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70c9763d48
change saves a great deal of space in pg_proc and its primary index, and it eliminates the former requirement that INDEX_MAX_KEYS and FUNC_MAX_ARGS have the same value. INDEX_MAX_KEYS is still embedded in the on-disk representation (because it affects index tuple header size), but FUNC_MAX_ARGS is not. I believe it would now be possible to increase FUNC_MAX_ARGS at little cost, but haven't experimented yet. There are still a lot of vestigial references to FUNC_MAX_ARGS, which I will clean up in a separate pass. However, getting rid of it altogether would require changing the FunctionCallInfoData struct, and I'm not sure I want to buy into that.
1550 lines
45 KiB
C
1550 lines
45 KiB
C
/*-------------------------------------------------------------------------
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*
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* nodeAgg.c
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* Routines to handle aggregate nodes.
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*
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* ExecAgg evaluates each aggregate in the following steps:
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*
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* transvalue = initcond
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* foreach input_value do
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* transvalue = transfunc(transvalue, input_value)
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* result = finalfunc(transvalue)
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*
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* If a finalfunc is not supplied then the result is just the ending
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* value of transvalue.
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*
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* If transfunc is marked "strict" in pg_proc and initcond is NULL,
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* then the first non-NULL input_value is assigned directly to transvalue,
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* and transfunc isn't applied until the second non-NULL input_value.
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* The agg's input type and transtype must be the same in this case!
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*
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* If transfunc is marked "strict" then NULL input_values are skipped,
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* keeping the previous transvalue. If transfunc is not strict then it
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* is called for every input tuple and must deal with NULL initcond
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* or NULL input_value for itself.
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*
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* If finalfunc is marked "strict" then it is not called when the
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* ending transvalue is NULL, instead a NULL result is created
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* automatically (this is just the usual handling of strict functions,
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* of course). A non-strict finalfunc can make its own choice of
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* what to return for a NULL ending transvalue.
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*
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* We compute aggregate input expressions and run the transition functions
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* in a temporary econtext (aggstate->tmpcontext). This is reset at
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* least once per input tuple, so when the transvalue datatype is
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* pass-by-reference, we have to be careful to copy it into a longer-lived
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* memory context, and free the prior value to avoid memory leakage.
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* We store transvalues in the memory context aggstate->aggcontext,
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* which is also used for the hashtable structures in AGG_HASHED mode.
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* The node's regular econtext (aggstate->csstate.cstate.cs_ExprContext)
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* is used to run finalize functions and compute the output tuple;
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* this context can be reset once per output tuple.
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*
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* Beginning in PostgreSQL 8.1, the executor's AggState node is passed as
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* the fmgr "context" value in all transfunc and finalfunc calls. It is
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* not really intended that the transition functions will look into the
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* AggState node, but they can use code like
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* if (fcinfo->context && IsA(fcinfo->context, AggState))
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* to verify that they are being called by nodeAgg.c and not as ordinary
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* SQL functions. The main reason a transition function might want to know
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* that is that it can avoid palloc'ing a fixed-size pass-by-ref transition
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* value on every call: it can instead just scribble on and return its left
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* input. Ordinarily it is completely forbidden for functions to modify
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* pass-by-ref inputs, but in the aggregate case we know the left input is
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* either the initial transition value or a previous function result, and
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* in either case its value need not be preserved. See int8inc() for an
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* example. Notice that advance_transition_function() is coded to avoid a
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* data copy step when the previous transition value pointer is returned.
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*
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*
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* Portions Copyright (c) 1996-2005, 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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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/backend/executor/nodeAgg.c,v 1.132 2005/03/29 00:16:59 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "access/heapam.h"
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#include "catalog/pg_aggregate.h"
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#include "catalog/pg_operator.h"
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#include "catalog/pg_proc.h"
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#include "executor/executor.h"
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#include "executor/nodeAgg.h"
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#include "miscadmin.h"
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#include "optimizer/clauses.h"
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#include "parser/parse_agg.h"
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#include "parser/parse_coerce.h"
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#include "parser/parse_expr.h"
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#include "parser/parse_oper.h"
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#include "utils/acl.h"
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#include "utils/builtins.h"
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#include "utils/lsyscache.h"
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#include "utils/syscache.h"
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#include "utils/tuplesort.h"
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#include "utils/datum.h"
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/*
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* AggStatePerAggData - per-aggregate working state for the Agg scan
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*/
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typedef struct AggStatePerAggData
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{
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/*
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* These values are set up during ExecInitAgg() and do not change
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* thereafter:
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*/
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/* Links to Aggref expr and state nodes this working state is for */
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AggrefExprState *aggrefstate;
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Aggref *aggref;
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/* Oids of transfer functions */
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Oid transfn_oid;
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Oid finalfn_oid; /* may be InvalidOid */
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/*
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* fmgr lookup data for transfer functions --- only valid when
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* corresponding oid is not InvalidOid. Note in particular that
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* fn_strict flags are kept here.
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*/
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FmgrInfo transfn;
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FmgrInfo finalfn;
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/*
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* Type of input data and Oid of sort operator to use for it; only
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* set/used when aggregate has DISTINCT flag. (These are not used
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* directly by nodeAgg, but must be passed to the Tuplesort object.)
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*/
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Oid inputType;
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Oid sortOperator;
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/*
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* fmgr lookup data for input type's equality operator --- only
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* set/used when aggregate has DISTINCT flag.
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*/
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FmgrInfo equalfn;
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/*
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* initial value from pg_aggregate entry
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*/
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Datum initValue;
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bool initValueIsNull;
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/*
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* We need the len and byval info for the agg's input, result, and
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* transition data types in order to know how to copy/delete values.
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*/
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int16 inputtypeLen,
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resulttypeLen,
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transtypeLen;
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bool inputtypeByVal,
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resulttypeByVal,
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transtypeByVal;
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/*
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* These values are working state that is initialized at the start of
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* an input tuple group and updated for each input tuple.
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*
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* For a simple (non DISTINCT) aggregate, we just feed the input values
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* straight to the transition function. If it's DISTINCT, we pass the
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* input values into a Tuplesort object; then at completion of the
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* input tuple group, we scan the sorted values, eliminate duplicates,
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* and run the transition function on the rest.
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*/
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Tuplesortstate *sortstate; /* sort object, if a DISTINCT agg */
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} AggStatePerAggData;
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/*
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* AggStatePerGroupData - per-aggregate-per-group working state
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*
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* These values are working state that is initialized at the start of
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* an input tuple group and updated for each input tuple.
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*
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* In AGG_PLAIN and AGG_SORTED modes, we have a single array of these
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* structs (pointed to by aggstate->pergroup); we re-use the array for
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* each input group, if it's AGG_SORTED mode. In AGG_HASHED mode, the
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* hash table contains an array of these structs for each tuple group.
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*
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* Logically, the sortstate field belongs in this struct, but we do not
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* keep it here for space reasons: we don't support DISTINCT aggregates
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* in AGG_HASHED mode, so there's no reason to use up a pointer field
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* in every entry of the hashtable.
