/*------------------------------------------------------------------------- * * parse_agg.c * handle aggregates and window functions in parser * * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * src/backend/parser/parse_agg.c * *------------------------------------------------------------------------- */ #include "postgres.h" #include "access/htup_details.h" #include "catalog/pg_aggregate.h" #include "catalog/pg_constraint.h" #include "catalog/pg_type.h" #include "common/int.h" #include "nodes/makefuncs.h" #include "nodes/nodeFuncs.h" #include "optimizer/optimizer.h" #include "parser/parse_agg.h" #include "parser/parse_clause.h" #include "parser/parse_coerce.h" #include "parser/parse_expr.h" #include "parser/parsetree.h" #include "rewrite/rewriteManip.h" #include "utils/builtins.h" #include "utils/lsyscache.h" #include "utils/syscache.h" typedef struct { ParseState *pstate; int min_varlevel; int min_agglevel; int sublevels_up; } check_agg_arguments_context; typedef struct { ParseState *pstate; Query *qry; bool hasJoinRTEs; List *groupClauses; List *groupClauseCommonVars; bool have_non_var_grouping; List **func_grouped_rels; int sublevels_up; bool in_agg_direct_args; } check_ungrouped_columns_context; static int check_agg_arguments(ParseState *pstate, List *directargs, List *args, Expr *filter); static bool check_agg_arguments_walker(Node *node, check_agg_arguments_context *context); static void check_ungrouped_columns(Node *node, ParseState *pstate, Query *qry, List *groupClauses, List *groupClauseCommonVars, bool have_non_var_grouping, List **func_grouped_rels); static bool check_ungrouped_columns_walker(Node *node, check_ungrouped_columns_context *context); static void finalize_grouping_exprs(Node *node, ParseState *pstate, Query *qry, List *groupClauses, bool hasJoinRTEs, bool have_non_var_grouping); static bool finalize_grouping_exprs_walker(Node *node, check_ungrouped_columns_context *context); static void check_agglevels_and_constraints(ParseState *pstate, Node *expr); static List *expand_groupingset_node(GroupingSet *gs); static Node *make_agg_arg(Oid argtype, Oid argcollation); /* * transformAggregateCall - * Finish initial transformation of an aggregate call * * parse_func.c has recognized the function as an aggregate, and has set up * all the fields of the Aggref except aggargtypes, aggdirectargs, args, * aggorder, aggdistinct and agglevelsup. The passed-in args list has been * through standard expression transformation and type coercion to match the * agg's declared arg types, while the passed-in aggorder list hasn't been * transformed at all. * * Here we separate the args list into direct and aggregated args, storing the * former in agg->aggdirectargs and the latter in agg->args. The regular * args, but not the direct args, are converted into a targetlist by inserting * TargetEntry nodes. We then transform the aggorder and agg_distinct * specifications to produce lists of SortGroupClause nodes for agg->aggorder * and agg->aggdistinct. (For a regular aggregate, this might result in * adding resjunk expressions to the targetlist; but for ordered-set * aggregates the aggorder list will always be one-to-one with the aggregated * args.) * * We must also determine which query level the aggregate actually belongs to, * set agglevelsup accordingly, and mark p_hasAggs true in the corresponding * pstate level. */ void transformAggregateCall(ParseState *pstate, Aggref *agg, List *args, List *aggorder, bool agg_distinct) { List *argtypes = NIL; List *tlist = NIL; List *torder = NIL; List *tdistinct = NIL; AttrNumber attno = 1; int save_next_resno; ListCell *lc; if (AGGKIND_IS_ORDERED_SET(agg->aggkind)) { /* * For an ordered-set agg, the args list includes direct args and * aggregated args; we must split them apart. */ int numDirectArgs = list_length(args) - list_length(aggorder); List *aargs; ListCell *lc2; Assert(numDirectArgs >= 0); aargs = list_copy_tail(args, numDirectArgs); agg->aggdirectargs = list_truncate(args, numDirectArgs); /* * Build a tlist from the aggregated args, and make a sortlist entry * for each one. Note that the expressions in the SortBy nodes are * ignored (they are the raw versions of the transformed args); we are * just looking at the sort information in the SortBy nodes. */ forboth(lc, aargs, lc2, aggorder) { Expr *arg = (Expr *) lfirst(lc); SortBy *sortby = (SortBy *) lfirst(lc2); TargetEntry *tle; /* We don't bother to assign column names to the entries */ tle = makeTargetEntry(arg, attno++, NULL, false); tlist = lappend(tlist, tle); torder = addTargetToSortList(pstate, tle, torder, tlist, sortby); } /* Never any DISTINCT in an ordered-set agg */ Assert(!agg_distinct); } else { /* Regular aggregate, so it has no direct args */ agg->aggdirectargs = NIL; /* * Transform the plain list of Exprs into a targetlist. */ foreach(lc, args) { Expr *arg = (Expr *) lfirst(lc); TargetEntry *tle; /* We don't bother to assign column names to the entries */ tle = makeTargetEntry(arg, attno++, NULL, false); tlist = lappend(tlist, tle); } /* * If we have an ORDER BY, transform it. This will add columns to the * tlist if they appear in ORDER BY but weren't already in the arg * list. They will be marked resjunk = true so we can tell them apart * from regular aggregate arguments later. * * We need to mess with p_next_resno since it will be used to number * any new targetlist entries. */ save_next_resno = pstate->p_next_resno; pstate->p_next_resno = attno; torder = transformSortClause(pstate, aggorder, &tlist, EXPR_KIND_ORDER_BY, true /* force SQL99 rules */ ); /* * If we have DISTINCT, transform that to produce a distinctList. */ if (agg_distinct) { tdistinct = transformDistinctClause(pstate, &tlist, torder, true); /* * Remove this check if executor support for hashed distinct for * aggregates is ever added. */ foreach(lc, tdistinct) { SortGroupClause *sortcl = (SortGroupClause *) lfirst(lc); if (!OidIsValid(sortcl->sortop)) { Node *expr = get_sortgroupclause_expr(sortcl, tlist); ereport(ERROR, (errcode(ERRCODE_UNDEFINED_FUNCTION), errmsg("could not identify an ordering operator for type %s", format_type_be(exprType(expr))), errdetail("Aggregates with DISTINCT must be able to sort their inputs."), parser_errposition(pstate, exprLocation(expr)))); } } } pstate->p_next_resno = save_next_resno; } /* Update the Aggref with the transformation results */ agg->args = tlist; agg->aggorder = torder; agg->aggdistinct = tdistinct; /* * Now build the aggargtypes list with the type OIDs of the direct and * aggregated args, ignoring any resjunk entries that might have been * added by ORDER BY/DISTINCT processing. We can't do this earlier * because said processing can modify some args' data types, in particular * by resolving previously-unresolved "unknown" literals. */ foreach(lc, agg->aggdirectargs) { Expr *arg = (Expr *) lfirst(lc); argtypes = lappend_oid(argtypes, exprType((Node *) arg)); } foreach(lc, tlist) { TargetEntry *tle = (TargetEntry *) lfirst(lc); if (tle->resjunk) continue; /* ignore junk */ argtypes = lappend_oid(argtypes, exprType((Node *) tle->expr)); } agg->aggargtypes = argtypes; check_agglevels_and_constraints(pstate, (Node *) agg); } /* * transformGroupingFunc * Transform a GROUPING expression * * GROUPING() behaves very like an aggregate. Processing of levels and nesting * is done as for aggregates. We set p_hasAggs for these expressions too. */ Node * transformGroupingFunc(ParseState *pstate, GroupingFunc *p) { ListCell *lc; List *args = p->args; List *result_list = NIL; GroupingFunc *result = makeNode(GroupingFunc); if (list_length(args) > 31) ereport(ERROR, (errcode(ERRCODE_TOO_MANY_ARGUMENTS), errmsg("GROUPING must have fewer than 32 arguments"), parser_errposition(pstate, p->location))); foreach(lc, args) { Node *current_result; current_result = transformExpr(pstate, (Node *) lfirst(lc), pstate->p_expr_kind); /* acceptability of expressions is checked later */ result_list = lappend(result_list, current_result); } result->args = result_list; result->location = p->location; check_agglevels_and_constraints(pstate, (Node *) result); return (Node *) result; } /* * Aggregate functions and grouping operations (which are combined in the spec * as ) are very similar with regard to level and * nesting restrictions (though we allow a lot more things than the spec does). * Centralise those restrictions here. */ static void check_agglevels_and_constraints(ParseState *pstate, Node *expr) { List *directargs = NIL; List *args = NIL; Expr *filter = NULL; int min_varlevel; int location = -1; Index *p_levelsup; const char *err; bool errkind; bool isAgg = IsA(expr, Aggref); if (isAgg) { Aggref *agg = (Aggref *) expr; directargs = agg->aggdirectargs; args = agg->args; filter = agg->aggfilter; location = agg->location; p_levelsup = &agg->agglevelsup; } else { GroupingFunc *grp = (GroupingFunc *) expr; args = grp->args; location = grp->location; p_levelsup = &grp->agglevelsup; } /* * Check the arguments to compute the aggregate's level and detect * improper nesting. */ min_varlevel = check_agg_arguments(pstate, directargs, args, filter); *p_levelsup = min_varlevel; /* Mark the correct pstate level as having aggregates */ while (min_varlevel-- > 0) pstate = pstate->parentParseState; pstate->p_hasAggs = true; /* * Check to see if the aggregate function is in an invalid place within * its aggregation query. * * For brevity we support two schemes for reporting an error here: set * "err" to a custom message, or set "errkind" true if the error context * is sufficiently identified by what ParseExprKindName will return, *and* * what it will return is just a SQL keyword. (Otherwise, use a custom * message to avoid creating translation problems.) */ err = NULL; errkind = false; switch (pstate->p_expr_kind) { case EXPR_KIND_NONE: Assert(false); /* can't happen */ break; case EXPR_KIND_OTHER: /* * Accept aggregate/grouping here; caller must throw error if * wanted */ break; case EXPR_KIND_JOIN_ON: case EXPR_KIND_JOIN_USING: if (isAgg) err = _("aggregate functions are not allowed in JOIN conditions"); else err = _("grouping operations are not allowed in JOIN conditions"); break; case EXPR_KIND_FROM_SUBSELECT: /* Should only be possible in a LATERAL subquery */ Assert(pstate->p_lateral_active); /* * Aggregate/grouping scope rules make it worth being explicit * here */ if (isAgg) err = _("aggregate functions are not allowed in FROM clause of their own query level"); else err = _("grouping operations are not allowed in FROM clause of their own query level"); break; case EXPR_KIND_FROM_FUNCTION: if (isAgg) err = _("aggregate functions are not allowed in functions in FROM"); else err = _("grouping operations are not allowed in functions in FROM"); break; case EXPR_KIND_WHERE: errkind = true; break; case EXPR_KIND_POLICY: if (isAgg) err = _("aggregate functions are not allowed in policy expressions"); else err = _("grouping operations are not allowed in policy expressions"); break; case EXPR_KIND_HAVING: /* okay */ break; case EXPR_KIND_FILTER: errkind = true; break; case EXPR_KIND_WINDOW_PARTITION: /* okay */ break; case EXPR_KIND_WINDOW_ORDER: /* okay */ break; case EXPR_KIND_WINDOW_FRAME_RANGE: if (isAgg) err = _("aggregate functions are not allowed in window RANGE"); else err = _("grouping operations are not allowed in window RANGE"); break; case EXPR_KIND_WINDOW_FRAME_ROWS: if (isAgg) err = _("aggregate functions are not allowed in window ROWS"); else err = _("grouping operations are not allowed in window ROWS"); break; case EXPR_KIND_WINDOW_FRAME_GROUPS: if (isAgg) err = _("aggregate functions are not allowed in window GROUPS"); else err = _("grouping operations are not allowed in window GROUPS"); break; case EXPR_KIND_SELECT_TARGET: /* okay */ break; case EXPR_KIND_INSERT_TARGET: case EXPR_KIND_UPDATE_SOURCE: case EXPR_KIND_UPDATE_TARGET: errkind = true; break; case EXPR_KIND_MERGE_WHEN: if (isAgg) err = _("aggregate functions are not allowed in MERGE WHEN conditions"); else err = _("grouping operations are not allowed in MERGE WHEN conditions"); break; case EXPR_KIND_GROUP_BY: errkind = true; break; case EXPR_KIND_ORDER_BY: /* okay */ break; case EXPR_KIND_DISTINCT_ON: /* okay */ break; case EXPR_KIND_LIMIT: case EXPR_KIND_OFFSET: errkind = true; break; case EXPR_KIND_RETURNING: errkind = true; break; case EXPR_KIND_VALUES: case EXPR_KIND_VALUES_SINGLE: errkind = true; break; case EXPR_KIND_CHECK_CONSTRAINT: case EXPR_KIND_DOMAIN_CHECK: if (isAgg) err = _("aggregate functions are not allowed in check constraints"); else err = _("grouping operations are not allowed in check constraints"); break; case EXPR_KIND_COLUMN_DEFAULT: case EXPR_KIND_FUNCTION_DEFAULT: if (isAgg) err = _("aggregate functions are not allowed in DEFAULT expressions"); else err = _("grouping operations are not allowed in DEFAULT expressions"); break; case EXPR_KIND_INDEX_EXPRESSION: if (isAgg) err = _("aggregate functions are not allowed in index expressions"); else err = _("grouping operations are not allowed in index expressions"); break; case EXPR_KIND_INDEX_PREDICATE: if (isAgg) err = _("aggregate functions are not allowed in index predicates"); else err = _("grouping operations are not allowed in index predicates"); break; case EXPR_KIND_STATS_EXPRESSION: if (isAgg) err = _("aggregate functions are not allowed in statistics expressions"); else err = _("grouping operations are not allowed in statistics expressions"); break; case EXPR_KIND_ALTER_COL_TRANSFORM: if (isAgg) err = _("aggregate functions are not allowed in transform expressions"); else err = _("grouping operations are not allowed in transform expressions"); break; case EXPR_KIND_EXECUTE_PARAMETER: if (isAgg) err = _("aggregate functions are not allowed in EXECUTE parameters"); else err = _("grouping operations are not allowed in EXECUTE parameters"); break; case EXPR_KIND_TRIGGER_WHEN: if (isAgg) err = _("aggregate functions are not allowed in trigger WHEN conditions"); else err = _("grouping operations are not allowed in trigger WHEN conditions"); break; case EXPR_KIND_PARTITION_BOUND: if (isAgg) err = _("aggregate functions are not allowed in partition bound"); else err = _("grouping operations are not allowed in partition bound"); break; case EXPR_KIND_PARTITION_EXPRESSION: if (isAgg) err = _("aggregate functions are not allowed in partition key expressions"); else err = _("grouping