /*
959 * If the OVER clause just specifies a window name, find that WINDOW
960 * clause (which had better be present). Otherwise, try to match all the
961 * properties of the OVER clause, and make a new entry in the p_windowdefs
962 * list if no luck.
963 */
964 if (windef->name)
965 {
966 Index winref = 0;
967 ListCell *lc;
968
969 Assert(windef->refname == NULL &&
970 windef->partitionClause == NIL &&
971 windef->orderClause == NIL &&
972 windef->frameOptions == FRAMEOPTION_DEFAULTS);
973
974 foreach(lc, pstate->p_windowdefs)
975 {
976 WindowDef *refwin = (WindowDef *) lfirst(lc);
977
978 winref++;
979 if (refwin->name && strcmp(refwin->name, windef->name) == 0)
980 {
981 wfunc->winref = winref;
982 break;
983 }
984 }
985 if (lc == NULL) /* didn't find it? */
986 ereport(ERROR,
987 (errcode(ERRCODE_UNDEFINED_OBJECT),
988 errmsg("window \"%s\" does not exist", windef->name),
989 parser_errposition(pstate, windef->location)));
990 }
991 else
992 {
993 Index winref = 0;
994 ListCell *lc;
995
996 foreach(lc, pstate->p_windowdefs)
997 {
998 WindowDef *refwin = (WindowDef *) lfirst(lc);
999
1000 winref++;
1001 if (refwin->refname && windef->refname &&
1002 strcmp(refwin->refname, windef->refname) == 0)
1003 /* matched on refname */ ;
1004 else if (!refwin->refname && !windef->refname)
1005 /* matched, no refname */ ;
1006 else
1007 continue;
1008 if (equal(refwin->partitionClause, windef->partitionClause) &&
1009 equal(refwin->orderClause, windef->orderClause) &&
1010 refwin->frameOptions == windef->frameOptions &&
1011 equal(refwin->startOffset, windef->startOffset) &&
1012 equal(refwin->endOffset, windef->endOffset))
1013 {
1014 /* found a duplicate window specification */
1015 wfunc->winref = winref;
1016 break;
1017 }
1018 }
1019 if (lc == NULL) /* didn't find it? */
1020 {
1021 pstate->p_windowdefs = lappend(pstate->p_windowdefs, windef);
1022 wfunc->winref = list_length(pstate->p_windowdefs);
1023 }
1024 }
1025
1026 pstate->p_hasWindowFuncs = true;
1027}
1028
1029/*
1030 * parseCheckAggregates
1031 * Check for aggregates where they shouldn't be and improper grouping.
1032 * This function should be called after the target list and qualifications
1033 * are finalized.
1034 *
1035 * Misplaced aggregates are now mostly detected in transformAggregateCall,
1036 * but it seems more robust to check for aggregates in recursive queries
1037 * only after everything is finalized. In any case it's hard to detect
1038 * improper grouping on-the-fly, so we have to make another pass over the
1039 * query for that.
1040 */
1041void
1042parseCheckAggregates(ParseState *pstate, Query *qry)
1043{
1044 List *gset_common = NIL;
1045 List *groupClauses = NIL;
1046 List *groupClauseCommonVars = NIL;
1047 bool have_non_var_grouping;
1048 List *func_grouped_rels = NIL;
1049 ListCell *l;
1050 bool hasJoinRTEs;
1051 bool hasSelfRefRTEs;
1052 Node *clause;
1053
1054 /* This should only be called if we found aggregates or grouping */
1055 Assert(pstate->p_hasAggs || qry->groupClause || qry->havingQual || qry->groupingSets);
1056
1057 /*
1058 * If we have grouping sets, expand them and find the intersection of all
1059 * sets.
1060 */
1061 if (qry->groupingSets)
1062 {
1063 /*
1064 * The limit of 4096 is arbitrary and exists simply to avoid resource
1065 * issues from pathological constructs.
1066 */
1067 List *gsets = expand_grouping_sets(qry->groupingSets, 4096);
1068
1069 if (!gsets)
1070 ereport(ERROR,
1071 (errcode(ERRCODE_STATEMENT_TOO_COMPLEX),
1072 errmsg("too many grouping sets present (maximum 4096)"),
1073 parser_errposition(pstate,
1074 qry->groupClause
1075 ? exprLocation((Node *) qry->groupClause)
1076 : exprLocation((Node *) qry->groupingSets))));
1077
1078 /*
1079 * The intersection will often be empty, so help things along by
1080 * seeding the intersect with the smallest set.
1081 */
1082 gset_common = linitial(gsets);
1083
1084 if (gset_common)
1085 {
1086 for_each_cell(l, lnext(list_head(gsets)))
1087 {
1088 gset_common = list_intersection_int(gset_common, lfirst(l));
1089 if (!gset_common)
1090 break;
1091 }
1092 }
1093
1094 /*
1095 * If there was only one grouping set in the expansion, AND if the
1096 * groupClause is non-empty (meaning that the grouping set is not
1097 * empty either), then we can ditch the grouping set and pretend we
1098 * just had a normal GROUP BY.