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*/
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typedef struct AggStatePerGroupData
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{
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Datum transValue; /* current transition value */
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bool transValueIsNull;
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bool noTransValue; /* true if transValue not set yet */
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/*
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* Note: noTransValue initially has the same value as
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* transValueIsNull, and if true both are cleared to false at the same
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* time. They are not the same though: if transfn later returns a
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* NULL, we want to keep that NULL and not auto-replace it with a
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* later input value. Only the first non-NULL input will be
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* auto-substituted.
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*/
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} AggStatePerGroupData;
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/*
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* To implement hashed aggregation, we need a hashtable that stores a
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* representative tuple and an array of AggStatePerGroup structs for each
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* distinct set of GROUP BY column values. We compute the hash key from
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* the GROUP BY columns.
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*/
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typedef struct AggHashEntryData *AggHashEntry;
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typedef struct AggHashEntryData
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{
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TupleHashEntryData shared; /* common header for hash table entries */
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/* per-aggregate transition status array - must be last! */
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AggStatePerGroupData pergroup[1]; /* VARIABLE LENGTH ARRAY */
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} AggHashEntryData; /* VARIABLE LENGTH STRUCT */
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static void initialize_aggregates(AggState *aggstate,
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AggStatePerAgg peragg,
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AggStatePerGroup pergroup);
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static void advance_transition_function(AggState *aggstate,
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AggStatePerAgg peraggstate,
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AggStatePerGroup pergroupstate,
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Datum newVal, bool isNull);
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static void advance_aggregates(AggState *aggstate, AggStatePerGroup pergroup);
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static void process_sorted_aggregate(AggState *aggstate,
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AggStatePerAgg peraggstate,
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AggStatePerGroup pergroupstate);
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static void finalize_aggregate(AggState *aggstate,
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AggStatePerAgg peraggstate,
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AggStatePerGroup pergroupstate,
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Datum *resultVal, bool *resultIsNull);
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static void build_hash_table(AggState *aggstate);
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static AggHashEntry lookup_hash_entry(AggState *aggstate,
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TupleTableSlot *slot);
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static TupleTableSlot *agg_retrieve_direct(AggState *aggstate);
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static void agg_fill_hash_table(AggState *aggstate);
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static TupleTableSlot *agg_retrieve_hash_table(AggState *aggstate);
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static Datum GetAggInitVal(Datum textInitVal, Oid transtype);
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/*
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* Initialize all aggregates for a new group of input values.
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*
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* When called, CurrentMemoryContext should be the per-query context.
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*/
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static void
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initialize_aggregates(AggState *aggstate,
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AggStatePerAgg peragg,
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AggStatePerGroup pergroup)
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{
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int aggno;
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for (aggno = 0; aggno < aggstate->numaggs; aggno++)
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{
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AggStatePerAgg peraggstate = &peragg[aggno];
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AggStatePerGroup pergroupstate = &pergroup[aggno];
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Aggref *aggref = peraggstate->aggref;
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/*
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* Start a fresh sort operation for each DISTINCT aggregate.
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*/
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if (aggref->aggdistinct)
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{
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/*
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* In case of rescan, maybe there could be an uncompleted sort
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* operation? Clean it up if so.
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*/
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if (peraggstate->sortstate)
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tuplesort_end(peraggstate->sortstate);
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peraggstate->sortstate =
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tuplesort_begin_datum(peraggstate->inputType,
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peraggstate->sortOperator,
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work_mem, false);
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}
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/*
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* If we are reinitializing after a group boundary, we have to
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* free any prior transValue to avoid memory leakage. We must
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* check not only the isnull flag but whether the pointer is NULL;
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* since pergroupstate is initialized with palloc0, the initial
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* condition has isnull = 0 and null pointer.
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*/
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if (!peraggstate->transtypeByVal &&
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!pergroupstate->transValueIsNull &&
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DatumGetPointer(pergroupstate->transValue) != NULL)
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pfree(DatumGetPointer(pergroupstate->transValue));
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/*
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* (Re)set transValue to the initial value.
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*
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* Note that when the initial value is pass-by-ref, we must copy it
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* (into the aggcontext) since we will pfree the transValue later.
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*/
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if (peraggstate->initValueIsNull)
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pergroupstate->transValue = peraggstate->initValue;
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else
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{
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MemoryContext oldContext;
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oldContext = MemoryContextSwitchTo(aggstate->aggcontext);
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pergroupstate->transValue = datumCopy(peraggstate->initValue,
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peraggstate->transtypeByVal,
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peraggstate->transtypeLen);
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MemoryContextSwitchTo(oldContext);
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}
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pergroupstate->transValueIsNull = peraggstate->initValueIsNull;
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/*
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* If the initial value for the transition state doesn't exist in
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* the pg_aggregate table then we will let the first non-NULL
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* value returned from the outer procNode become the initial
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* value. (This is useful for aggregates like max() and min().)
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* The noTransValue flag signals that we still need to do this.
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*/
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pergroupstate->noTransValue = peraggstate->initValueIsNull;
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}
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}
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|
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/*
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* Given a new input value, advance the transition function of an aggregate.
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*
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* It doesn't matter which memory context this is called in.
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*/
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static void
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advance_transition_function(AggState *aggstate,
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AggStatePerAgg peraggstate,
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AggStatePerGroup pergroupstate,
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Datum newVal, bool isNull)
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{
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FunctionCallInfoData fcinfo;
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MemoryContext oldContext;
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if (peraggstate->transfn.fn_strict)
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{
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/*
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* For a strict transfn, nothing happens at a NULL input tuple; we
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* just keep the prior transValue.
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*/
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if (isNull)
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return;
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if (pergroupstate->noTransValue)
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{
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/*
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* transValue has not been initialized. This is the first
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* non-NULL input value. We use it as the initial value for
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* transValue. (We already checked that the agg's input type
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* is binary-compatible with its transtype, so straight copy
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* here is OK.)
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*
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* We must copy the datum into aggcontext if it is pass-by-ref.
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* We do not need to pfree the old transValue, since it's
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* NULL.
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*/
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oldContext = MemoryContextSwitchTo(aggstate->aggcontext);
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pergroupstate->transValue = datumCopy(newVal,
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peraggstate->transtypeByVal,
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peraggstate->transtypeLen);
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pergroupstate->transValueIsNull = false;
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pergroupstate->noTransValue = false;
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MemoryContextSwitchTo(oldContext);
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return;
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}
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if (pergroupstate->transValueIsNull)
|
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{
|
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/*
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* Don't call a strict function with NULL inputs. Note it is
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* possible to get here despite the above tests, if the
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* transfn is strict *and* returned a NULL on a prior cycle.
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* If that happens we will propagate the NULL all the way to
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* the end.