operations are not allowed in partition key expressions"); break; case EXPR_KIND_GENERATED_COLUMN: if (isAgg) err = _("aggregate functions are not allowed in column generation expressions"); else err = _("grouping operations are not allowed in column generation expressions"); break; case EXPR_KIND_CALL_ARGUMENT: if (isAgg) err = _("aggregate functions are not allowed in CALL arguments"); else err = _("grouping operations are not allowed in CALL arguments"); break; case EXPR_KIND_COPY_WHERE: if (isAgg) err = _("aggregate functions are not allowed in COPY FROM WHERE conditions"); else err = _("grouping operations are not allowed in COPY FROM WHERE conditions"); break; case EXPR_KIND_CYCLE_MARK: errkind = true; break; /* * There is intentionally no default: case here, so that the * compiler will warn if we add a new ParseExprKind without * extending this switch. If we do see an unrecognized value at * runtime, the behavior will be the same as for EXPR_KIND_OTHER, * which is sane anyway. */ } if (err) ereport(ERROR, (errcode(ERRCODE_GROUPING_ERROR), errmsg_internal("%s", err), parser_errposition(pstate, location))); if (errkind) { if (isAgg) /* translator: %s is name of a SQL construct, eg GROUP BY */ err = _("aggregate functions are not allowed in %s"); else /* translator: %s is name of a SQL construct, eg GROUP BY */ err = _("grouping operations are not allowed in %s"); ereport(ERROR, (errcode(ERRCODE_GROUPING_ERROR), errmsg_internal(err, ParseExprKindName(pstate->p_expr_kind)), parser_errposition(pstate, location))); } } /* * check_agg_arguments * Scan the arguments of an aggregate function to determine the * aggregate's semantic level (zero is the current select's level, * one is its parent, etc). * * The aggregate's level is the same as the level of the lowest-level variable * or aggregate in its aggregated arguments (including any ORDER BY columns) * or filter expression; or if it contains no variables at all, we presume it * to be local. * * Vars/Aggs in direct arguments are *not* counted towards determining the * agg's level, as those arguments aren't evaluated per-row but only * per-group, and so in some sense aren't really agg arguments. However, * this can mean that we decide an agg is upper-level even when its direct * args contain lower-level Vars/Aggs, and that case has to be disallowed. * (This is a little strange, but the SQL standard seems pretty definite that * direct args are not to be considered when setting the agg's level.) * * We also take this opportunity to detect any aggregates or window functions * nested within the arguments. We can throw error immediately if we find * a window function. Aggregates are a bit trickier because it's only an * error if the inner aggregate is of the same semantic level as the outer, * which we can't know until we finish scanning the arguments. */ static int check_agg_arguments(ParseState *pstate, List *directargs, List *args, Expr *filter) { int agglevel; check_agg_arguments_context context; context.pstate = pstate; context.min_varlevel = -1; /* signifies nothing found yet */ context.min_agglevel = -1; context.sublevels_up = 0; (void) check_agg_arguments_walker((Node *) args, &context); (void) check_agg_arguments_walker((Node *) filter, &context); /* * If we found no vars nor aggs at all, it's a level-zero aggregate; * otherwise, its level is the minimum of vars or aggs. */ if (context.min_varlevel < 0) { if (context.min_agglevel < 0) agglevel = 0; else agglevel = context.min_agglevel; } else if (context.min_agglevel < 0) agglevel = context.min_varlevel; else agglevel = Min(context.min_varlevel, context.min_agglevel); /* * If there's a nested aggregate of the same semantic level, complain. */ if (agglevel == context.min_agglevel) { int aggloc; aggloc = locate_agg_of_level((Node *) args, agglevel); if (aggloc < 0) aggloc = locate_agg_of_level((Node *) filter, agglevel); ereport(ERROR, (errcode(ERRCODE_GROUPING_ERROR), errmsg("aggregate function calls cannot be nested"), parser_errposition(pstate, aggloc))); } /* * Now check for vars/aggs in the direct arguments, and throw error if * needed. Note that we allow a Var of the agg's semantic level, but not * an Agg of that level. In principle such Aggs could probably be * supported, but it would create an ordering dependency among the * aggregates at execution time. Since the case appears neither to be * required by spec nor particularly useful, we just treat it as a * nested-aggregate situation. */ if (directargs) { context.min_varlevel = -1; context.min_agglevel = -1; (void) check_agg_arguments_walker((Node *) directargs, &context); if (context.min_varlevel >= 0 && context.min_varlevel < agglevel) ereport(ERROR, (errcode(ERRCODE_GROUPING_ERROR), errmsg("outer-level aggregate cannot contain a lower-level variable in its direct arguments"), parser_errposition(pstate, locate_var_of_level((Node *) directargs, context.min_varlevel)))); if (context.min_agglevel >= 0 && context.min_agglevel <= agglevel) ereport(ERROR, (errcode(ERRCODE_GROUPING_ERROR), errmsg("aggregate function calls cannot be nested"), parser_errposition(pstate, locate_agg_of_level((Node *) directargs, context.min_agglevel)))); } return agglevel; } static bool check_agg_arguments_walker(Node *node, check_agg_arguments_context *context) { if (node == NULL) return false; if (IsA(node, Var)) { int varlevelsup = ((Var *) node)->varlevelsup; /* convert levelsup to frame of reference of original query */ varlevelsup -= context->sublevels_up; /* ignore local vars of subqueries */ if (varlevelsup >= 0) { if (context->min_varlevel < 0 || context->min_varlevel > varlevelsup) context->min_varlevel = varlevelsup; } return false; } if (IsA(node, Aggref)) { int agglevelsup = ((Aggref *) node)->agglevelsup; /* convert levelsup to frame of reference of original query */ agglevelsup -= context->sublevels_up; /* ignore local aggs of subqueries */ if (agglevelsup >= 0) { if (context->min_agglevel < 0 || context->min_agglevel > agglevelsup) context->min_agglevel = agglevelsup; } /* Continue and descend into subtree */ } if (IsA(node, GroupingFunc)) { int agglevelsup = ((GroupingFunc *) node)->agglevelsup; /* convert levelsup to frame of reference of original query */ agglevelsup -= context->sublevels_up; /* ignore local aggs of subqueries */ if (agglevelsup >= 0) { if (context->min_agglevel < 0 || context->min_agglevel > agglevelsup) context->min_agglevel = agglevelsup; } /* Continue and descend into subtree */ } /* * SRFs and window functions can be rejected immediately, unless we are * within a sub-select within the aggregate's arguments; in that case * they're OK. */ if (context->sublevels_up == 0) { if ((IsA(node, FuncExpr) && ((FuncExpr *) node)->funcretset) || (IsA(node, OpExpr) && ((OpExpr *) node)->opretset)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("aggregate function calls cannot contain set-returning function calls"), errhint("You might be able to move the set-returning function into a LATERAL FROM item."), parser_errposition(context->pstate, exprLocation(node)))); if (IsA(node, WindowFunc)) ereport(ERROR, (errcode(ERRCODE_GROUPING_ERROR), errmsg("aggregate function calls cannot contain