1099 */
1100 if (list_length(gsets) == 1 && qry->groupClause)
1101 qry->groupingSets = NIL;
1102 }
1103
1104 /*
1105 * Scan the range table to see if there are JOIN or self-reference CTE
1106 * entries. We'll need this info below.
1107 */
1108 hasJoinRTEs = hasSelfRefRTEs = false;
1109 foreach(l, pstate->p_rtable)
1110 {
1111 RangeTblEntry *rte = (RangeTblEntry *) lfirst(l);
1112
1113 if (rte->rtekind == RTE_JOIN)
1114 hasJoinRTEs = true;
1115 else if (rte->rtekind == RTE_CTE && rte->self_reference)
1116 hasSelfRefRTEs = true;
1117 }
1118
1119 /*
1120 * Build a list of the acceptable GROUP BY expressions for use by
1121 * check_ungrouped_columns().
1122 *
1123 * We get the TLE, not just the expr, because GROUPING wants to know the
1124 * sortgroupref.
1125 */
1126 foreach(l, qry->groupClause)
1127 {
1128 SortGroupClause *grpcl = (SortGroupClause *) lfirst(l);
1129 TargetEntry *expr;
1130
1131 expr = get_sortgroupclause_tle(grpcl, qry->targetList);
1132 if (expr == NULL)
1133 continue; /* probably cannot happen */
1134
1135 groupClauses = lcons(expr, groupClauses);
1136 }
1137
1138 /*
1139 * If there are join alias vars involved, we have to flatten them to the
1140 * underlying vars, so that aliased and unaliased vars will be correctly
1141 * taken as equal. We can skip the expense of doing this if no rangetable
1142 * entries are RTE_JOIN kind.
1143 */
1144 if (hasJoinRTEs)
1145 groupClauses = (List *) flatten_join_alias_vars(qry,
1146 (Node *) groupClauses);
1147
1148 /*
1149 * Detect whether any of the grouping expressions aren't simple Vars; if
1150 * they're all Vars then we don't have to work so hard in the recursive
1151 * scans. (Note we have to flatten aliases before this.)
1152 *
1153 * Track Vars that are included in all grouping sets separately in
1154 * groupClauseCommonVars, since these are the only ones we can use to
1155 * check for functional dependencies.
1156 */
1157 have_non_var_grouping = false;
1158 foreach(l, groupClauses)
1159 {
1160 TargetEntry *tle = lfirst(l);
1161
1162 if (!IsA(tle->expr, Var))
1163 {
1164 have_non_var_grouping = true;
1165 }
1166 else if (!qry->groupingSets ||
1167 list_member_int(gset_common, tle->ressortgroupref))
1168 {
1169 groupClauseCommonVars = lappend(groupClauseCommonVars, tle->expr);
1170 }
1171 }
1172
1173 /*
1174 * Check the targetlist and HAVING clause for ungrouped variables.
1175 *
1176 * Note: because we check resjunk tlist elements as well as regular ones,
1177 * this will also find ungrouped variables that came from ORDER BY and
1178 * WINDOW clauses. For that matter, it's also going to examine the
1179 * grouping expressions themselves --- but they'll all pass the test ...
1180 *
1181 * We also finalize GROUPING expressions, but for that we need to traverse
1182 * the original (unflattened) clause in order to modify nodes.
1183 */
1184 clause = (Node *) qry->targetList;
1185 finalize_grouping_exprs(clause, pstate, qry,
1186 groupClauses, hasJoinRTEs,
1187 have_non_var_grouping);
1188 if (hasJoinRTEs)
1189 clause = flatten_join_alias_vars(qry, clause);
1190 check_ungrouped_columns(clause, pstate, qry,
1191 groupClauses, groupClauseCommonVars,
1192 have_non_var_grouping,
1193 &func_grouped_rels);
1194
1195 clause = (Node *) qry->havingQual;
1196 finalize_grouping_exprs(clause, pstate, qry,
1197 groupClauses, hasJoinRTEs,
1198 have_non_var_grouping);
1199 if (hasJoinRTEs)
1200 clause = flatten_join_alias_vars(qry, clause);
1201 check_ungrouped_columns(clause, pstate, qry,
1202 groupClauses, groupClauseCommonVars,
1203 have_non_var_grouping,
1204 &func_grouped_rels);
1205
1206 /*
1207 * Per spec, aggregates can't appear in a recursive term.
1208 */
1209 if (pstate->p_hasAggs && hasSelfRefRTEs)
1210 ereport(ERROR,
1211 (errcode(ERRCODE_INVALID_RECURSION),
1212 errmsg("aggregate functions are not allowed in a recursive query's recursive term"),
1213 parser_errposition(pstate,
1214 locate_agg_of_level((Node *) qry, 0))));
1215}
1216
1217/*
1218 * check_ungrouped_columns -
1219 * Scan the given expression tree for ungrouped variables (variables
1220 * that are not listed in the groupClauses list and are not within
1221 * the arguments of aggregate functions). Emit a suitable error message
1222 * if any are found.