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*/
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return;
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}
|
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}
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|
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/* We run the transition functions in per-input-tuple memory context */
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oldContext = MemoryContextSwitchTo(aggstate->tmpcontext->ecxt_per_tuple_memory);
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|
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/*
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* OK to call the transition function
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*/
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InitFunctionCallInfoData(fcinfo, &(peraggstate->transfn), 2,
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(void *) aggstate, NULL);
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fcinfo.arg[0] = pergroupstate->transValue;
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fcinfo.argnull[0] = pergroupstate->transValueIsNull;
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fcinfo.arg[1] = newVal;
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fcinfo.argnull[1] = isNull;
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|
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newVal = FunctionCallInvoke(&fcinfo);
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|
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/*
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* If pass-by-ref datatype, must copy the new value into aggcontext
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* and pfree the prior transValue. But if transfn returned a pointer
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* to its first input, we don't need to do anything.
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*/
|
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if (!peraggstate->transtypeByVal &&
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DatumGetPointer(newVal) != DatumGetPointer(pergroupstate->transValue))
|
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{
|
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if (!fcinfo.isnull)
|
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{
|
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MemoryContextSwitchTo(aggstate->aggcontext);
|
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newVal = datumCopy(newVal,
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peraggstate->transtypeByVal,
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peraggstate->transtypeLen);
|
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}
|
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if (!pergroupstate->transValueIsNull)
|
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pfree(DatumGetPointer(pergroupstate->transValue));
|
|
}
|
|
|
|
pergroupstate->transValue = newVal;
|
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pergroupstate->transValueIsNull = fcinfo.isnull;
|
|
|
|
MemoryContextSwitchTo(oldContext);
|
|
}
|
|
|
|
/*
|
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* Advance all the aggregates for one input tuple. The input tuple
|
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* has been stored in tmpcontext->ecxt_scantuple, so that it is accessible
|
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* to ExecEvalExpr. pergroup is the array of per-group structs to use
|
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* (this might be in a hashtable entry).
|
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*
|
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* When called, CurrentMemoryContext should be the per-query context.
|
|
*/
|
|
static void
|
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advance_aggregates(AggState *aggstate, AggStatePerGroup pergroup)
|
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{
|
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ExprContext *econtext = aggstate->tmpcontext;
|
|
int aggno;
|
|
|
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for (aggno = 0; aggno < aggstate->numaggs; aggno++)
|
|
{
|
|
AggStatePerAgg peraggstate = &aggstate->peragg[aggno];
|
|
AggStatePerGroup pergroupstate = &pergroup[aggno];
|
|
AggrefExprState *aggrefstate = peraggstate->aggrefstate;
|
|
Aggref *aggref = peraggstate->aggref;
|
|
Datum newVal;
|
|
bool isNull;
|
|
|
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newVal = ExecEvalExprSwitchContext(aggrefstate->target, econtext,
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&isNull, NULL);
|
|
|
|
if (aggref->aggdistinct)
|
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{
|
|
/* in DISTINCT mode, we may ignore nulls */
|
|
if (isNull)
|
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continue;
|
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tuplesort_putdatum(peraggstate->sortstate, newVal, isNull);
|
|
}
|
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else
|
|
{
|
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advance_transition_function(aggstate, peraggstate, pergroupstate,
|
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newVal, isNull);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Run the transition function for a DISTINCT aggregate. This is called
|
|
* after we have completed entering all the input values into the sort
|
|
* object. We complete the sort, read out the values in sorted order,
|
|
* and run the transition function on each non-duplicate value.
|
|
*
|
|
* When called, CurrentMemoryContext should be the per-query context.
|
|
*/
|
|
static void
|
|
process_sorted_aggregate(AggState *aggstate,
|
|
AggStatePerAgg peraggstate,
|
|
AggStatePerGroup pergroupstate)
|
|
{
|
|
Datum oldVal = (Datum) 0;
|
|
bool haveOldVal = false;
|
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MemoryContext workcontext = aggstate->tmpcontext->ecxt_per_tuple_memory;
|
|
MemoryContext oldContext;
|
|
Datum newVal;
|
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bool isNull;
|
|
|
|
tuplesort_performsort(peraggstate->sortstate);
|
|
|
|
/*
|
|
* Note: if input type is pass-by-ref, the datums returned by the sort
|
|
* are freshly palloc'd in the per-query context, so we must be
|
|
* careful to pfree them when they are no longer needed.
|
|
*/
|
|
|
|
while (tuplesort_getdatum(peraggstate->sortstate, true,
|
|
&newVal, &isNull))
|
|
{
|
|
/*
|
|
* DISTINCT always suppresses nulls, per SQL spec, regardless of
|
|
* the transition function's strictness.
|
|
*/
|
|
if (isNull)
|
|
continue;
|
|
|
|
/*
|
|
* Clear and select the working context for evaluation of the
|
|
* equality function and transition function.
|
|
*/
|
|
MemoryContextReset(workcontext);
|
|
oldContext = MemoryContextSwitchTo(workcontext);
|
|
|
|
if (haveOldVal &&
|
|
DatumGetBool(FunctionCall2(&peraggstate->equalfn,
|
|
oldVal, newVal)))
|
|
{
|
|
/* equal to prior, so forget this one */
|
|
if (!peraggstate->inputtypeByVal)
|
|
pfree(DatumGetPointer(newVal));
|
|
}
|
|
else
|
|
{
|
|
advance_transition_function(aggstate, peraggstate, pergroupstate,
|
|
newVal, false);
|
|
/* forget the old value, if any */
|
|
if (haveOldVal && !peraggstate->inputtypeByVal)
|
|
pfree(DatumGetPointer(oldVal));
|
|
/* and remember the new one for subsequent equality checks */
|
|
oldVal = newVal;
|
|
haveOldVal = true;
|
|
}
|
|
|
|
MemoryContextSwitchTo(oldContext);
|
|
}
|
|
|
|
if (haveOldVal && !peraggstate->inputtypeByVal)
|
|
pfree(DatumGetPointer(oldVal));
|
|
|
|
tuplesort_end(peraggstate->sortstate);
|
|
peraggstate->sortstate = NULL;
|
|
}
|
|
|
|
/*
|
|
* Compute the final value of one aggregate.
|
|
*
|
|
* The finalfunction will be run, and the result delivered, in the
|
|
* output-tuple context; caller's CurrentMemoryContext does not matter.
|
|
*/
|
|
static void
|
|
finalize_aggregate(AggState *aggstate,
|
|
AggStatePerAgg peraggstate,
|
|
AggStatePerGroup pergroupstate,
|
|
Datum *resultVal, bool *resultIsNull)
|
|
{
|
|
MemoryContext oldContext;
|
|
|
|
oldContext = MemoryContextSwitchTo(aggstate->ss.ps.ps_ExprContext->ecxt_per_tuple_memory);
|
|
|
|
/*
|
|
* Apply the agg's finalfn if one is provided, else return transValue.
