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Aggregate functions now support multiple input arguments. I also took

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the opportunity to treat COUNT(*) as a zero-argument aggregate instead
of the old hack that equated it to COUNT(1); this is materially cleaner
(no more weird ANYOID cases) and ought to be at least a tiny bit faster.
Original patch by Sergey Koposov; review, documentation, simple regression
tests, pg_dump and psql support by moi.
This commit is contained in:
Tom Lane
2006-07-27 19:52:07 +00:00
parent c2d1138351
commit 108fe47301
39 changed files with 702 additions and 484 deletions
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53
src/backend/commands/aggregatecmds.c
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@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/commands/aggregatecmds.c,v 1.37 2006/07/14 14:52:18 momjian Exp $
* $PostgreSQL: pgsql/src/backend/commands/aggregatecmds.c,v 1.38 2006/07/27 19:52:04 tgl Exp $
*
* DESCRIPTION
* The "DefineFoo" routines take the parse tree and pick out the
@ -57,7 +57,8 @@ DefineAggregate(List *name, List *args, bool oldstyle, List *parameters)
TypeName *baseType = NULL;
TypeName *transType = NULL;
char *initval = NULL;
Oid baseTypeId;
Oid *aggArgTypes;
int numArgs;
Oid transTypeId;
ListCell *pl;
@ -116,12 +117,13 @@ DefineAggregate(List *name, List *args, bool oldstyle, List *parameters)
errmsg("aggregate sfunc must be specified")));
/*
* look up the aggregate's input datatype.
* look up the aggregate's input datatype(s).
*/
if (oldstyle)
{
/*
* Old style: use basetype parameter. This supports only one input.
* Old style: use basetype parameter. This supports aggregates
* of zero or one input, with input type ANY meaning zero inputs.
*
* Historically we allowed the command to look like basetype = 'ANY'
* so we must do a case-insensitive comparison for the name ANY. Ugh.
@ -132,37 +134,37 @@ DefineAggregate(List *name, List *args, bool oldstyle, List *parameters)
errmsg("aggregate input type must be specified")));
if (pg_strcasecmp(TypeNameToString(baseType), "ANY") == 0)
baseTypeId = ANYOID;
{
numArgs = 0;
aggArgTypes = NULL;
}
else
baseTypeId = typenameTypeId(NULL, baseType);
{
numArgs = 1;
aggArgTypes = (Oid *) palloc(sizeof(Oid));
aggArgTypes[0] = typenameTypeId(NULL, baseType);
}
}
else
{
/*
* New style: args is a list of TypeNames. For the moment, though,
* we allow at most one.
* New style: args is a list of TypeNames (possibly zero of 'em).
*/
ListCell *lc;
int i = 0;
if (baseType != NULL)
ereport(ERROR,
(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
errmsg("basetype is redundant with aggregate input type specification")));
if (args == NIL)
numArgs = list_length(args);
aggArgTypes = (Oid *) palloc(sizeof(Oid) * numArgs);
foreach(lc, args)
{
/* special case for agg(*) */
baseTypeId = ANYOID;
}
else if (list_length(args) != 1)
{
/* temporarily reject > 1 arg */
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("aggregates can have only one input")));
baseTypeId = InvalidOid; /* keep compiler quiet */
}
else
{
baseTypeId = typenameTypeId(NULL, (TypeName *) linitial(args));
TypeName *curTypeName = (TypeName *) lfirst(lc);
aggArgTypes[i++] = typenameTypeId(NULL, curTypeName);
}
}
@ -187,7 +189,8 @@ DefineAggregate(List *name, List *args, bool oldstyle, List *parameters)
*/
AggregateCreate(aggName, /* aggregate name */
aggNamespace, /* namespace */
baseTypeId, /* type of data being aggregated */
aggArgTypes, /* input data type(s) */
numArgs,
transfuncName, /* step function name */
finalfuncName, /* final function name */
sortoperatorName, /* sort operator name */
@ -211,7 +214,7 @@ RemoveAggregate(RemoveFuncStmt *stmt)
/* Look up function and make sure it's an aggregate */
procOid = LookupAggNameTypeNames(aggName, aggArgs, stmt->missing_ok);
if (!OidIsValid(procOid))
{
/* we only get here if stmt->missing_ok is true */