1223 *
1224 * NOTE: we assume that the given clause has been transformed suitably for
1225 * parser output. This means we can use expression_tree_walker.
1226 *
1227 * NOTE: we recognize grouping expressions in the main query, but only
1228 * grouping Vars in subqueries. For example, this will be rejected,
1229 * although it could be allowed:
1230 * SELECT
1231 * (SELECT x FROM bar where y = (foo.a + foo.b))
1232 * FROM foo
1233 * GROUP BY a + b;
1234 * The difficulty is the need to account for different sublevels_up.
1235 * This appears to require a whole custom version of equal(), which is
1236 * way more pain than the feature seems worth.
1237 */
1238static void
1239check_ungrouped_columns(Node *node, ParseState *pstate, Query *qry,
1240 List *groupClauses, List *groupClauseCommonVars,
1241 bool have_non_var_grouping,
1242 List **func_grouped_rels)
1243{
1244 check_ungrouped_columns_context context;
1245
1246 context.pstate = pstate;
1247 context.qry = qry;
1248 context.hasJoinRTEs = false; /* assume caller flattened join Vars */
1249 context.groupClauses = groupClauses;
1250 context.groupClauseCommonVars = groupClauseCommonVars;
1251 context.have_non_var_grouping = have_non_var_grouping;
1252 context.func_grouped_rels = func_grouped_rels;
1253 context.sublevels_up = 0;
1254 context.in_agg_direct_args = false;
1255 check_ungrouped_columns_walker(node, &context);
1256}
1257
1258static bool
1259check_ungrouped_columns_walker(Node *node,
1260 check_ungrouped_columns_context *context)
1261{
1262 ListCell *gl;
1263
1264 if (node == NULL)
1265 return false;
1266 if (IsA(node, Const) ||
1267 IsA(node, Param))
1268 return false; /* constants are always acceptable */
1269
1270 if (IsA(node, Aggref))
1271 {
1272 Aggref *agg = (Aggref *) node;
1273
1274 if ((int) agg->agglevelsup == context->sublevels_up)
1275 {
1276 /*
1277 * If we find an aggregate call of the original level, do not
1278 * recurse into its normal arguments, ORDER BY arguments, or
1279 * filter; ungrouped vars there are not an error. But we should
1280 * check direct arguments as though they weren't in an aggregate.
1281 * We set a special flag in the context to help produce a useful
1282 * error message for ungrouped vars in direct arguments.
1283 */
1284 bool result;
1285
1286 Assert(!context->in_agg_direct_args);
1287 context->in_agg_direct_args = true;
1288 result = check_ungrouped_columns_walker((Node *) agg->aggdirectargs,
1289 context);
1290 context->in_agg_direct_args = false;
1291 return result;
1292 }
1293
1294 /*
1295 * We can skip recursing into aggregates of higher levels altogether,
1296 * since they could not possibly contain Vars of concern to us (see
1297 * transformAggregateCall). We do need to look at aggregates of lower
1298 * levels, however.
1299 */
1300 if ((int) agg->agglevelsup > context->sublevels_up)
1301 return false;
1302 }
1303
1304 if (IsA(node, GroupingFunc))
1305 {
1306 GroupingFunc *grp = (GroupingFunc *) node;
1307
1308 /* handled GroupingFunc separately, no need to recheck at this level */
1309
1310 if ((int) grp->agglevelsup >= context->sublevels_up)
1311 return false;
1312 }
1313
1314 /*
1315 * If we have any GROUP BY items that are not simple Vars, check to see if
1316 * subexpression as a whole matches any GROUP BY item. We need to do this
1317 * at every recursion level so that we recognize GROUPed-BY expressions
1318 * before reaching variables within them. But this only works at the outer
1319 * query level, as noted above.
1320 */
1321 if (context->have_non_var_grouping && context->sublevels_up == 0)
1322 {
1323 foreach(gl, context->groupClauses)
1324 {
1325 TargetEntry *tle = lfirst(gl);
1326
1327 if (equal(node, tle->expr))
1328 return false; /* acceptable, do not descend more */
1329 }
1330 }
1331
1332 /*
1333 * If we have an ungrouped Var of the original query level, we have a
1334 * failure. Vars below the original query level are not a problem, and
1335 * neither are Vars from above it. (If such Vars are ungrouped as far as
1336 * their own query level is concerned, that's someone else's problem...)
1337 */
1338 if (IsA(node, Var))
1339 {
1340 Var *var = (Var *) node;
1341 RangeTblEntry *rte;
1342 char *attname;
1343
1344 if (var->varlevelsup != context->sublevels_up)
1345 return false; /* it's not local to my query, ignore */
1346
1347 /*
1348 * Check for a match, if we didn't do it above.