|
|
*/
|
|
if (OidIsValid(peraggstate->finalfn_oid))
|
|
{
|
|
FunctionCallInfoData fcinfo;
|
|
|
|
InitFunctionCallInfoData(fcinfo, &(peraggstate->finalfn), 1,
|
|
(void *) aggstate, NULL);
|
|
fcinfo.arg[0] = pergroupstate->transValue;
|
|
fcinfo.argnull[0] = pergroupstate->transValueIsNull;
|
|
if (fcinfo.flinfo->fn_strict && pergroupstate->transValueIsNull)
|
|
{
|
|
/* don't call a strict function with NULL inputs */
|
|
*resultVal = (Datum) 0;
|
|
*resultIsNull = true;
|
|
}
|
|
else
|
|
{
|
|
*resultVal = FunctionCallInvoke(&fcinfo);
|
|
*resultIsNull = fcinfo.isnull;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
*resultVal = pergroupstate->transValue;
|
|
*resultIsNull = pergroupstate->transValueIsNull;
|
|
}
|
|
|
|
/*
|
|
* If result is pass-by-ref, make sure it is in the right context.
|
|
*/
|
|
if (!peraggstate->resulttypeByVal && !*resultIsNull &&
|
|
!MemoryContextContains(CurrentMemoryContext,
|
|
DatumGetPointer(*resultVal)))
|
|
*resultVal = datumCopy(*resultVal,
|
|
peraggstate->resulttypeByVal,
|
|
peraggstate->resulttypeLen);
|
|
|
|
MemoryContextSwitchTo(oldContext);
|
|
}
|
|
|
|
/*
|
|
* Initialize the hash table to empty.
|
|
*
|
|
* The hash table always lives in the aggcontext memory context.
|
|
*/
|
|
static void
|
|
build_hash_table(AggState *aggstate)
|
|
{
|
|
Agg *node = (Agg *) aggstate->ss.ps.plan;
|
|
MemoryContext tmpmem = aggstate->tmpcontext->ecxt_per_tuple_memory;
|
|
Size entrysize;
|
|
|
|
Assert(node->aggstrategy == AGG_HASHED);
|
|
Assert(node->numGroups > 0);
|
|
|
|
entrysize = sizeof(AggHashEntryData) +
|
|
(aggstate->numaggs - 1) *sizeof(AggStatePerGroupData);
|
|
|
|
aggstate->hashtable = BuildTupleHashTable(node->numCols,
|
|
node->grpColIdx,
|
|
aggstate->eqfunctions,
|
|
aggstate->hashfunctions,
|
|
node->numGroups,
|
|
entrysize,
|
|
aggstate->aggcontext,
|
|
tmpmem);
|
|
}
|
|
|
|
/*
|
|
* Estimate per-hash-table-entry overhead for the planner.
|
|
*
|
|
* Note that the estimate does not include space for pass-by-reference
|
|
* transition data values.
|
|
*/
|
|
Size
|
|
hash_agg_entry_size(int numAggs)
|
|
{
|
|
Size entrysize;
|
|
|
|
/* This must match build_hash_table */
|
|
entrysize = sizeof(AggHashEntryData) +
|
|
(numAggs - 1) *sizeof(AggStatePerGroupData);
|
|
/* Account for hashtable overhead */
|
|
entrysize += 2 * sizeof(void *);
|
|
entrysize = MAXALIGN(entrysize);
|
|
return entrysize;
|
|
}
|
|
|
|
/*
|
|
* Find or create a hashtable entry for the tuple group containing the
|
|
* given tuple.
|
|
*
|
|
* When called, CurrentMemoryContext should be the per-query context.
|
|
*/
|
|
static AggHashEntry
|
|
lookup_hash_entry(AggState *aggstate, TupleTableSlot *slot)
|
|
{
|
|
AggHashEntry entry;
|
|
bool isnew;
|
|
|
|
entry = (AggHashEntry) LookupTupleHashEntry(aggstate->hashtable,
|
|
slot,
|
|
&isnew);
|
|
|
|
if (isnew)
|
|
{
|
|
/* initialize aggregates for new tuple group */
|
|
initialize_aggregates(aggstate, aggstate->peragg, entry->pergroup);
|
|
}
|
|
|
|
return entry;
|
|
}
|
|
|
|
/*
|
|
* ExecAgg -
|
|
*
|
|
* ExecAgg receives tuples from its outer subplan and aggregates over
|
|
* the appropriate attribute for each aggregate function use (Aggref
|
|
* node) appearing in the targetlist or qual of the node. The number
|
|
* of tuples to aggregate over depends on whether grouped or plain
|
|
* aggregation is selected. In grouped aggregation, we produce a result
|
|
* row for each group; in plain aggregation there's a single result row
|
|
* for the whole query. In either case, the value of each aggregate is
|
|
* stored in the expression context to be used when ExecProject evaluates
|
|
* the result tuple.
|
|
*/
|
|
TupleTableSlot *
|
|
ExecAgg(AggState *node)
|
|
{
|
|
if (node->agg_done)
|
|
return NULL;
|
|
|
|
if (((Agg *) node->ss.ps.plan)->aggstrategy == AGG_HASHED)
|
|
{
|
|
if (!node->table_filled)
|
|
agg_fill_hash_table(node);
|
|
return agg_retrieve_hash_table(node);
|
|
}
|
|
else
|
|
return agg_retrieve_direct(node);
|
|
}
|
|
|
|
/*
|
|
* ExecAgg for non-hashed case
|
|
*/
|
|
static TupleTableSlot *
|
|
agg_retrieve_direct(AggState *aggstate)
|
|
{
|
|
Agg *node = (Agg *) aggstate->ss.ps.plan;
|
|
PlanState *outerPlan;
|
|
ExprContext *econtext;
|
|
ExprContext *tmpcontext;
|
|
ProjectionInfo *projInfo;
|
|
Datum *aggvalues;
|
|
bool *aggnulls;
|
|
AggStatePerAgg peragg;
|
|
AggStatePerGroup pergroup;
|
|
TupleTableSlot *outerslot;
|
|
TupleTableSlot *firstSlot;
|
|
int aggno;
|
|
|
|
/*
|
|
* get state info from node
|
|
*/
|
|
outerPlan = outerPlanState(aggstate);
|
|
/* econtext is the per-output-tuple expression context */
|
|
econtext = aggstate->ss.ps.ps_ExprContext;
|
|
aggvalues = econtext->ecxt_aggvalues;
|
|
aggnulls = econtext->ecxt_aggnulls;
|
|
/* tmpcontext is the per-input-tuple expression context */
|
|
tmpcontext = aggstate->tmpcontext;
|
|
projInfo = aggstate->ss.ps.ps_ProjInfo;
|
|
peragg = aggstate->peragg;
|
|
pergroup = aggstate->pergroup;
|
|
firstSlot = aggstate->ss.ss_ScanTupleSlot;
|
|
|
|
/*
|
|
* We loop retrieving groups until we find one matching
|
|
* aggstate->ss.ps.qual
|
|
*/
|
|
while (!aggstate->agg_done)
|
|
{
|
|
/*
|
|
* If we don't already have the first tuple of the new group,
|
|
* fetch it from the outer plan.
|
|
*/
|
|
if (aggstate->grp_firstTuple == NULL)
|
|
{
|
|
outerslot = ExecProcNode(outerPlan);
|
|
if (!TupIsNull(outerslot))
|
|
{
|
|
/*
|
|
* Make a copy of the first input tuple; we will use this
|
|
* for comparisons (in group mode) and for projection.
