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Tom Lane
34d26872ed
non-kluge method for controlling the order in which values are fed to an aggregate function. At the same time eliminate the old implementation restriction that DISTINCT was only supported for single-argument aggregates. Possibly release-notable behavioral change: formerly, agg(DISTINCT x) dropped null values of x unconditionally. Now, it does so only if the agg transition function is strict; otherwise nulls are treated as DISTINCT normally would, ie, you get one copy. Andrew Gierth, reviewed by Hitoshi Harada
36 lines
1.1 KiB
C
36 lines
1.1 KiB
C
/*-------------------------------------------------------------------------
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*
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* parse_agg.h
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* handle aggregates and window functions in parser
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*
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* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $PostgreSQL: pgsql/src/include/parser/parse_agg.h,v 1.40 2009/12/15 17:57:47 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef PARSE_AGG_H
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#define PARSE_AGG_H
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#include "parser/parse_node.h"
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extern void transformAggregateCall(ParseState *pstate, Aggref *agg,
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bool agg_distinct);
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extern void transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc,
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WindowDef *windef);
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extern void parseCheckAggregates(ParseState *pstate, Query *qry);
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extern void parseCheckWindowFuncs(ParseState *pstate, Query *qry);
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extern void build_aggregate_fnexprs(Oid *agg_input_types,
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int agg_num_inputs,
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Oid agg_state_type,
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Oid agg_result_type,
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Oid transfn_oid,
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Oid finalfn_oid,
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Expr **transfnexpr,
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Expr **finalfnexpr);
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#endif /* PARSE_AGG_H */
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