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Restructure representation of aggregate functions so that they have pg_proc

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entries, per pghackers discussion.  This fixes aggregates to live in
namespaces, and also simplifies/speeds up lookup in parse_func.c.
Also, add a 'proimplicit' flag to pg_proc that controls whether a type
coercion function may be invoked implicitly, or only explicitly.  The
current settings of these flags are more permissive than I would like,
but we will need to debate and refine the behavior; for now, I avoided
breaking regression tests as much as I could.
This commit is contained in:
Tom Lane
2002-04-11 20:00:18 +00:00
parent 3f6299df6c
commit 902a6a0a4b
63 changed files with 2530 additions and 2440 deletions
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97
src/backend/executor/nodeAgg.c
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@ -46,7 +46,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/executor/nodeAgg.c,v 1.80 2002/03/20 19:43:54 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/executor/nodeAgg.c,v 1.81 2002/04/11 19:59:58 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -63,11 +63,13 @@
#include "parser/parse_expr.h"
#include "parser/parse_oper.h"
#include "parser/parse_type.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/syscache.h"
#include "utils/tuplesort.h"
#include "utils/datum.h"
/*
* AggStatePerAggData - per-aggregate working state for the Agg scan
*/
@ -160,6 +162,7 @@ static void process_sorted_aggregate(AggState *aggstate,
AggStatePerAgg peraggstate);
static void finalize_aggregate(AggStatePerAgg peraggstate,
Datum *resultVal, bool *resultIsNull);
static Datum GetAggInitVal(Datum textInitVal, Oid transtype);
/*
@ -244,7 +247,7 @@ advance_transition_function(AggStatePerAgg peraggstate,
* transValue has not been initialized. This is the first
* non-NULL input value. We use it as the initial value for
* transValue. (We already checked that the agg's input type
* is binary- compatible with its transtype, so straight copy
* is binary-compatible with its transtype, so straight copy
* here is OK.)
*
* We had better copy the datum if it is pass-by-ref, since the
@ -838,11 +841,11 @@ ExecInitAgg(Agg *node, EState *estate, Plan *parent)
{
Aggref *aggref = (Aggref *) lfirst(alist);
AggStatePerAgg peraggstate = &peragg[++aggno];
char *aggname = aggref->aggname;
HeapTuple aggTuple;
Form_pg_aggregate aggform;
Oid transfn_oid,
finalfn_oid;
Datum textInitVal;
/* Mark Aggref node with its associated index in the result array */
aggref->aggno = aggno;
@ -850,28 +853,34 @@ ExecInitAgg(Agg *node, EState *estate, Plan *parent)
/* Fill in the peraggstate data */
peraggstate->aggref = aggref;
aggTuple = SearchSysCache(AGGNAME,
PointerGetDatum(aggname),
ObjectIdGetDatum(aggref->basetype),
0, 0);
aggTuple = SearchSysCache(AGGFNOID,
ObjectIdGetDatum(aggref->aggfnoid),
0, 0, 0);
if (!HeapTupleIsValid(aggTuple))
elog(ERROR, "ExecAgg: cache lookup failed for aggregate %s(%s)",
aggname,
aggref->basetype ?
typeidTypeName(aggref->basetype) : (char *) "");
elog(ERROR, "ExecAgg: cache lookup failed for aggregate %u",
aggref->aggfnoid);
aggform = (Form_pg_aggregate) GETSTRUCT(aggTuple);
get_typlenbyval(aggform->aggfinaltype,
get_typlenbyval(aggref->aggtype,
&peraggstate->resulttypeLen,
&peraggstate->resulttypeByVal);
get_typlenbyval(aggform->aggtranstype,
&peraggstate->transtypeLen,
&peraggstate->transtypeByVal);
peraggstate->initValue =
AggNameGetInitVal(aggname,
aggform->aggbasetype,
&peraggstate->initValueIsNull);
/*
* initval is potentially null, so don't try to access it as a struct
* field. Must do it the hard way with SysCacheGetAttr.
*/
textInitVal = SysCacheGetAttr(AGGFNOID, aggTuple,
Anum_pg_aggregate_agginitval,
&peraggstate->initValueIsNull);
if (peraggstate->initValueIsNull)
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;
@ -891,21 +900,21 @@ ExecInitAgg(Agg *node, EState *estate, Plan *parent)
{
/*
* Note: use the type from the input expression here, not
* aggform->aggbasetype, because the latter might be 0.
* from pg_proc.proargtypes, because the latter might be 0.
* (Consider COUNT(*).)
*/
Oid inputType = exprType(aggref->target);
if (!IsBinaryCompatible(inputType, aggform->aggtranstype))
elog(ERROR, "Aggregate %s needs to have compatible input type and transition type",
aggname);
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
* aggform->aggbasetype, because the latter might be 0.
* from pg_proc.proargtypes, because the latter might be 0.
* (Consider COUNT(*).)
*/
Oid inputType = exprType(aggref->target);
@ -932,6 +941,36 @@ ExecInitAgg(Agg *node, EState *estate, Plan *parent)
return TRUE;
}
static Datum
GetAggInitVal(Datum textInitVal, Oid transtype)
{
char *strInitVal;
HeapTuple tup;
Oid typinput,
typelem;
Datum initVal;
strInitVal = DatumGetCString(DirectFunctionCall1(textout, textInitVal));
tup = SearchSysCache(TYPEOID,
ObjectIdGetDatum(transtype),
0, 0, 0);
if (!HeapTupleIsValid(tup))
elog(ERROR, "GetAggInitVal: cache lookup failed on aggregate transition function return type %u", transtype);
typinput = ((Form_pg_type) GETSTRUCT(tup))->typinput;
typelem = ((Form_pg_type) GETSTRUCT(tup))->typelem;
ReleaseSysCache(tup);
initVal = OidFunctionCall3(typinput,
CStringGetDatum(strInitVal),
ObjectIdGetDatum(typelem),
Int32GetDatum(-1));
pfree(strInitVal);
return initVal;
}
int
ExecCountSlotsAgg(Agg *node)
{
@ -985,3 +1024,21 @@ ExecReScanAgg(Agg *node, ExprContext *exprCtxt, Plan *parent)
if (((Plan *) node)->lefttree->chgParam == NULL)
ExecReScan(((Plan *) node)->lefttree, exprCtxt, (Plan *) node);
}
/*
* aggregate_dummy - dummy execution routine for aggregate functions
*
* This function is listed as the implementation (prosrc field) of pg_proc
* entries for aggregate functions. Its only purpose is to throw an error
* if someone mistakenly executes such a function in the normal way.
*
* Perhaps someday we could assign real meaning to the prosrc field of
* an aggregate?
*/
Datum
aggregate_dummy(PG_FUNCTION_ARGS)
{
elog(ERROR, "Aggregate function %u called as normal function",
fcinfo->flinfo->fn_oid);
return (Datum) 0; /* keep compiler quiet */
}