|
|
*/
|
|
aggstate->grp_firstTuple = ExecCopySlotTuple(outerslot);
|
|
}
|
|
else
|
|
{
|
|
/* outer plan produced no tuples at all */
|
|
aggstate->agg_done = true;
|
|
/* If we are grouping, we should produce no tuples too */
|
|
if (node->aggstrategy != AGG_PLAIN)
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Clear the per-output-tuple context for each group
|
|
*/
|
|
ResetExprContext(econtext);
|
|
|
|
/*
|
|
* Initialize working state for a new input tuple group
|
|
*/
|
|
initialize_aggregates(aggstate, peragg, pergroup);
|
|
|
|
if (aggstate->grp_firstTuple != NULL)
|
|
{
|
|
/*
|
|
* Store the copied first input tuple in the tuple table slot
|
|
* reserved for it. The tuple will be deleted when it is
|
|
* cleared from the slot.
|
|
*/
|
|
ExecStoreTuple(aggstate->grp_firstTuple,
|
|
firstSlot,
|
|
InvalidBuffer,
|
|
true);
|
|
aggstate->grp_firstTuple = NULL; /* don't keep two pointers */
|
|
|
|
/* set up for first advance_aggregates call */
|
|
tmpcontext->ecxt_scantuple = firstSlot;
|
|
|
|
/*
|
|
* Process each outer-plan tuple, and then fetch the next one,
|
|
* until we exhaust the outer plan or cross a group boundary.
|
|
*/
|
|
for (;;)
|
|
{
|
|
advance_aggregates(aggstate, pergroup);
|
|
|
|
/* Reset per-input-tuple context after each tuple */
|
|
ResetExprContext(tmpcontext);
|
|
|
|
outerslot = ExecProcNode(outerPlan);
|
|
if (TupIsNull(outerslot))
|
|
{
|
|
/* no more outer-plan tuples available */
|
|
aggstate->agg_done = true;
|
|
break;
|
|
}
|
|
/* set up for next advance_aggregates call */
|
|
tmpcontext->ecxt_scantuple = outerslot;
|
|
|
|
/*
|
|
* If we are grouping, check whether we've crossed a group
|
|
* boundary.
|
|
*/
|
|
if (node->aggstrategy == AGG_SORTED)
|
|
{
|
|
if (!execTuplesMatch(firstSlot,
|
|
outerslot,
|
|
node->numCols, node->grpColIdx,
|
|
aggstate->eqfunctions,
|
|
tmpcontext->ecxt_per_tuple_memory))
|
|
{
|
|
/*
|
|
* Save the first input tuple of the next group.
|
|
*/
|
|
aggstate->grp_firstTuple = ExecCopySlotTuple(outerslot);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Done scanning input tuple group. Finalize each aggregate
|
|
* calculation, and stash results in the per-output-tuple context.
|
|
*/
|
|
for (aggno = 0; aggno < aggstate->numaggs; aggno++)
|
|
{
|
|
AggStatePerAgg peraggstate = &peragg[aggno];
|
|
AggStatePerGroup pergroupstate = &pergroup[aggno];
|
|
|
|
if (peraggstate->aggref->aggdistinct)
|
|
process_sorted_aggregate(aggstate, peraggstate, pergroupstate);
|
|
|
|
finalize_aggregate(aggstate, peraggstate, pergroupstate,
|
|
&aggvalues[aggno], &aggnulls[aggno]);
|
|
}
|
|
|
|
/*
|
|
* If we have no first tuple (ie, the outerPlan didn't return
|
|
* anything), create a dummy all-nulls input tuple for use by
|
|
* ExecQual/ExecProject. 99.44% of the time this is a waste of
|
|
* cycles, because ordinarily the projected output tuple's
|
|
* targetlist cannot contain any direct (non-aggregated)
|
|
* references to input columns, so the dummy tuple will not be
|
|
* referenced. However there are special cases where this isn't so
|
|
* --- in particular an UPDATE involving an aggregate will have a
|
|
* targetlist reference to ctid. We need to return a null for
|
|
* ctid in that situation, not coredump.
|
|
*
|
|
* The values returned for the aggregates will be the initial values
|
|
* of the transition functions.
|
|
*/
|
|
if (TupIsNull(firstSlot))
|
|
{
|
|
/* Should only happen in non-grouped mode */
|
|
Assert(node->aggstrategy == AGG_PLAIN);
|
|
Assert(aggstate->agg_done);
|
|
|
|
ExecStoreAllNullTuple(firstSlot);
|
|
}
|
|
|
|
/*
|
|
* Use the representative input tuple for any references to
|
|
* non-aggregated input columns in the qual and tlist.
|
|
*/
|
|
econtext->ecxt_scantuple = firstSlot;
|
|
|
|
/*
|
|
* Check the qual (HAVING clause); if the group does not match,
|
|
* ignore it and loop back to try to process another group.
|
|
*/
|
|
if (ExecQual(aggstate->ss.ps.qual, econtext, false))
|
|
{
|
|
/*
|
|
* Form and return a projection tuple using the aggregate
|
|
* results and the representative input tuple. Note we do not
|
|
* support aggregates returning sets ...
|
|
*/
|
|
return ExecProject(projInfo, NULL);
|
|
}
|
|
}
|
|
|
|
/* No more groups */
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* ExecAgg for hashed case: phase 1, read input and build hash table
|
|
*/
|
|
static void
|
|
agg_fill_hash_table(AggState *aggstate)
|
|
{
|
|
PlanState *outerPlan;
|
|
ExprContext *tmpcontext;
|
|
AggHashEntry entry;
|
|
TupleTableSlot *outerslot;
|
|
|
|
/*
|
|
* get state info from node
|
|
*/
|
|
outerPlan = outerPlanState(aggstate);
|
|
/* tmpcontext is the per-input-tuple expression context */
|
|
tmpcontext = aggstate->tmpcontext;
|
|
|
|
/*
|
|
* Process each outer-plan tuple, and then fetch the next one, until
|
|
* we exhaust the outer plan.