1349 */
1350 if (!context->have_non_var_grouping || context->sublevels_up != 0)
1351 {
1352 foreach(gl, context->groupClauses)
1353 {
1354 Var *gvar = (Var *) ((TargetEntry *) lfirst(gl))->expr;
1355
1356 if (IsA(gvar, Var) &&
1357 gvar->varno == var->varno &&
1358 gvar->varattno == var->varattno &&
1359 gvar->varlevelsup == 0)
1360 return false; /* acceptable, we're okay */
1361 }
1362 }
1363
1364 /*
1365 * Check whether the Var is known functionally dependent on the GROUP
1366 * BY columns. If so, we can allow the Var to be used, because the
1367 * grouping is really a no-op for this table. However, this deduction
1368 * depends on one or more constraints of the table, so we have to add
1369 * those constraints to the query's constraintDeps list, because it's
1370 * not semantically valid anymore if the constraint(s) get dropped.
1371 * (Therefore, this check must be the last-ditch effort before raising
1372 * error: we don't want to add dependencies unnecessarily.)
1373 *
1374 * Because this is a pretty expensive check, and will have the same
1375 * outcome for all columns of a table, we remember which RTEs we've
1376 * already proven functional dependency for in the func_grouped_rels
1377 * list. This test also prevents us from adding duplicate entries to
1378 * the constraintDeps list.
1379 */
1380 if (list_member_int(*context->func_grouped_rels, var->varno))
1381 return false; /* previously proven acceptable */
1382
1383 Assert(var->varno > 0 &&
1384 (int) var->varno <= list_length(context->pstate->p_rtable));
1385 rte = rt_fetch(var->varno, context->pstate->p_rtable);
1386 if (rte->rtekind == RTE_RELATION)
1387 {
1388 if (check_functional_grouping(rte->relid,
1389 var->varno,
1390 0,
1391 context->groupClauseCommonVars,
1392 &context->qry->constraintDeps))
1393 {
1394 *context->func_grouped_rels =
1395 lappend_int(*context->func_grouped_rels, var->varno);
1396 return false; /* acceptable */
1397 }
1398 }
1399
1400 /* Found an ungrouped local variable; generate error message */
1401 attname = get_rte_attribute_name(rte, var->varattno);
1402 if (context->sublevels_up == 0)
1403 ereport(ERROR,
1404 (errcode(ERRCODE_GROUPING_ERROR),
1405 errmsg("column \"%s.%s\" must appear in the GROUP BY clause or be used in an aggregate function",
1406 rte->eref->aliasname, attname),
1407 context->in_agg_direct_args ?
1408 errdetail("Direct arguments of an ordered-set aggregate must use only grouped columns.") : 0,
1409 parser_errposition(context->pstate, var->location)));
1410 else
1411 ereport(ERROR,
1412 (errcode(ERRCODE_GROUPING_ERROR),
1413 errmsg("subquery uses ungrouped column \"%s.%s\" from outer query",
1414 rte->eref->aliasname, attname),
1415 parser_errposition(context->pstate, var->location)));
1416 }
1417
1418 if (IsA(node, Query))
1419 {
1420 /* Recurse into subselects */
1421 bool result;
1422
1423 context->sublevels_up++;
1424 result = query_tree_walker((Query *) node,
1425 check_ungrouped_columns_walker,
1426 (void *) context,
1427 0);
1428 context->sublevels_up--;
1429 return result;
1430 }
1431 return expression_tree_walker(node, check_ungrouped_columns_walker,
1432 (void *) context);
1433}
1434
1435/*
1436 * finalize_grouping_exprs -
1437 * Scan the given expression tree for GROUPING() and related calls,
1438 * and validate and process their arguments.
1439 *
1440 * This is split out from check_ungrouped_columns above because it needs
1441 * to modify the nodes (which it does in-place, not via a mutator) while
1442 * check_ungrouped_columns may see only a copy of the original thanks to
1443 * flattening of join alias vars. So here, we flatten each individual
1444 * GROUPING argument as we see it before comparing it.
1445 */
1446static void
1447finalize_grouping_exprs(Node *node, ParseState *pstate, Query *qry,
1448 List *groupClauses, bool hasJoinRTEs,
1449 bool have_non_var_grouping)
1450{
1451 check_ungrouped_columns_context context;
1452
1453 context.pstate = pstate;
1454 context.qry = qry;
1455 context.hasJoinRTEs = hasJoinRTEs;
1456 context.groupClauses = groupClauses;
1457 context.groupClauseCommonVars = NIL;
1458 context.have_non_var_grouping = have_non_var_grouping;
1459 context.func_grouped_rels = NULL;
1460 context.sublevels_up = 0;
1461 context.in_agg_direct_args = false;
1462 finalize_grouping_exprs_walker(node, &context);
1463}
1464
1465static bool
1466finalize_grouping_exprs_walker(Node *node,
1467 check_ungrouped_columns_context *context)
1468{
1469 ListCell *gl;
1470
1471 if (node == NULL)
1472 return false;
1473 if (IsA(node, Const) ||
1474 IsA(node, Param))
1475 return false; /* constants are always acceptable */
1476
1477 if (IsA(node, Aggref))
1478 {
1479 Aggref *agg = (Aggref *) node;
1480
1481 if ((int) agg->agglevelsup == context->sublevels_up)
1482 {
1483 /*
1484 * If we find an aggregate call of the original level, do not
1485 * recurse into its normal arguments, ORDER BY arguments, or
1486 * filter; GROUPING exprs of this level are not allowed there. But
1487 * check direct arguments as though they weren't in an aggregate.