window function calls"), parser_errposition(context->pstate, ((WindowFunc *) node)->location))); } if (IsA(node, Query)) { /* Recurse into subselects */ bool result; context->sublevels_up++; result = query_tree_walker((Query *) node, check_agg_arguments_walker, (void *) context, 0); context->sublevels_up--; return result; } return expression_tree_walker(node, check_agg_arguments_walker, (void *) context); } /* * transformWindowFuncCall - * Finish initial transformation of a window function call * * parse_func.c has recognized the function as a window function, and has set * up all the fields of the WindowFunc except winref. Here we must (1) add * the WindowDef to the pstate (if not a duplicate of one already present) and * set winref to link to it; and (2) mark p_hasWindowFuncs true in the pstate. * Unlike aggregates, only the most closely nested pstate level need be * considered --- there are no "outer window functions" per SQL spec. */ void transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc, WindowDef *windef) { const char *err; bool errkind; /* * A window function call can't contain another one (but aggs are OK). XXX * is this required by spec, or just an unimplemented feature? * * Note: we don't need to check the filter expression here, because the * context checks done below and in transformAggregateCall would have * already rejected any window funcs or aggs within the filter. */ if (pstate->p_hasWindowFuncs && contain_windowfuncs((Node *) wfunc->args)) ereport(ERROR, (errcode(ERRCODE_WINDOWING_ERROR), errmsg("window function calls cannot be nested"), parser_errposition(pstate, locate_windowfunc((Node *) wfunc->args)))); /* * Check to see if the window function is in an invalid place within the * query. * * For brevity we support two schemes for reporting an error here: set * "err" to a custom message, or set "errkind" true if the error context * is sufficiently identified by what ParseExprKindName will return, *and* * what it will return is just a SQL keyword. (Otherwise, use a custom * message to avoid creating translation problems.) */ err = NULL; errkind = false; switch (pstate->p_expr_kind) { case EXPR_KIND_NONE: Assert(false); /* can't happen */ break; case EXPR_KIND_OTHER: /* Accept window func here; caller must throw error if wanted */ break; case EXPR_KIND_JOIN_ON: case EXPR_KIND_JOIN_USING: err = _("window functions are not allowed in JOIN conditions"); break; case EXPR_KIND_FROM_SUBSELECT: /* can't get here, but just in case, throw an error */ errkind = true; break; case EXPR_KIND_FROM_FUNCTION: err = _("window functions are not allowed in functions in FROM"); break; case EXPR_KIND_WHERE: errkind = true; break; case EXPR_KIND_POLICY: err = _("window functions are not allowed in policy expressions"); break; case EXPR_KIND_HAVING: errkind = true; break; case EXPR_KIND_FILTER: errkind = true; break; case EXPR_KIND_WINDOW_PARTITION: case EXPR_KIND_WINDOW_ORDER: case EXPR_KIND_WINDOW_FRAME_RANGE: case EXPR_KIND_WINDOW_FRAME_ROWS: case EXPR_KIND_WINDOW_FRAME_GROUPS: err = _("window functions are not allowed in window definitions"); break; case EXPR_KIND_SELECT_TARGET: /* okay */ break; case EXPR_KIND_INSERT_TARGET: case EXPR_KIND_UPDATE_SOURCE: case EXPR_KIND_UPDATE_TARGET: errkind = true; break; case EXPR_KIND_MERGE_WHEN: err = _("window functions are not allowed in MERGE WHEN conditions"); break; case EXPR_KIND_GROUP_BY: errkind = true; break; case EXPR_KIND_ORDER_BY: /* okay */ break; case EXPR_KIND_DISTINCT_ON: /* okay */ break; case EXPR_KIND_LIMIT: case EXPR_KIND_OFFSET: errkind = true; break; case EXPR_KIND_RETURNING: errkind = true; break; case EXPR_KIND_VALUES: case EXPR_KIND_VALUES_SINGLE: errkind = true; break; case EXPR_KIND_CHECK_CONSTRAINT: case EXPR_KIND_DOMAIN_CHECK: err = _("window functions are not allowed in check constraints"); break; case EXPR_KIND_COLUMN_DEFAULT: case EXPR_KIND_FUNCTION_DEFAULT: err = _("window functions are not allowed in DEFAULT expressions"); break; case EXPR_KIND_INDEX_EXPRESSION: err = _("window functions are not allowed in index expressions"); break; case EXPR_KIND_STATS_EXPRESSION: err = _("window functions are not allowed in statistics expressions"); break; case EXPR_KIND_INDEX_PREDICATE: err = _("window functions are not allowed in index predicates"); break; case EXPR_KIND_ALTER_COL_TRANSFORM: err = _("window functions are not allowed in transform expressions"); break; case EXPR_KIND_EXECUTE_PARAMETER: err = _("window functions are not allowed in EXECUTE parameters"); break; case EXPR_KIND_TRIGGER_WHEN: err = _("window functions are not allowed in trigger WHEN conditions"); break; case EXPR_KIND_PARTITION_BOUND: err = _("window functions are not allowed in partition bound"); break; case EXPR_KIND_PARTITION_EXPRESSION: err = _("window functions are not allowed in partition key expressions"); break; case EXPR_KIND_CALL_ARGUMENT: err = _("window functions are not allowed in CALL arguments"); break; case EXPR_KIND_COPY_WHERE: err = _("window functions are not allowed in COPY FROM WHERE conditions"); break; case EXPR_KIND_GENERATED_COLUMN: err = _("window functions are not allowed in column generation expressions"); break; case EXPR_KIND_CYCLE_MARK: errkind = true; break; /* * There is intentionally no default: case here, so that the * compiler will warn if we add a new ParseExprKind without * extending this switch. If we do see an unrecognized value at * runtime, the behavior will be the same as for EXPR_KIND_OTHER, * which is sane anyway. */ } if (err) ereport(ERROR, (errcode(ERRCODE_WINDOWING_ERROR), errmsg_internal("%s", err), parser_errposition(pstate, wfunc->location))); if (errkind) ereport(ERROR, (errcode(ERRCODE_WINDOWING_ERROR), /* translator: %s is name of a SQL construct, eg GROUP BY */ errmsg("window functions are not allowed in %s", ParseExprKindName(pstate->p_expr_kind)), parser_errposition(pstate, wfunc->location))); /* * If the OVER clause just specifies a window name, find that WINDOW * clause (which had better be present). Otherwise, try to match all the * properties of the OVER clause, and make a new entry in the p_windowdefs * list if no luck. */ if (windef->name) { Index winref = 0; ListCell *lc; Assert(windef->refname == NULL && windef->partitionClause == NIL && windef->orderClause == NIL && windef->frameOptions == FRAMEOPTION_DEFAULTS); foreach(lc, pstate->p_windowdefs) { WindowDef *refwin = (WindowDef *) lfirst(lc); winref++; if (refwin->name && strcmp(refwin->name, windef->name) == 0) { wfunc->winref = winref; break; } } if (lc == NULL) /* didn't find it? */ ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("window \"%s\" does not exist", windef->name), parser_errposition(pstate, windef->location))); } else { Index winref = 0; ListCell *lc; foreach(lc, pstate->p_windowdefs) { WindowDef *refwin = (WindowDef *) lfirst(lc); winref++; if (refwin->refname && windef->refname && strcmp(refwin->refname, windef->refname) == 0) /* matched on refname */ ; else if (!refwin->refname && !windef->refname) /* matched, no refname */ ; else continue; /* * Also see similar de-duplication code in optimize_window_clauses */ if (equal(refwin->partitionClause, windef->partitionClause) && equal(refwin->orderClause, windef->orderClause) && refwin->frameOptions == windef->frameOptions && equal(refwin->startOffset, windef->startOffset) && equal(refwin->endOffset, windef->endOffset)) { /* found a duplicate window specification */ wfunc->winref = winref; break; } } if (lc == NULL) /* didn't find it? */ { pstate->p_windowdefs = lappend(pstate->p_windowdefs, windef); wfunc->winref = list_length(pstate->p_windowdefs); } } pstate->p_hasWindowFuncs = true; } /* * parseCheckAggregates * Check for aggregates where they shouldn't be and improper grouping. * This function should be called after the target list and qualifications * are finalized. * * Misplaced aggregates are now mostly detected in transformAggregateCall, * but it seems more robust to check for aggregates in recursive queries * only after everything is finalized. In any case it's hard to detect * improper grouping on-the-fly, so we have to make another pass over the * query for that. */ void parseCheckAggregates(ParseState *pstate, Query *qry) { List *gset_common = NIL; List *groupClauses = NIL; List *groupClauseCommonVars = NIL; bool have_non_var_grouping; List *func_grouped_rels = NIL; ListCell *l; bool hasJoinRTEs; bool hasSelfRefRTEs; Node *clause; /* This should only be called if we found aggregates or grouping */ Assert(pstate->p_hasAggs || qry->groupClause || qry->havingQual || qry->groupingSets); /* * If we have grouping sets, expand them and find the intersection of all * sets. */ if (qry->groupingSets) { /* * The limit of 4096 is arbitrary and exists simply to avoid resource * issues from pathological constructs. */ List *gsets = expand_grouping_sets(qry->groupingSets, qry->groupDistinct, 4096); if (!gsets) ereport(ERROR, (errcode(ERRCODE_STATEMENT_TOO_COMPLEX), errmsg("too many grouping sets present (maximum 4096)"), parser_errposition(pstate, qry->groupClause ? exprLocation((Node *) qry->groupClause) : exprLocation((Node *) qry->groupingSets)))); /* * The intersection will often be empty, so help things along by * seeding the intersect with the smallest set. */ gset_common = linitial(gsets); if (gset_common) { for_each_from(l, gsets, 1) { gset_common = list_intersection_int(gset_common, lfirst(l)); if (!gset_common) break; } } /* * If there was only one grouping set in the expansion, AND if the * groupClause is non-empty (meaning that the grouping set is not * empty either), then we can ditch the grouping set and pretend we * just had a normal GROUP BY. */ if (list_length(gsets) == 1 && qry->groupClause) qry->groupingSets = NIL; } /* * Scan the range table to see if there are JOIN or self-reference CTE * entries. We'll need this info below. */ hasJoinRTEs = hasSelfRefRTEs = false; foreach(l, pstate->p_rtable) { RangeTblEntry *rte = (RangeTblEntry *) lfirst(l); if (rte->rtekind == RTE_JOIN) hasJoinRTEs = true; else if (rte->rtekind == RTE_CTE && rte->self_reference) hasSelfRefRTEs = true; } /* * Build a list of the acceptable GROUP BY expressions for use by * check_ungrouped_columns(). * * We get the TLE, not just the expr, because GROUPING wants to know the * sortgroupref. */ foreach(l, qry->groupClause) { SortGroupClause *grpcl = (SortGroupClause *) lfirst(l); TargetEntry *expr; expr = get_sortgroupclause_tle(grpcl, qry->targetList); if (expr == NULL) continue; /* probably cannot happen */ groupClauses = lappend(groupClauses, expr); } /* * If there are join alias vars involved, we have to flatten them to the * underlying vars, so that aliased and unaliased vars will be correctly * taken as equal. We can skip the expense of doing this if no rangetable * entries are RTE_JOIN kind. */ if (hasJoinRTEs) groupClauses = (List *) flatten_join_alias_vars(NULL, qry, (Node *) groupClauses); /* * Detect whether any of the grouping expressions aren't simple Vars; if * they're all Vars then we don't have to work so hard in the recursive * scans. (Note we have to flatten aliases before this.) * * Track Vars that are included in all grouping sets separately in * groupClauseCommonVars, since these are the only ones we can use to * check for functional dependencies. */ have_non_var_grouping = false; foreach(l, groupClauses) { TargetEntry *tle = lfirst(l); if (!IsA(tle->expr, Var)) { have_non_var_grouping = true; } else if (!qry->groupingSets || list_member_int(gset_common, tle->ressortgroupref)) { groupClauseCommonVars = lappend(groupClauseCommonVars, tle->expr); } } /* * Check the targetlist and HAVING clause for ungrouped variables. * * Note: because we check resjunk tlist elements as well as regular ones, * this will also find ungrouped variables that came from ORDER BY and * WINDOW clauses. For that matter, it's also going to examine the * grouping expressions themselves --- but they'll all pass the test ... * * We also finalize GROUPING expressions, but for that we need to traverse * the original (unflattened) clause in order to modify nodes. */ clause = (Node *) qry->targetList; finalize_grouping_exprs(clause, pstate, qry, groupClauses, hasJoinRTEs, have_non_var_grouping); if (hasJoinRTEs) clause = flatten_join_alias_vars(NULL, qry, clause); check_ungrouped_columns(clause, pstate, qry, groupClauses, groupClauseCommonVars, have_non_var_grouping, &func_grouped_rels); clause = (Node *) qry->havingQual; finalize_grouping_exprs(clause, pstate, qry, groupClauses, hasJoinRTEs, have_non_var_grouping); if (hasJoinRTEs) clause = flatten_join_alias_vars(NULL, qry, clause); check_ungrouped_columns(clause, pstate, qry, groupClauses, groupClauseCommonVars, have_non_var_grouping, &func_grouped_rels); /* * Per spec, aggregates can't appear in a recursive term. */ if (pstate->p_hasAggs && hasSelfRefRTEs) ereport(ERROR, (errcode(ERRCODE_INVALID_RECURSION), errmsg("aggregate functions are not allowed in a recursive query's recursive term"), parser_errposition(pstate, locate_agg_of_level((Node *) qry, 0)))); } /* * check_ungrouped_columns - * Scan the given expression tree for ungrouped variables (variables * that are not listed in the groupClauses list and are not within * the arguments of aggregate functions). Emit a suitable error message * if any are found. * * NOTE: we assume that the given clause has been transformed suitably for * parser output. This means we can use expression_tree_walker. * * NOTE: we recognize grouping expressions in the main query, but only * grouping Vars in subqueries. For example, this will be rejected, * although it could be allowed: * SELECT * (SELECT x FROM bar where y = (foo.a + foo.b)) * FROM foo * GROUP BY a + b; * The difficulty is the need to account for different sublevels_up. * This appears to require a whole custom version of equal(), which is * way more pain than the feature seems worth. */ static void check_ungrouped_columns(Node *node, ParseState *pstate, Query *qry, List *groupClauses, List *groupClauseCommonVars, bool have_non_var_grouping, List **func_grouped_rels) { check_ungrouped_columns_context context; context.pstate = pstate; context.qry = qry; context.hasJoinRTEs = false; /* assume caller flattened join Vars */ context.groupClauses = groupClauses; context.groupClauseCommonVars = groupClauseCommonVars; context.have_non_var_grouping = have_non_var_grouping; context.func_grouped_rels = func_grouped_rels; context.sublevels_up = 0; context.in_agg_direct_args = false; check_ungrouped_columns_walker(node, &context); } static bool check_ungrouped_columns_walker(Node *node, check_ungrouped_columns_context *context) { ListCell *gl; if (node == NULL) return false; if (IsA(node, Const) || IsA(node, Param)) return false; /* constants are always acceptable */ if (IsA(node, Aggref)) { Aggref *agg = (Aggref *) node; if ((int) agg->agglevelsup == context->sublevels_up) { /* * If we find an aggregate call of the original level, do not * recurse into its normal arguments, ORDER BY arguments, or * filter; ungrouped vars there are not an error. But we should * check direct arguments as though they weren't in an aggregate. * We set a special flag in the context to help produce a useful * error message for ungrouped vars in direct arguments. */ bool result; Assert(!context->in_agg_direct_args); context->in_agg_direct_args = true; result = check_ungrouped_columns_walker((Node *) agg->aggdirectargs, context); context->in_agg_direct_args = false; return result; } /* * We can skip recursing into aggregates of higher levels altogether, * since they could not possibly contain Vars of concern to us (see * transformAggregateCall). We do need to look at aggregates of lower * levels, however. */ if ((int) agg->agglevelsup > context->sublevels_up) return false; } if (IsA(node, GroupingFunc)) { GroupingFunc *grp = (GroupingFunc *) node; /* handled GroupingFunc separately, no need to recheck at this level */ if ((int) grp->agglevelsup >= context->sublevels_up) return false; } /* * If we have any GROUP BY items that are not simple Vars, check to see if * subexpression as a whole matches any GROUP BY item. We need to do this * at every recursion level so that we recognize GROUPed-BY expressions * before reaching variables within them. But this only works at the outer * query level, as noted above. */ if (context->have_non_var_grouping && context->sublevels_up == 0) { foreach(gl, context->groupClauses) { TargetEntry *tle = lfirst(gl); if (equal(node, tle->expr)) return false; /* acceptable, do not descend more */ } } /* * If we have an ungrouped Var of the original query level, we have a * failure. Vars below the original query level are not a problem, and * neither are Vars from above it. (If such Vars are ungrouped as far as * their own query level is concerned, that's someone else's problem...) */ if (IsA(node, Var)) { Var *var = (Var *) node; RangeTblEntry *rte; char *attname; if (var->varlevelsup != context->sublevels_up) return false; /* it's not local to my query, ignore */ /* * Check for a match, if we didn't do it above. */ if (!context->have_non_var_grouping || context->sublevels_up != 0) { foreach(gl, context->groupClauses) { Var *gvar = (Var *) ((TargetEntry *) lfirst(gl))->expr; if (IsA(gvar, Var) && gvar->varno == var->varno && gvar->varattno == var->varattno && gvar->varlevelsup == 0) return false; /* acceptable, we're okay */ } } /* * Check whether the Var is known functionally dependent on the GROUP * BY columns. If so, we can allow the Var to be used, because the * grouping is really a no-op for this table. However, this deduction * depends on one or more constraints of the table, so we have to add * those constraints to the query's constraintDeps list, because it's * not semantically valid anymore if the constraint(s) get dropped. * (Therefore, this check must be the last-ditch effort before raising * error: we don't want to add dependencies unnecessarily.) * * Because this is a pretty expensive check, and will have the same * outcome for all columns of a table, we remember which RTEs we've * already proven functional dependency for in the func_grouped_rels * list. This test also prevents us from adding duplicate entries to * the constraintDeps list. */ if (list_member_int(*context->func_grouped_rels, var->varno)) return false; /* previously proven acceptable */ Assert(var->varno > 0 && (int) var->varno <= list_length(context->pstate->p_rtable)); rte = rt_fetch(var->varno, context->pstate->p_rtable); if (rte->rtekind == RTE_RELATION) { if (check_functional_grouping(rte->relid, var->varno, 0, context->groupClauseCommonVars, &context->qry->constraintDeps)) { *context->func_grouped_rels = lappend_int(*context->func_grouped_rels, var->varno); return false; /* acceptable */ } } /* Found an ungrouped local variable; generate error message */ attname = get_rte_attribute_name(rte, var->varattno); if (context->sublevels_up == 0) ereport(ERROR, (errcode(ERRCODE_GROUPING_ERROR), errmsg("column \"%s.%s\" must appear in the GROUP BY clause or be used in an aggregate function", rte->eref->aliasname, attname), context->in_agg_direct_args ? errdetail("Direct arguments of an ordered-set aggregate must use only grouped columns.") : 0, parser_errposition(context->pstate, var->location))); else ereport(ERROR, (errcode(ERRCODE_GROUPING_ERROR), errmsg("subquery uses ungrouped column \"%s.%s\" from outer query", rte->eref->aliasname, attname), parser_errposition(context->pstate, var->location))); } if (IsA(node, Query)) { /* Recurse into subselects */ bool result; context->sublevels_up++; result = query_tree_walker((Query *) node, check_ungrouped_columns_walker, (void *) context, 0); context->sublevels_up--; return result; } return expression_tree_walker(node, check_ungrouped_columns_walker, (void *) context); } /* * finalize_grouping_exprs - * Scan the given expression tree for GROUPING() and related calls, * and validate and process their arguments. * * This is split out from check_ungrouped_columns above because it needs * to modify the nodes (which it does in-place, not via a mutator) while * check_ungrouped_columns may see only a copy of the original thanks to * flattening of join alias vars. So here, we flatten each individual * GROUPING argument as we see it before comparing it. */ static void finalize_grouping_exprs(Node *node, ParseState *pstate, Query *qry, List *groupClauses, bool hasJoinRTEs, bool have_non_var_grouping) { check_ungrouped_columns_context context; context.pstate = pstate; context.qry = qry; context.hasJoinRTEs = hasJoinRTEs; context.groupClauses = groupClauses; context.groupClauseCommonVars = NIL; context.have_non_var_grouping = have_non_var_grouping; context.func_grouped_rels = NULL; context.sublevels_up = 0; context.in_agg_direct_args = false; finalize_grouping_exprs_walker(node, &context); } static bool finalize_grouping_exprs_walker(Node *node, check_ungrouped_columns_context *context) { ListCell *gl; if (node == NULL) return false; if (IsA(node, Const) || IsA(node, Param)) return false; /* constants are always acceptable */ if (IsA(node, Aggref)) { Aggref *agg = (Aggref *) node; if ((int) agg->agglevelsup == context->sublevels_up) { /* * If we find an aggregate call of the original level, do not * recurse into its normal arguments, ORDER BY arguments, or * filter; GROUPING exprs of this level are not allowed there. But * check direct arguments as though they weren't in an aggregate. */ bool result; Assert(!context->in_agg_direct_args); context->in_agg_direct_args = true; result = finalize_grouping_exprs_walker((Node *) agg->aggdirectargs, context); context->in_agg_direct_args = false; return result; } /* * We can skip recursing into aggregates of higher levels altogether, * since they could not possibly contain exprs of concern to us (see * transformAggregateCall). We do need to look at aggregates of lower * levels, however. */ if ((int) agg->agglevelsup > context->sublevels_up) return false; } if (IsA(node, GroupingFunc)) { GroupingFunc *grp = (GroupingFunc *) node; /* * We only need to check GroupingFunc nodes at the exact level to * which they belong, since they cannot mix levels in arguments. */ if ((int) grp->agglevelsup == context->sublevels_up) { ListCell *lc; List *ref_list = NIL; foreach(lc, grp->args) { Node *expr = lfirst(lc); Index ref = 0; if (context->hasJoinRTEs) expr = flatten_join_alias_vars(NULL, context->qry, expr); /* * Each expression must match a grouping entry at the current * query level. Unlike the general expression case, we don't * allow functional dependencies or outer references. */ if (IsA(expr, Var)) { Var *var = (Var *) expr; if (var->varlevelsup == context->sublevels_up) { foreach(gl, context->groupClauses) { TargetEntry *tle = lfirst(gl); Var *gvar = (Var *) tle->expr; if (IsA(gvar, Var) && gvar->varno == var->varno && gvar->varattno == var->varattno && gvar->varlevelsup == 0) { ref = tle->ressortgroupref; break; } } } } else if (context->have_non_var_grouping && context->sublevels_up == 0) { foreach(gl, context->groupClauses) { TargetEntry *tle = lfirst(gl); if (equal(expr, tle->expr)) { ref = tle->ressortgroupref; break; } } } if (ref == 0) ereport(ERROR, (errcode(ERRCODE_GROUPING_ERROR), errmsg("arguments to GROUPING must be grouping expressions of the associated query level"), parser_errposition(context->pstate, exprLocation(expr)))); ref_list = lappend_int(ref_list, ref); } grp->refs = ref_list; } if ((int) grp->agglevelsup > context->sublevels_up) return false; } if (IsA(node, Query)) { /* Recurse into subselects */ bool result; context->sublevels_up++; result = query_tree_walker((Query *) node, finalize_grouping_exprs_walker, (void *) context, 0); context->sublevels_up--; return result; } return expression_tree_walker(node, finalize_grouping_exprs_walker, (void *) context); } /* * Given a GroupingSet node, expand it and return a list of lists. * * For EMPTY nodes, return a list of one empty list. * * For SIMPLE nodes, return a list of one list, which is the node content. * * For CUBE and ROLLUP nodes, return a list of the expansions. * * For SET nodes, recursively expand contained CUBE and ROLLUP. */ static List * expand_groupingset_node(GroupingSet *gs) { List *result = NIL; switch (gs->kind) { case GROUPING_SET_EMPTY: result = list_make1(NIL); break; case GROUPING_SET_SIMPLE: result = list_make1(gs->content); break; case GROUPING_SET_ROLLUP: { List *rollup_val = gs->content; ListCell *lc; int curgroup_size = list_length(gs->content); while (curgroup_size > 0) { List *current_result = NIL; int i = curgroup_size; foreach(lc, rollup_val) { GroupingSet *gs_current = (GroupingSet *) lfirst(lc); Assert(gs_current->kind == GROUPING_SET_SIMPLE); current_result = list_concat(current_result, gs_current->content); /* If we are done with making the current group, break */ if (--i == 0) break; } result = lappend(result, current_result); --curgroup_size; } result = lappend(result, NIL); } break; case GROUPING_SET_CUBE: { List *cube_list = gs->content; int number_bits = list_length(cube_list); uint32 num_sets; uint32 i; /* parser should cap this much lower */ Assert(number_bits < 31); num_sets = (1U << number_bits); for (i = 0; i < num_sets; i++) { List *current_result = NIL; ListCell *lc; uint32 mask = 1U; foreach(lc, cube_list) { GroupingSet *gs_current = (GroupingSet *) lfirst(lc); Assert(gs_current->kind == GROUPING_SET_SIMPLE); if (mask & i) current_result = list_concat(current_result, gs_current->content); mask <<= 1; } result = lappend(result, current_result); } } break; case GROUPING_SET_SETS: { ListCell *lc; foreach(lc, gs->content) { List *current_result = expand_groupingset_node(lfirst(lc)); result = list_concat(result, current_result); } } break; } return result; } /* list_sort comparator to sort sub-lists by length */ static int cmp_list_len_asc(const ListCell *a, const ListCell *b) { int la = list_length((const List *) lfirst(a)); int lb = list_length((const List *) lfirst(b)); return pg_cmp_s32(la, lb); } /* list_sort comparator to sort sub-lists by length and contents */ static int cmp_list_len_contents_asc(const ListCell *a, const ListCell *b) { int res = cmp_list_len_asc(a, b); if (res == 0) { List *la = (List *) lfirst(a); List *lb = (List *) lfirst(b); ListCell *lca; ListCell *lcb; forboth(lca, la, lcb, lb) { int va = lfirst_int(lca); int vb = lfirst_int(lcb); if (va > vb) return 1; if (va < vb) return -1; } } return res; } /* * Expand a groupingSets clause to a flat list of grouping sets. * The returned list is sorted by length, shortest sets first. * * This is mainly for the planner, but we use it here too to do * some consistency checks. */ List * expand_grouping_sets(List *groupingSets, bool groupDistinct, int limit) { List *expanded_groups = NIL; List *result = NIL; double numsets = 1; ListCell *lc; if (groupingSets == NIL) return NIL; foreach(lc, groupingSets) { List *current_result = NIL; GroupingSet *gs = lfirst(lc); current_result = expand_groupingset_node(gs); Assert(current_result != NIL); numsets *= list_length(current_result); if (limit >= 0 && numsets > limit) return NIL; expanded_groups = lappend(expanded_groups, current_result); } /* * Do cartesian product between sublists of expanded_groups. While at it, * remove any duplicate elements from individual grouping sets (we must * NOT change the number of sets though) */ foreach(lc, (List *) linitial(expanded_groups)) { result = lappend(result, list_union_int(NIL, (List *) lfirst(lc))); } for_each_from(lc, expanded_groups, 1) { List *p = lfirst(lc); List *new_result = NIL; ListCell *lc2; foreach(lc2, result) { List *q = lfirst(lc2); ListCell *lc3; foreach(lc3, p) { new_result = lappend(new_result, list_union_int(q, (List *) lfirst(lc3))); } } result = new_result; } /* Now sort the lists by length and deduplicate if necessary */ if (!groupDistinct || list_length(result) < 2) list_sort(result, cmp_list_len_asc); else { ListCell *cell; List *prev; /* Sort each groupset individually */ foreach(cell, result) list_sort(lfirst(cell), list_int_cmp); /* Now sort the list of groupsets by length and contents */ list_sort(result, cmp_list_len_contents_asc); /* Finally, remove duplicates */ prev = linitial(result); for_each_from(cell, result, 1) { if (equal(lfirst(cell), prev)) result = foreach_delete_current(result, cell); else prev = lfirst(cell); } } return result; } /* * get_aggregate_argtypes * Identify the specific datatypes passed to an aggregate call. * * Given an Aggref, extract the actual datatypes of the input arguments. * The input datatypes are reported in a way that matches up with the * aggregate's declaration, ie, any ORDER BY columns attached to a plain * aggregate are ignored, but we report both direct and aggregated args of * an ordered-set