|
|
*/
|
|
for (;;)
|
|
{
|
|
outerslot = ExecProcNode(outerPlan);
|
|
if (TupIsNull(outerslot))
|
|
break;
|
|
/* set up for advance_aggregates call */
|
|
tmpcontext->ecxt_scantuple = outerslot;
|
|
|
|
/* Find or build hashtable entry for this tuple's group */
|
|
entry = lookup_hash_entry(aggstate, outerslot);
|
|
|
|
/* Advance the aggregates */
|
|
advance_aggregates(aggstate, entry->pergroup);
|
|
|
|
/* Reset per-input-tuple context after each tuple */
|
|
ResetExprContext(tmpcontext);
|
|
}
|
|
|
|
aggstate->table_filled = true;
|
|
/* Initialize to walk the hash table */
|
|
ResetTupleHashIterator(aggstate->hashtable, &aggstate->hashiter);
|
|
}
|
|
|
|
/*
|
|
* ExecAgg for hashed case: phase 2, retrieving groups from hash table
|
|
*/
|
|
static TupleTableSlot *
|
|
agg_retrieve_hash_table(AggState *aggstate)
|
|
{
|
|
ExprContext *econtext;
|
|
ProjectionInfo *projInfo;
|
|
Datum *aggvalues;
|
|
bool *aggnulls;
|
|
AggStatePerAgg peragg;
|
|
AggStatePerGroup pergroup;
|
|
AggHashEntry entry;
|
|
TupleTableSlot *firstSlot;
|
|
int aggno;
|
|
|
|
/*
|
|
* get state info from node
|
|
*/
|
|
/* econtext is the per-output-tuple expression context */
|
|
econtext = aggstate->ss.ps.ps_ExprContext;
|
|
aggvalues = econtext->ecxt_aggvalues;
|
|
aggnulls = econtext->ecxt_aggnulls;
|
|
projInfo = aggstate->ss.ps.ps_ProjInfo;
|
|
peragg = aggstate->peragg;
|
|
firstSlot = aggstate->ss.ss_ScanTupleSlot;
|
|
|
|
/*
|
|
* We loop retrieving groups until we find one satisfying
|
|
* aggstate->ss.ps.qual
|
|
*/
|
|
while (!aggstate->agg_done)
|
|
{
|
|
/*
|
|
* Find the next entry in the hash table
|
|
*/
|
|
entry = (AggHashEntry) ScanTupleHashTable(&aggstate->hashiter);
|
|
if (entry == NULL)
|
|
{
|
|
/* No more entries in hashtable, so done */
|
|
aggstate->agg_done = TRUE;
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Clear the per-output-tuple context for each group
|
|
*/
|
|
ResetExprContext(econtext);
|
|
|
|
/*
|
|
* Store the copied first input tuple in the tuple table slot
|
|
* reserved for it, so that it can be used in ExecProject.
|
|
*/
|
|
ExecStoreTuple(entry->shared.firstTuple,
|
|
firstSlot,
|
|
InvalidBuffer,
|
|
false);
|
|
|
|
pergroup = entry->pergroup;
|
|
|
|
/*
|
|
* Finalize each aggregate calculation, and stash results in the
|
|
* per-output-tuple context.
|
|
*/
|
|
for (aggno = 0; aggno < aggstate->numaggs; aggno++)
|
|
{
|
|
AggStatePerAgg peraggstate = &peragg[aggno];
|
|
AggStatePerGroup pergroupstate = &pergroup[aggno];
|
|
|
|
Assert(!peraggstate->aggref->aggdistinct);
|
|
finalize_aggregate(aggstate, peraggstate, pergroupstate,
|
|
&aggvalues[aggno], &aggnulls[aggno]);
|
|
}
|
|
|
|
/*
|
|
* Use the representative input tuple for any references to
|
|
* non-aggregated input columns in the qual and tlist.
|
|
*/
|
|
econtext->ecxt_scantuple = firstSlot;
|
|
|
|
/*
|
|
* Check the qual (HAVING clause); if the group does not match,
|
|
* ignore it and loop back to try to process another group.
|
|
*/
|
|
if (ExecQual(aggstate->ss.ps.qual, econtext, false))
|
|
{
|
|
/*
|
|
* Form and return a projection tuple using the aggregate
|
|
* results and the representative input tuple. Note we do not
|
|
* support aggregates returning sets ...
|
|
*/
|
|
return ExecProject(projInfo, NULL);
|
|
}
|
|
}
|
|
|
|
/* No more groups */
|
|
return NULL;
|
|
}
|
|
|
|
/* -----------------
|
|
* ExecInitAgg
|
|
*
|
|
* Creates the run-time information for the agg node produced by the
|
|
* planner and initializes its outer subtree
|
|
* -----------------
|
|
*/
|
|
AggState *
|
|
ExecInitAgg(Agg *node, EState *estate)
|
|
{
|
|
AggState *aggstate;
|
|
AggStatePerAgg peragg;
|
|
Plan *outerPlan;
|
|
ExprContext *econtext;
|
|
int numaggs,
|
|
aggno;
|
|
ListCell *l;
|
|
|
|
/*
|
|
* create state structure
|
|
*/
|
|
aggstate = makeNode(AggState);
|
|
aggstate->ss.ps.plan = (Plan *) node;
|
|
aggstate->ss.ps.state = estate;
|
|
|
|
aggstate->aggs = NIL;
|
|
aggstate->numaggs = 0;
|
|
aggstate->eqfunctions = NULL;
|
|
aggstate->hashfunctions = NULL;
|
|
aggstate->peragg = NULL;
|
|
aggstate->agg_done = false;
|
|
aggstate->pergroup = NULL;
|
|
aggstate->grp_firstTuple = NULL;
|
|
aggstate->hashtable = NULL;
|
|
|
|
/*
|
|
* Create expression contexts. We need two, one for per-input-tuple
|
|
* processing and one for per-output-tuple processing. We cheat a
|
|
* little by using ExecAssignExprContext() to build both.
|
|
*/
|
|
ExecAssignExprContext(estate, &aggstate->ss.ps);
|
|
aggstate->tmpcontext = aggstate->ss.ps.ps_ExprContext;
|
|
ExecAssignExprContext(estate, &aggstate->ss.ps);
|
|
|
|
/*
|
|
* We also need a long-lived memory context for holding hashtable data
|
|
* structures and transition values. NOTE: the details of what is
|
|
* stored in aggcontext and what is stored in the regular per-query
|
|
* memory context are driven by a simple decision: we want to reset
|
|
* the aggcontext in ExecReScanAgg to recover no-longer-wanted space.
|
|
*/
|
|
aggstate->aggcontext =
|
|
AllocSetContextCreate(CurrentMemoryContext,
|
|
"AggContext",
|
|
ALLOCSET_DEFAULT_MINSIZE,
|
|
ALLOCSET_DEFAULT_INITSIZE,
|
|
ALLOCSET_DEFAULT_MAXSIZE);
|
|
|
|
#define AGG_NSLOTS 2
|
|
|
|
/*
|
|
* tuple table initialization
|
|
*/
|
|
ExecInitScanTupleSlot(estate, &aggstate->ss);
|
|
ExecInitResultTupleSlot(estate, &aggstate->ss.ps);
|
|
|
|
/*
|
|
* initialize child expressions
|
|
*
|
|
* Note: ExecInitExpr finds Aggrefs for us, and also checks that no aggs
|
|
* contain other agg calls in their arguments. This would make no
|
|
* sense under SQL semantics anyway (and it's forbidden by the spec).
|
|
* Because that is true, we don't need to worry about evaluating the
|
|
* aggs in any particular order.
|
|
*/
|
|
aggstate->ss.ps.targetlist = (List *)
|
|
ExecInitExpr((Expr *) node->plan.targetlist,
|
|
(PlanState *) aggstate);
|
|
aggstate->ss.ps.qual = (List *)
|
|
ExecInitExpr((Expr *) node->plan.qual,
|
|
(PlanState *) aggstate);
|
|
|
|
/*
|
|
* initialize child nodes
|
|
*/
|
|
outerPlan = outerPlan(node);
|
|
outerPlanState(aggstate) = ExecInitNode(outerPlan, estate);
|
|
|
|
/*
|
|
* initialize source tuple type.