1488 */
1489 bool result;
1490
1491 Assert(!context->in_agg_direct_args);
1492 context->in_agg_direct_args = true;
1493 result = finalize_grouping_exprs_walker((Node *) agg->aggdirectargs,
1494 context);
1495 context->in_agg_direct_args = false;
1496 return result;
1497 }
1498
1499 /*
1500 * We can skip recursing into aggregates of higher levels altogether,
1501 * since they could not possibly contain exprs of concern to us (see
1502 * transformAggregateCall). We do need to look at aggregates of lower
1503 * levels, however.
1504 */
1505 if ((int) agg->agglevelsup > context->sublevels_up)
1506 return false;
1507 }
1508
1509 if (IsA(node, GroupingFunc))
1510 {
1511 GroupingFunc *grp = (GroupingFunc *) node;
1512
1513 /*
1514 * We only need to check GroupingFunc nodes at the exact level to
1515 * which they belong, since they cannot mix levels in arguments.
1516 */
1517
1518 if ((int) grp->agglevelsup == context->sublevels_up)
1519 {
1520 ListCell *lc;
1521 List *ref_list = NIL;
1522
1523 foreach(lc, grp->args)
1524 {
1525 Node *expr = lfirst(lc);
1526 Index ref = 0;
1527
1528 if (context->hasJoinRTEs)
1529 expr = flatten_join_alias_vars(context->qry, expr);
1530
1531 /*
1532 * Each expression must match a grouping entry at the current
1533 * query level. Unlike the general expression case, we don't
1534 * allow functional dependencies or outer references.
1535 */
1536
1537 if (IsA(expr, Var))
1538 {
1539 Var *var = (Var *) expr;
1540
1541 if (var->varlevelsup == context->sublevels_up)
1542 {
1543 foreach(gl, context->groupClauses)
1544 {
1545 TargetEntry *tle = lfirst(gl);
1546 Var *gvar = (Var *) tle->expr;
1547
1548 if (IsA(gvar, Var) &&
1549 gvar->varno == var->varno &&
1550 gvar->varattno == var->varattno &&
1551 gvar->varlevelsup == 0)
1552 {
1553 ref = tle->ressortgroupref;
1554 break;
1555 }
1556 }
1557 }
1558 }
1559 else if (context->have_non_var_grouping &&
1560 context->sublevels_up == 0)
1561 {
1562 foreach(gl, context->groupClauses)
1563 {
1564 TargetEntry *tle = lfirst(gl);
1565
1566 if (equal(expr, tle->expr))
1567 {
1568 ref = tle->ressortgroupref;
1569 break;
1570 }
1571 }
1572 }
1573
1574 if (ref == 0)
1575 ereport(ERROR,
1576 (errcode(ERRCODE_GROUPING_ERROR),
1577 errmsg("arguments to GROUPING must be grouping expressions of the associated query level"),
1578 parser_errposition(context->pstate,
1579 exprLocation(expr))));
1580
1581 ref_list = lappend_int(ref_list, ref);
1582 }
1583
1584 grp->refs = ref_list;
1585 }
1586
1587 if ((int) grp->agglevelsup > context->sublevels_up)
1588 return false;
1589 }
1590
1591 if (IsA(node, Query))
1592 {
1593 /* Recurse into subselects */
1594 bool result;
1595
1596 context->sublevels_up++;
1597 result = query_tree_walker((Query *) node,
1598 finalize_grouping_exprs_walker,
1599 (void *) context,
1600 0);
1601 context->sublevels_up--;
1602 return result;
1603 }
1604 return expression_tree_walker(node, finalize_grouping_exprs_walker,
1605 (void *) context);
1606}
1607
1608
1609/*
1610 * Given a GroupingSet node, expand it and return a list of lists.
1611 *
1612 * For EMPTY nodes, return a list of one empty list.
1613 *
1614 * For SIMPLE nodes, return a list of one list, which is the node content.
1615 *
1616 * For CUBE and ROLLUP nodes, return a list of the expansions.
1617 *
1618 * For SET nodes, recursively expand contained CUBE and ROLLUP.