aggregate. * * Datatypes are returned into inputTypes[], which must reference an array * of length FUNC_MAX_ARGS. * * The function result is the number of actual arguments. */ int get_aggregate_argtypes(Aggref *aggref, Oid *inputTypes) { int numArguments = 0; ListCell *lc; Assert(list_length(aggref->aggargtypes) <= FUNC_MAX_ARGS); foreach(lc, aggref->aggargtypes) { inputTypes[numArguments++] = lfirst_oid(lc); } return numArguments; } /* * resolve_aggregate_transtype * Identify the transition state value's datatype for an aggregate call. * * This function resolves a polymorphic aggregate's state datatype. * It must be passed the aggtranstype from the aggregate's catalog entry, * as well as the actual argument types extracted by get_aggregate_argtypes. * (We could fetch pg_aggregate.aggtranstype internally, but all existing * callers already have the value at hand, so we make them pass it.) */ Oid resolve_aggregate_transtype(Oid aggfuncid, Oid aggtranstype, Oid *inputTypes, int numArguments) { /* resolve actual type of transition state, if polymorphic */ if (IsPolymorphicType(aggtranstype)) { /* have to fetch the agg's declared input types... */ Oid *declaredArgTypes; int agg_nargs; (void) get_func_signature(aggfuncid, &declaredArgTypes, &agg_nargs); /* * VARIADIC ANY aggs could have more actual than declared args, but * such extra args can't affect polymorphic type resolution. */ Assert(agg_nargs <= numArguments); aggtranstype = enforce_generic_type_consistency(inputTypes, declaredArgTypes, agg_nargs, aggtranstype, false); pfree(declaredArgTypes); } return aggtranstype; } /* * agg_args_support_sendreceive * Returns true if all non-byval of aggref's arg types have send and * receive functions. */ bool agg_args_support_sendreceive(Aggref *aggref) { ListCell *lc; foreach(lc, aggref->args) { HeapTuple typeTuple; Form_pg_type pt; TargetEntry *tle = (TargetEntry *) lfirst(lc); Oid type = exprType((Node *) tle->expr); typeTuple = SearchSysCache1(TYPEOID, ObjectIdGetDatum(type)); if (!HeapTupleIsValid(typeTuple)) elog(ERROR, "cache lookup failed for type %u", type); pt = (Form_pg_type) GETSTRUCT(typeTuple); if (!pt->typbyval && (!OidIsValid(pt->typsend) || !OidIsValid(pt->typreceive))) { ReleaseSysCache(typeTuple); return false; } ReleaseSysCache(typeTuple); } return true; } /* * Create an expression tree for the transition function of an aggregate. * This is needed so that polymorphic functions can be used within an * aggregate --- without the expression tree, such functions would not know * the datatypes they are supposed to use. (The trees will never actually * be executed, however, so we can skimp a bit on correctness.) * * agg_input_types and agg_state_type identifies the input types of the * aggregate. These should be resolved to actual types (ie, none should * ever be ANYELEMENT etc). * agg_input_collation is the aggregate function's input collation. * * For an ordered-set aggregate, remember that agg_input_types describes * the direct arguments followed by the aggregated arguments. * * transfn_oid and invtransfn_oid identify the funcs to be called; the * latter may be InvalidOid, however if invtransfn_oid is set then * transfn_oid must also be set. * * transfn_oid may also be passed as the aggcombinefn when the *transfnexpr is * to be used for a combine aggregate phase. We expect invtransfn_oid to be * InvalidOid in this case since there is no such thing as an inverse * combinefn. * * Pointers to the constructed trees are returned into *transfnexpr, * *invtransfnexpr. If there is no invtransfn, the respective pointer is set * to NULL. Since use of the invtransfn is optional, NULL may be passed for * invtransfnexpr. */ void build_aggregate_transfn_expr(Oid *agg_input_types, int agg_num_inputs, int agg_num_direct_inputs, bool agg_variadic, Oid agg_state_type, Oid agg_input_collation, Oid transfn_oid, Oid invtransfn_oid, Expr **transfnexpr, Expr **invtransfnexpr) { List *args; FuncExpr *fexpr; int i; /* * Build arg list to use in the transfn FuncExpr node. */ args = list_make1(make_agg_arg(agg_state_type, agg_input_collation)); for (i = agg_num_direct_inputs; i < agg_num_inputs; i++) { args = lappend(args, make_agg_arg(agg_input_types[i], agg_input_collation)); } fexpr = makeFuncExpr(transfn_oid, agg_state_type, args, InvalidOid, agg_input_collation, COERCE_EXPLICIT_CALL); fexpr->funcvariadic = agg_variadic; *transfnexpr = (Expr *) fexpr; /* * Build invtransfn expression if requested, with same args as transfn */ if (invtransfnexpr != NULL) { if (OidIsValid(invtransfn_oid)) { fexpr = makeFuncExpr(invtransfn_oid, agg_state_type, args, InvalidOid, agg_input_collation, COERCE_EXPLICIT_CALL); fexpr->funcvariadic = agg_variadic; *invtransfnexpr = (Expr *) fexpr; } else *invtransfnexpr = NULL; } } /* * Like build_aggregate_transfn_expr, but creates an expression tree for the * serialization function of an aggregate. */ void build_aggregate_serialfn_expr(Oid serialfn_oid, Expr **serialfnexpr) { List *args; FuncExpr *fexpr; /* serialfn always takes INTERNAL and returns BYTEA */ args = list_make1(make_agg_arg(INTERNALOID, InvalidOid)); fexpr = makeFuncExpr(serialfn_oid, BYTEAOID, args, InvalidOid, InvalidOid, COERCE_EXPLICIT_CALL); *serialfnexpr = (Expr *) fexpr; } /* * Like build_aggregate_transfn_expr, but creates an expression tree for the * deserialization function of an aggregate. */ void build_aggregate_deserialfn_expr(Oid deserialfn_oid, Expr **deserialfnexpr) { List *args; FuncExpr *fexpr; /* deserialfn always takes BYTEA, INTERNAL and returns INTERNAL */ args = list_make2(make_agg_arg(BYTEAOID, InvalidOid), make_agg_arg(INTERNALOID, InvalidOid)); fexpr = makeFuncExpr(deserialfn_oid, INTERNALOID, args, InvalidOid, InvalidOid, COERCE_EXPLICIT_CALL); *deserialfnexpr = (Expr *) fexpr; } /* * Like build_aggregate_transfn_expr, but creates an expression tree for the * final function of an aggregate, rather than the transition function. */ void build_aggregate_finalfn_expr(Oid *agg_input_types, int num_finalfn_inputs, Oid agg_state_type, Oid agg_result_type, Oid agg_input_collation, Oid finalfn_oid, Expr **finalfnexpr) { List *args; int i; /* * Build expr tree for final function */ args = list_make1(make_agg_arg(agg_state_type, agg_input_collation)); /* finalfn may take additional args, which match agg's input types */ for (i = 0; i < num_finalfn_inputs - 1; i++) { args = lappend(args, make_agg_arg(agg_input_types[i], agg_input_collation)); } *finalfnexpr = (Expr *) makeFuncExpr(finalfn_oid, agg_result_type, args, InvalidOid, agg_input_collation, COERCE_EXPLICIT_CALL); /* finalfn is currently never treated as variadic */ } /* * Convenience function to build dummy argument expressions for aggregates. * * We really only care that an aggregate support function can discover its * actual argument types at runtime using get_fn_expr_argtype(), so it's okay * to use Param nodes that don't correspond to any real Param. */ static Node * make_agg_arg(Oid argtype, Oid argcollation) { Param *argp = makeNode(Param); argp->paramkind = PARAM_EXEC; argp->paramid = -1; argp->paramtype = argtype; argp->paramtypmod = -1; argp->paramcollid = argcollation; argp->location = -1; return (Node *) argp; }