|
|
*/
|
|
ExecAssignScanTypeFromOuterPlan(&aggstate->ss);
|
|
|
|
/*
|
|
* Initialize result tuple type and projection info.
|
|
*/
|
|
ExecAssignResultTypeFromTL(&aggstate->ss.ps);
|
|
ExecAssignProjectionInfo(&aggstate->ss.ps);
|
|
|
|
/*
|
|
* get the count of aggregates in targetlist and quals
|
|
*/
|
|
numaggs = aggstate->numaggs;
|
|
Assert(numaggs == list_length(aggstate->aggs));
|
|
if (numaggs <= 0)
|
|
{
|
|
/*
|
|
* This is not an error condition: we might be using the Agg node
|
|
* just to do hash-based grouping. Even in the regular case,
|
|
* constant-expression simplification could optimize away all of
|
|
* the Aggrefs in the targetlist and qual. So keep going, but
|
|
* force local copy of numaggs positive so that palloc()s below
|
|
* don't choke.
|
|
*/
|
|
numaggs = 1;
|
|
}
|
|
|
|
/*
|
|
* If we are grouping, precompute fmgr lookup data for inner loop. We
|
|
* need both equality and hashing functions to do it by hashing, but
|
|
* only equality if not hashing.
|
|
*/
|
|
if (node->numCols > 0)
|
|
{
|
|
if (node->aggstrategy == AGG_HASHED)
|
|
execTuplesHashPrepare(ExecGetScanType(&aggstate->ss),
|
|
node->numCols,
|
|
node->grpColIdx,
|
|
&aggstate->eqfunctions,
|
|
&aggstate->hashfunctions);
|
|
else
|
|
aggstate->eqfunctions =
|
|
execTuplesMatchPrepare(ExecGetScanType(&aggstate->ss),
|
|
node->numCols,
|
|
node->grpColIdx);
|
|
}
|
|
|
|
/*
|
|
* Set up aggregate-result storage in the output expr context, and
|
|
* also allocate my private per-agg working storage
|
|
*/
|
|
econtext = aggstate->ss.ps.ps_ExprContext;
|
|
econtext->ecxt_aggvalues = (Datum *) palloc0(sizeof(Datum) * numaggs);
|
|
econtext->ecxt_aggnulls = (bool *) palloc0(sizeof(bool) * numaggs);
|
|
|
|
peragg = (AggStatePerAgg) palloc0(sizeof(AggStatePerAggData) * numaggs);
|
|
aggstate->peragg = peragg;
|
|
|
|
if (node->aggstrategy == AGG_HASHED)
|
|
{
|
|
build_hash_table(aggstate);
|
|
aggstate->table_filled = false;
|
|
}
|
|
else
|
|
{
|
|
AggStatePerGroup pergroup;
|
|
|
|
pergroup = (AggStatePerGroup) palloc0(sizeof(AggStatePerGroupData) * numaggs);
|
|
aggstate->pergroup = pergroup;
|
|
}
|
|
|
|
/*
|
|
* Perform lookups of aggregate function info, and initialize the
|
|
* unchanging fields of the per-agg data. We also detect duplicate
|
|
* aggregates (for example, "SELECT sum(x) ... HAVING sum(x) > 0").
|
|
* When duplicates are detected, we only make an AggStatePerAgg struct
|
|
* for the first one. The clones are simply pointed at the same
|
|
* result entry by giving them duplicate aggno values.
|
|
*/
|
|
aggno = -1;
|
|
foreach(l, aggstate->aggs)
|
|
{
|
|
AggrefExprState *aggrefstate = (AggrefExprState *) lfirst(l);
|
|
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;
|
|
|
|
/* Planner should have assigned aggregate to correct level */
|
|
Assert(aggref->agglevelsup == 0);
|
|
|
|
/* Look for a previous duplicate aggregate */
|
|
for (i = 0; i <= aggno; i++)
|
|
{
|
|
if (equal(aggref, peragg[i].aggref) &&
|
|
!contain_volatile_functions((Node *) aggref))
|
|
break;
|
|
}
|
|
if (i <= aggno)
|
|
{
|
|
/* Found a match to an existing entry, so just mark it */
|
|
aggrefstate->aggno = i;
|
|
continue;
|
|
}
|
|
|
|
/* Nope, so assign a new PerAgg record */
|
|
peraggstate = &peragg[++aggno];
|
|
|
|
/* Mark Aggref state node with assigned index in the result array */
|
|
aggrefstate->aggno = aggno;
|
|
|
|
/* Fill in the peraggstate data */
|
|
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);
|
|
if (!HeapTupleIsValid(aggTuple))
|
|
elog(ERROR, "cache lookup failed for aggregate %u",
|
|
aggref->aggfnoid);
|
|
aggform = (Form_pg_aggregate) GETSTRUCT(aggTuple);
|
|
|
|
/* Check permission to call aggregate function */
|
|
aclresult = pg_proc_aclcheck(aggref->aggfnoid, GetUserId(),
|
|
ACL_EXECUTE);
|
|
if (aclresult != ACLCHECK_OK)
|
|
aclcheck_error(aclresult, ACL_KIND_PROC,
|
|
get_func_name(aggref->aggfnoid));
|
|
|
|
peraggstate->transfn_oid = transfn_oid = aggform->aggtransfn;
|
|
peraggstate->finalfn_oid = finalfn_oid = aggform->aggfinalfn;
|
|
|
|
/* Check that aggregate owner has permission to call component fns */
|
|
{
|
|
HeapTuple procTuple;
|
|
AclId aggOwner;
|
|
|
|
procTuple = SearchSysCache(PROCOID,
|
|
ObjectIdGetDatum(aggref->aggfnoid),
|
|
0, 0, 0);
|
|
if (!HeapTupleIsValid(procTuple))
|
|
elog(ERROR, "cache lookup failed for function %u",
|
|
aggref->aggfnoid);
|
|
aggOwner = ((Form_pg_proc) GETSTRUCT(procTuple))->proowner;
|
|
ReleaseSysCache(procTuple);
|
|
|
|
aclresult = pg_proc_aclcheck(transfn_oid, aggOwner,
|
|
ACL_EXECUTE);
|
|
if (aclresult != ACLCHECK_OK)
|
|
aclcheck_error(aclresult, ACL_KIND_PROC,
|
|
get_func_name(transfn_oid));
|
|
if (OidIsValid(finalfn_oid))
|
|
{
|
|
aclresult = pg_proc_aclcheck(finalfn_oid, aggOwner,
|
|
ACL_EXECUTE);
|
|
if (aclresult != ACLCHECK_OK)
|
|
aclcheck_error(aclresult, ACL_KIND_PROC,
|
|
get_func_name(finalfn_oid));
|
|
}
|
|
}
|
|
|
|
/* 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;
|
|
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]);
|
|
pfree(agg_arg_types);
|
|
}
|
|
|
|
/* 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(aggtranstype,
|
|
&peraggstate->transtypeLen,
|
|
&peraggstate->transtypeByVal);
|
|
|
|
/*
|
|
* 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,
|
|
aggtranstype);
|
|
|
|
/*
|
|
* If the transfn is strict and the initval is NULL, make sure
|
|
* input type and transtype are the same (or at least binary-
|
|
* compatible), so that it's OK to use the first input value as
|
|
* the initial transValue. This should have been checked at agg
|
|
* definition time, but just in case...