1619 */
1620static List *
1621expand_groupingset_node(GroupingSet *gs)
1622{
1623 List *result = NIL;
1624
1625 switch (gs->kind)
1626 {
1627 case GROUPING_SET_EMPTY:
1628 result = list_make1(NIL);
1629 break;
1630
1631 case GROUPING_SET_SIMPLE:
1632 result = list_make1(gs->content);
1633 break;
1634
1635 case GROUPING_SET_ROLLUP:
1636 {
1637 List *rollup_val = gs->content;
1638 ListCell *lc;
1639 int curgroup_size = list_length(gs->content);
1640
1641 while (curgroup_size > 0)
1642 {
1643 List *current_result = NIL;
1644 int i = curgroup_size;
1645
1646 foreach(lc, rollup_val)
1647 {
1648 GroupingSet *gs_current = (GroupingSet *) lfirst(lc);
1649
1650 Assert(gs_current->kind == GROUPING_SET_SIMPLE);
1651
1652 current_result
1653 = list_concat(current_result,
1654 list_copy(gs_current->content));
1655
1656 /* If we are done with making the current group, break */
1657 if (--i == 0)
1658 break;
1659 }
1660
1661 result = lappend(result, current_result);
1662 --curgroup_size;
1663 }
1664
1665 result = lappend(result, NIL);
1666 }
1667 break;
1668
1669 case GROUPING_SET_CUBE:
1670 {
1671 List *cube_list = gs->content;
1672 int number_bits = list_length(cube_list);
1673 uint32 num_sets;
1674 uint32 i;
1675
1676 /* parser should cap this much lower */
1677 Assert(number_bits < 31);
1678
1679 num_sets = (1U << number_bits);
1680
1681 for (i = 0; i < num_sets; i++)
1682 {
1683 List *current_result = NIL;
1684 ListCell *lc;
1685 uint32 mask = 1U;
1686
1687 foreach(lc, cube_list)
1688 {
1689 GroupingSet *gs_current = (GroupingSet *) lfirst(lc);
1690
1691 Assert(gs_current->kind == GROUPING_SET_SIMPLE);
1692
1693 if (mask & i)
1694 {
1695 current_result
1696 = list_concat(current_result,
1697 list_copy(gs_current->content));
1698 }
1699
1700 mask <<= 1;
1701 }
1702
1703 result = lappend(result, current_result);
1704 }
1705 }
1706 break;
1707
1708 case GROUPING_SET_SETS:
1709 {
1710 ListCell *lc;
1711
1712 foreach(lc, gs->content)
1713 {
1714 List *current_result = expand_groupingset_node(lfirst(lc));
1715
1716 result = list_concat(result, current_result);
1717 }
1718 }
1719 break;
1720 }
1721
1722 return result;
1723}
1724
1725static int
1726cmp_list_len_asc(const void *a, const void *b)
1727{
1728 int la = list_length(*(List *const *) a);
1729 int lb = list_length(*(List *const *) b);
1730
1731 return (la > lb) ? 1 : (la == lb) ? 0 : -1;
1732}
1733
1734/*
1735 * Expand a groupingSets clause to a flat list of grouping sets.
1736 * The returned list is sorted by length, shortest sets first.
1737 *
1738 * This is mainly for the planner, but we use it here too to do
1739 * some consistency checks.
1740 */
1741List *
1742expand_grouping_sets(List *groupingSets, int limit)
1743{
1744 List *expanded_groups = NIL;
1745 List *result = NIL;
1746 double numsets = 1;
1747 ListCell *lc;
1748
1749 if (groupingSets == NIL)
1750 return NIL;
1751
1752 foreach(lc, groupingSets)
1753 {
1754 List *current_result = NIL;
1755 GroupingSet *gs = lfirst(lc);
1756
1757 current_result = expand_groupingset_node(gs);
1758
1759 Assert(current_result != NIL);
1760
1761 numsets *= list_length(current_result);
1762
1763 if (limit >= 0 && numsets > limit)
1764 return NIL;
1765
1766 expanded_groups = lappend(expanded_groups, current_result);
1767 }
1768
1769 /*
1770 * Do cartesian product between sublists of expanded_groups. While at it,
1771 * remove any duplicate elements from individual grouping sets (we must
1772 * NOT change the number of sets though)
1773 */
1774
1775 foreach(lc, (List *) linitial(expanded_groups))
1776 {
1777 result = lappend(result, list_union_int(NIL, (List *) lfirst(lc)));
1778 }
1779
1780 for_each_cell(lc, lnext(list_head(expanded_groups)))
1781 {
1782 List *p = lfirst(lc);
1783 List *new_result = NIL;
1784 ListCell *lc2;
1785
1786 foreach(lc2, result)
1787 {
1788 List *q = lfirst(lc2);
1789 ListCell *lc3;
1790
1791 foreach(lc3, p)
1792 {
1793 new_result = lappend(new_result,
1794 list_union_int(q, (List *) lfirst(lc3)));
1795 }
1796 }
1797 result = new_result;
1798 }
1799
1800 if (list_length(result) > 1)
1801 {
1802 int result_len = list_length(result);
1803 List **buf = palloc(sizeof(List *) * result_len);
1804 List **ptr = buf;
1805
1806 foreach(lc, result)
1807 {
1808 *ptr++ = lfirst(lc);
1809 }
1810
1811 qsort(buf, result_len, sizeof(List *), cmp_list_len_asc);
1812
1813 result = NIL;
1814 ptr = buf;
1815
1816 while (result_len-- > 0)
1817 result = lappend(result, *ptr++);
1818
1819 pfree(buf);
1820 }
1821
1822 return result;
1823}
1824
1825/*
1826 * get_aggregate_argtypes
1827 * Identify the specific datatypes passed to an aggregate call.
1828 *
1829 * Given an Aggref, extract the actual datatypes of the input arguments.
1830 * The input datatypes are reported in a way that matches up with the
1831 * aggregate's declaration, ie, any ORDER BY columns attached to a plain
1832 * aggregate are ignored, but we report both direct and aggregated args of
1833 * an ordered-set aggregate.
