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Aggregates can be polymorphic, using polymorphic implementation functions.

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It also works to create a non-polymorphic aggregate from polymorphic
functions, should you want to do that.  Regression test added, docs still
lacking.  By Joe Conway, with some kibitzing from Tom Lane.
This commit is contained in:
Tom Lane
2003-07-01 19:10:53 +00:00
parent 02b5d8e371
commit e3b1b6c0cd
15 changed files with 1300 additions and 83 deletions
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77
src/backend/executor/nodeAgg.c
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@ -45,7 +45,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/executor/nodeAgg.c,v 1.109 2003/06/25 21:30:28 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/executor/nodeAgg.c,v 1.110 2003/07/01 19:10:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -59,6 +59,7 @@
#include "executor/nodeAgg.h"
#include "miscadmin.h"
#include "optimizer/clauses.h"
#include "parser/parse_agg.h"
#include "parser/parse_coerce.h"
#include "parser/parse_expr.h"
#include "parser/parse_oper.h"
@ -1182,11 +1183,15 @@ ExecInitAgg(Agg *node, EState *estate)
AggrefExprState *aggrefstate = (AggrefExprState *) lfirst(alist);
Aggref *aggref = (Aggref *) aggrefstate->xprstate.expr;
AggStatePerAgg peraggstate;
Oid inputType;
HeapTuple aggTuple;
Form_pg_aggregate aggform;
Oid aggtranstype;
AclResult aclresult;
Oid transfn_oid,
finalfn_oid;
Expr *transfnexpr,
*finalfnexpr;
Datum textInitVal;
int i;
@ -1217,6 +1222,13 @@ ExecInitAgg(Agg *node, EState *estate)
peraggstate->aggrefstate = aggrefstate;
peraggstate->aggref = aggref;
/*
* Get actual datatype of the input. We need this because it may
* be different from the agg's declared input type, when the agg
* accepts ANY (eg, COUNT(*)) or ANYARRAY or ANYELEMENT.
*/
inputType = exprType((Node *) aggref->target);
aggTuple = SearchSysCache(AGGFNOID,
ObjectIdGetDatum(aggref->aggfnoid),
0, 0, 0);
@ -1231,10 +1243,47 @@ ExecInitAgg(Agg *node, EState *estate)
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, get_func_name(aggref->aggfnoid));
peraggstate->transfn_oid = transfn_oid = aggform->aggtransfn;
peraggstate->finalfn_oid = finalfn_oid = aggform->aggfinalfn;
/* resolve actual type of transition state, if polymorphic */
aggtranstype = aggform->aggtranstype;
if (aggtranstype == ANYARRAYOID || aggtranstype == ANYELEMENTOID)
{
/* have to fetch the agg's declared input type... */
Oid agg_arg_types[FUNC_MAX_ARGS];
int agg_nargs;
(void) get_func_signature(aggref->aggfnoid,
agg_arg_types, &agg_nargs);
Assert(agg_nargs == 1);
aggtranstype = resolve_generic_type(aggtranstype,
inputType,
agg_arg_types[0]);
}
/* build expression trees using actual argument & result types */
build_aggregate_fnexprs(inputType,
aggtranstype,
aggref->aggtype,
transfn_oid,
finalfn_oid,
&transfnexpr,
&finalfnexpr);
fmgr_info(transfn_oid, &peraggstate->transfn);
peraggstate->transfn.fn_expr = (Node *) transfnexpr;
if (OidIsValid(finalfn_oid))
{
fmgr_info(finalfn_oid, &peraggstate->finalfn);
peraggstate->finalfn.fn_expr = (Node *) finalfnexpr;
}
get_typlenbyval(aggref->aggtype,
&peraggstate->resulttypeLen,
&peraggstate->resulttypeByVal);
get_typlenbyval(aggform->aggtranstype,
get_typlenbyval(aggtranstype,
&peraggstate->transtypeLen,
&peraggstate->transtypeByVal);
@ -1250,14 +1299,7 @@ ExecInitAgg(Agg *node, EState *estate)
peraggstate->initValue = (Datum) 0;
else
peraggstate->initValue = GetAggInitVal(textInitVal,
aggform->aggtranstype);
peraggstate->transfn_oid = transfn_oid = aggform->aggtransfn;
peraggstate->finalfn_oid = finalfn_oid = aggform->aggfinalfn;
fmgr_info(transfn_oid, &peraggstate->transfn);
if (OidIsValid(finalfn_oid))
fmgr_info(finalfn_oid, &peraggstate->finalfn);
aggtranstype);
/*
* If the transfn is strict and the initval is NULL, make sure
@ -1268,26 +1310,13 @@ ExecInitAgg(Agg *node, EState *estate)
*/
if (peraggstate->transfn.fn_strict && peraggstate->initValueIsNull)
{
/*
* Note: use the type from the input expression here, not from
* pg_proc.proargtypes, because the latter might be 0.
* (Consider COUNT(*).)
*/
Oid inputType = exprType((Node *) aggref->target);
if (!IsBinaryCoercible(inputType, aggform->aggtranstype))
if (!IsBinaryCoercible(inputType, aggtranstype))
elog(ERROR, "Aggregate %u needs to have compatible input type and transition type",
aggref->aggfnoid);
}
if (aggref->aggdistinct)
{
/*
* Note: use the type from the input expression here, not from
* pg_proc.proargtypes, because the latter might be a pseudotype.
* (Consider COUNT(*).)
*/
Oid inputType = exprType((Node *) aggref->target);
Oid eq_function;
/* We don't implement DISTINCT aggs in the HASHED case */