|
|
*/
|
|
if (peraggstate->transfn.fn_strict && peraggstate->initValueIsNull)
|
|
{
|
|
if (!IsBinaryCoercible(inputType, aggtranstype))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
|
|
errmsg("aggregate %u needs to have compatible input type and transition type",
|
|
aggref->aggfnoid)));
|
|
}
|
|
|
|
if (aggref->aggdistinct)
|
|
{
|
|
Oid eq_function;
|
|
|
|
/* We don't implement DISTINCT aggs in the HASHED case */
|
|
Assert(node->aggstrategy != AGG_HASHED);
|
|
|
|
peraggstate->inputType = inputType;
|
|
get_typlenbyval(inputType,
|
|
&peraggstate->inputtypeLen,
|
|
&peraggstate->inputtypeByVal);
|
|
|
|
eq_function = equality_oper_funcid(inputType);
|
|
fmgr_info(eq_function, &(peraggstate->equalfn));
|
|
peraggstate->sortOperator = ordering_oper_opid(inputType);
|
|
peraggstate->sortstate = NULL;
|
|
}
|
|
|
|
ReleaseSysCache(aggTuple);
|
|
}
|
|
|
|
/* Update numaggs to match number of unique aggregates found */
|
|
aggstate->numaggs = aggno + 1;
|
|
|
|
return aggstate;
|
|
}
|
|
|
|
static Datum
|
|
GetAggInitVal(Datum textInitVal, Oid transtype)
|
|
{
|
|
Oid typinput,
|
|
typioparam;
|
|
char *strInitVal;
|
|
Datum initVal;
|
|
|
|
getTypeInputInfo(transtype, &typinput, &typioparam);
|
|
strInitVal = DatumGetCString(DirectFunctionCall1(textout, textInitVal));
|
|
initVal = OidFunctionCall3(typinput,
|
|
CStringGetDatum(strInitVal),
|
|
ObjectIdGetDatum(typioparam),
|
|
Int32GetDatum(-1));
|
|
pfree(strInitVal);
|
|
return initVal;
|
|
}
|
|
|
|
int
|
|
ExecCountSlotsAgg(Agg *node)
|
|
{
|
|
return ExecCountSlotsNode(outerPlan(node)) +
|
|
ExecCountSlotsNode(innerPlan(node)) +
|
|
AGG_NSLOTS;
|
|
}
|
|
|
|
void
|
|
ExecEndAgg(AggState *node)
|
|
{
|
|
PlanState *outerPlan;
|
|
int aggno;
|
|
|
|
/* Make sure we have closed any open tuplesorts */
|
|
for (aggno = 0; aggno < node->numaggs; aggno++)
|
|
{
|
|
AggStatePerAgg peraggstate = &node->peragg[aggno];
|
|
|
|
if (peraggstate->sortstate)
|
|
tuplesort_end(peraggstate->sortstate);
|
|
}
|
|
|
|
/*
|
|
* Free both the expr contexts.
|
|
*/
|
|
ExecFreeExprContext(&node->ss.ps);
|
|
node->ss.ps.ps_ExprContext = node->tmpcontext;
|
|
ExecFreeExprContext(&node->ss.ps);
|
|
|
|
/* clean up tuple table */
|
|
ExecClearTuple(node->ss.ss_ScanTupleSlot);
|
|
|
|
MemoryContextDelete(node->aggcontext);
|
|
|
|
outerPlan = outerPlanState(node);
|
|
ExecEndNode(outerPlan);
|
|
}
|
|
|
|
void
|
|
ExecReScanAgg(AggState *node, ExprContext *exprCtxt)
|
|
{
|
|
ExprContext *econtext = node->ss.ps.ps_ExprContext;
|
|
int aggno;
|
|
|
|
node->agg_done = false;
|
|
|
|
if (((Agg *) node->ss.ps.plan)->aggstrategy == AGG_HASHED)
|
|
{
|
|
/*
|
|
* In the hashed case, if we haven't yet built the hash table then
|
|
* we can just return; nothing done yet, so nothing to undo. If
|
|
* subnode's chgParam is not NULL then it will be re-scanned by
|
|
* ExecProcNode, else no reason to re-scan it at all.
|
|
*/
|
|
if (!node->table_filled)
|
|
return;
|
|
|
|
/*
|
|
* If we do have the hash table and the subplan does not have any
|
|
* parameter changes, then we can just rescan the existing hash
|
|
* table; no need to build it again.
|
|
*/
|
|
if (((PlanState *) node)->lefttree->chgParam == NULL)
|
|
{
|
|
ResetTupleHashIterator(node->hashtable, &node->hashiter);
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* Make sure we have closed any open tuplesorts */
|
|
for (aggno = 0; aggno < node->numaggs; aggno++)
|
|
{
|
|
AggStatePerAgg peraggstate = &node->peragg[aggno];
|
|
|
|
if (peraggstate->sortstate)
|
|
tuplesort_end(peraggstate->sortstate);
|
|
peraggstate->sortstate = NULL;
|
|
}
|
|
|
|
/* Release first tuple of group, if we have made a copy */
|
|
if (node->grp_firstTuple != NULL)
|
|
{
|
|
heap_freetuple(node->grp_firstTuple);
|
|
node->grp_firstTuple = NULL;
|
|
}
|
|
|
|
/* Forget current agg values */
|
|
MemSet(econtext->ecxt_aggvalues, 0, sizeof(Datum) * node->numaggs);
|
|
MemSet(econtext->ecxt_aggnulls, 0, sizeof(bool) * node->numaggs);
|
|
|
|
/* Release all temp storage */
|
|
MemoryContextReset(node->aggcontext);
|
|
|
|
if (((Agg *) node->ss.ps.plan)->aggstrategy == AGG_HASHED)
|
|
{
|
|
/* Rebuild an empty hash table */
|
|
build_hash_table(node);
|
|
node->table_filled = false;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Reset the per-group state (in particular, mark transvalues
|
|
* null)
|
|
*/
|
|
MemSet(node->pergroup, 0,
|
|
sizeof(AggStatePerGroupData) * node->numaggs);
|
|
}
|
|
|
|
/*
|
|
* if chgParam of subnode is not null then plan will be re-scanned by
|
|
* first ExecProcNode.
|
|
*/
|
|
if (((PlanState *) node)->lefttree->chgParam == NULL)
|
|
ExecReScan(((PlanState *) node)->lefttree, exprCtxt);
|
|
}
|
|
|
|
/*
|
|
* 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 */
|
|
}
|