1834 *
1835 * Datatypes are returned into inputTypes[], which must reference an array
1836 * of length FUNC_MAX_ARGS.
1837 *
1838 * The function result is the number of actual arguments.
1839 */
1840int
1841get_aggregate_argtypes(Aggref *aggref, Oid *inputTypes)
1842{
1843 int numArguments = 0;
1844 ListCell *lc;
1845
1846 Assert(list_length(aggref->aggargtypes) <= FUNC_MAX_ARGS);
1847
1848 foreach(lc, aggref->aggargtypes)
1849 {
1850 inputTypes[numArguments++] = lfirst_oid(lc);
1851 }
1852
1853 return numArguments;
1854}
1855
1856/*
1857 * resolve_aggregate_transtype
1858 * Identify the transition state value's datatype for an aggregate call.
1859 *
1860 * This function resolves a polymorphic aggregate's state datatype.
1861 * It must be passed the aggtranstype from the aggregate's catalog entry,
1862 * as well as the actual argument types extracted by get_aggregate_argtypes.
1863 * (We could fetch pg_aggregate.aggtranstype internally, but all existing
1864 * callers already have the value at hand, so we make them pass it.)
1865 */
1866Oid
1867resolve_aggregate_transtype(Oid aggfuncid,
1868 Oid aggtranstype,
1869 Oid *inputTypes,
1870 int numArguments)
1871{
1872 /* resolve actual type of transition state, if polymorphic */
1873 if (IsPolymorphicType(aggtranstype))
1874 {
1875 /* have to fetch the agg's declared input types... */
1876 Oid *declaredArgTypes;
1877 int agg_nargs;
1878
1879 (void) get_func_signature(aggfuncid, &declaredArgTypes, &agg_nargs);
1880
1881 /*
1882 * VARIADIC ANY aggs could have more actual than declared args, but
1883 * such extra args can't affect polymorphic type resolution.
1884 */
1885 Assert(agg_nargs <= numArguments);
1886
1887 aggtranstype = enforce_generic_type_consistency(inputTypes,
1888 declaredArgTypes,
1889 agg_nargs,
1890 aggtranstype,
1891 false);
1892 pfree(declaredArgTypes);
1893 }
1894 return aggtranstype;
1895}
1896
1897/*
1898 * Create an expression tree for the transition function of an aggregate.
1899 * This is needed so that polymorphic functions can be used within an
1900 * aggregate --- without the expression tree, such functions would not know
1901 * the datatypes they are supposed to use. (The trees will never actually
1902 * be executed, however, so we can skimp a bit on correctness.)
1903 *
1904 * agg_input_types and agg_state_type identifies the input types of the
1905 * aggregate. These should be resolved to actual types (ie, none should
1906 * ever be ANYELEMENT etc).
1907 * agg_input_collation is the aggregate function's input collation.
1908 *
1909 * For an ordered-set aggregate, remember that agg_input_types describes
1910 * the direct arguments followed by the aggregated arguments.
1911 *
1912 * transfn_oid and invtransfn_oid identify the funcs to be called; the
1913 * latter may be InvalidOid, however if invtransfn_oid is set then
1914 * transfn_oid must also be set.
1915 *
1916 * Pointers to the constructed trees are returned into *transfnexpr,
1917 * *invtransfnexpr. If there is no invtransfn, the respective pointer is set
1918 * to NULL. Since use of the invtransfn is optional, NULL may be passed for
1919 * invtransfnexpr.
1920 */
1921void
1922build_aggregate_transfn_expr(Oid *agg_input_types,
1923 int agg_num_inputs,
1924 int agg_num_direct_inputs,
1925 bool agg_variadic,
1926 Oid agg_state_type,
1927 Oid agg_input_collation,
1928 Oid transfn_oid,
1929 Oid invtransfn_oid,
1930 Expr **transfnexpr,
1931 Expr **invtransfnexpr)
1932{
1933 List *args;
1934 FuncExpr *fexpr;
1935 int i;
1936
1937 /*
1938 * Build arg list to use in the transfn FuncExpr node.
1939 */
1940 args = list_make1(make_agg_arg(agg_state_type, agg_input_collation));
1941
1942 for (i = agg_num_direct_inputs; i < agg_num_inputs; i++)
1943 {
1944 args = lappend(args,
1945 make_agg_arg(agg_input_types[i], agg_input_collation));
1946 }
1947
1948 fexpr = makeFuncExpr(transfn_oid,
1949 agg_state_type,
1950 args,
1951 InvalidOid,
1952 agg_input_collation,
1953 COERCE_EXPLICIT_CALL);
1954 fexpr->funcvariadic = agg_variadic;
1955 *transfnexpr = (Expr *) fexpr;
1956
1957 /*
1958 * Build invtransfn expression if requested, with same args as transfn
1959 */
1960 if (invtransfnexpr != NULL)
1961 {
1962 if (OidIsValid(invtransfn_oid))
1963 {
1964 fexpr = makeFuncExpr(invtransfn_oid,
1965 agg_state_type,
1966 args,
1967 InvalidOid,
1968 agg_input_collation,
1969 COERCE_EXPLICIT_CALL);
1970 fexpr->funcvariadic = agg_variadic;
1971 *invtransfnexpr = (Expr *) fexpr;
1972 }
1973 else
1974 *invtransfnexpr = NULL;
1975 }
1976}
1977
1978/*
1979 * Like build_aggregate_transfn_expr, but creates an expression tree for the
1980 * combine function of an aggregate, rather than the transition function.
1981 */
1982void
1983build_aggregate_combinefn_expr(Oid agg_state_type,
1984 Oid agg_input_collation,
1985 Oid combinefn_oid,
1986 Expr **combinefnexpr)
1987{
1988 Node *argp;
1989 List *args;
1990 FuncExpr *fexpr;
1991
1992 /* combinefn takes two arguments of the aggregate state type */
1993 argp = make_agg_arg(agg_state_type, agg_input_collation);
1994
1995 args = list_make2(argp, argp);
1996
1997 fexpr = makeFuncExpr(combinefn_oid,
1998 agg_state_type,
1999 args,
2000 InvalidOid,
2001 agg_input_collation,
2002 COERCE_EXPLICIT_CALL);
2003 /* combinefn is currently never treated as variadic */
2004 *combinefnexpr = (Expr *) fexpr;
2005}
2006
2007/*
2008 * Like build_aggregate_transfn_expr, but creates an expression tree for the
2009 * serialization function of an aggregate.
2010 */
2011void
2012build_aggregate_serialfn_expr(Oid serialfn_oid,
2013 Expr **serialfnexpr)
2014{
2015 List *args;
2016 FuncExpr *fexpr;
2017
2018 /* serialfn always takes INTERNAL and returns BYTEA */
2019 args = list_make1(make_agg_arg(INTERNALOID, InvalidOid));
2020
2021 fexpr = makeFuncExpr(serialfn_oid,
2022 BYTEAOID,
2023 args,
2024 InvalidOid,
2025 InvalidOid,
2026 COERCE_EXPLICIT_CALL);
2027 *serialfnexpr = (Expr *) fexpr;
2028}
2029
2030/*
2031 * Like build_aggregate_transfn_expr, but creates an expression tree for the
2032 * deserialization function of an aggregate.
2033 */
2034void
2035build_aggregate_deserialfn_expr(Oid deserialfn_oid,
2036 Expr **deserialfnexpr)
2037{
2038 List *args;
2039 FuncExpr *fexpr;
2040
2041 /* deserialfn always takes BYTEA, INTERNAL and returns INTERNAL */
2042 args = list_make2(make_agg_arg(BYTEAOID, InvalidOid),
2043 make_agg_arg(INTERNALOID, InvalidOid));
2044
2045 fexpr = makeFuncExpr(deserialfn_oid,
2046 INTERNALOID,
2047 args,
2048 InvalidOid,
2049 InvalidOid,
2050 COERCE_EXPLICIT_CALL);
2051 *deserialfnexpr = (Expr *) fexpr;
2052}
2053
2054/*
2055 * Like build_aggregate_transfn_expr, but creates an expression tree for the
2056 * final function of an aggregate, rather than the transition function.
2057 */
2058void
2059build_aggregate_finalfn_expr(Oid *agg_input_types,
2060 int num_finalfn_inputs,
2061 Oid agg_state_type,
2062 Oid agg_result_type,
2063 Oid agg_input_collation,
2064 Oid finalfn_oid,
2065 Expr **finalfnexpr)
2066{
2067 List *args;
2068 int i;
2069
2070 /*
2071 * Build expr tree for final function
2072 */
2073 args = list_make1(make_agg_arg(agg_state_type, agg_input_collation));
2074
2075 /* finalfn may take additional args, which match agg's input types */
2076 for (i = 0; i < num_finalfn_inputs - 1; i++)
2077 {
2078 args = lappend(args,
2079 make_agg_arg(agg_input_types[i], agg_input_collation));
2080 }
2081
2082 *finalfnexpr = (Expr *) makeFuncExpr(finalfn_oid,
2083 agg_result_type,
2084 args,
2085 InvalidOid,
2086 agg_input_collation,
2087 COERCE_EXPLICIT_CALL);
2088 /* finalfn is currently never treated as variadic */
2089}
2090
2091/*
2092 * Convenience function to build dummy argument expressions for aggregates.
2093 *
2094 * We really only care that an aggregate support function can discover its
2095 * actual argument types at runtime using get_fn_expr_argtype(), so it's okay
2096 * to use Param nodes that don't correspond to any real Param.
2097 */
2098static Node *
2099make_agg_arg(Oid argtype, Oid argcollation)
2100{
2101 Param *argp = makeNode(Param);
2102
2103 argp->paramkind = PARAM_EXEC;
2104 argp->paramid = -1;
2105 argp->paramtype = argtype;
2106 argp->paramtypmod = -1;
2107 argp->paramcollid = argcollation;
2108 argp->location = -1;
2109 return (Node *) argp;
2110}
2111