Viewing file:  nodeAgg.h (10.31 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/*-------------------------------------------------------------------------
*
* nodeAgg.h
* prototypes for nodeAgg.c
*
*
* Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/executor/nodeAgg.h
*
*-------------------------------------------------------------------------
*/
#ifndef NODEAGG_H
#define NODEAGG_H
#include "nodes/execnodes.h"
/*
* AggStatePerTransData - per aggregate state value information
*
* Working state for updating the aggregate's state value, by calling the
* transition function with an input row. This struct does not store the
* information needed to produce the final aggregate result from the transition
* state, that's stored in AggStatePerAggData instead. This separation allows
* multiple aggregate results to be produced from a single state value.
*/
typedef struct AggStatePerTransData
{
/*
* These values are set up during ExecInitAgg() and do not change
* thereafter:
*/
/*
* Link to an Aggref expr this state value is for.
*
* There can be multiple Aggref's sharing the same state value, so long as
* the inputs and transition functions are identical and the final
* functions are not read-write. This points to the first one of them.
*/
Aggref *aggref;
/*
* Is this state value actually being shared by more than one Aggref?
*/
bool aggshared;
/*
* Number of aggregated input columns. This includes ORDER BY expressions
* in both the plain-agg and ordered-set cases. Ordered-set direct args
* are not counted, though.
*/
int numInputs;
/*
* Number of aggregated input columns to pass to the transfn. This
* includes the ORDER BY columns for ordered-set aggs, but not for plain
* aggs. (This doesn't count the transition state value!)
*/
int numTransInputs;
/* Oid of the state transition or combine function */
Oid transfn_oid;
/* Oid of the serialization function or InvalidOid */
Oid serialfn_oid;
/* Oid of the deserialization function or InvalidOid */
Oid deserialfn_oid;
/* Oid of state value's datatype */
Oid aggtranstype;
/*
* fmgr lookup data for transition function or combine function. Note in
* particular that the fn_strict flag is kept here.
*/
FmgrInfo transfn;
/* fmgr lookup data for serialization function */
FmgrInfo serialfn;
/* fmgr lookup data for deserialization function */
FmgrInfo deserialfn;
/* Input collation derived for aggregate */
Oid aggCollation;
/* number of sorting columns */
int numSortCols;
/* number of sorting columns to consider in DISTINCT comparisons */
/* (this is either zero or the same as numSortCols) */
int numDistinctCols;
/* deconstructed sorting information (arrays of length numSortCols) */
AttrNumber *sortColIdx;
Oid *sortOperators;
Oid *sortCollations;
bool *sortNullsFirst;
/*
* Comparators for input columns --- only set/used when aggregate has
* DISTINCT flag. equalfnOne version is used for single-column
* comparisons, equalfnMulti for the case of multiple columns.
*/
FmgrInfo equalfnOne;
ExprState *equalfnMulti;
/*
* initial value from pg_aggregate entry
*/
Datum initValue;
bool initValueIsNull;
/*
* We need the len and byval info for the agg's input and transition data
* types in order to know how to copy/delete values.
*
* Note that the info for the input type is used only when handling
* DISTINCT aggs with just one argument, so there is only one input type.
*/
int16 inputtypeLen,
transtypeLen;
bool inputtypeByVal,
transtypeByVal;
/*
* Slots for holding the evaluated input arguments. These are set up
* during ExecInitAgg() and then used for each input row requiring either
* FILTER or ORDER BY/DISTINCT processing.
*/
TupleTableSlot *sortslot; /* current input tuple */
TupleTableSlot *uniqslot; /* used for multi-column DISTINCT */
TupleDesc sortdesc; /* descriptor of input tuples */
/*
* These values are working state that is initialized at the start of an
* input tuple group and updated for each input tuple.
*
* For a simple (non DISTINCT/ORDER BY) aggregate, we just feed the input
* values straight to the transition function. If it's DISTINCT or
* requires ORDER BY, we pass the input values into a Tuplesort object;
* then at completion of the input tuple group, we scan the sorted values,
* eliminate duplicates if needed, and run the transition function on the
* rest.
*
* We need a separate tuplesort for each grouping set.
*/
Tuplesortstate **sortstates; /* sort objects, if DISTINCT or ORDER BY */
/*
* This field is a pre-initialized FunctionCallInfo struct used for
* calling this aggregate's transfn. We save a few cycles per row by not
* re-initializing the unchanging fields; which isn't much, but it seems
* worth the extra space consumption.
*/
FunctionCallInfoData transfn_fcinfo;
/* Likewise for serialization and deserialization functions */
FunctionCallInfoData serialfn_fcinfo;
FunctionCallInfoData deserialfn_fcinfo;
} AggStatePerTransData;
/*
* AggStatePerAggData - per-aggregate information
*
* This contains the information needed to call the final function, to produce
* a final aggregate result from the state value. If there are multiple
* identical Aggrefs in the query, they can all share the same per-agg data.
*
* These values are set up during ExecInitAgg() and do not change thereafter.
*/
typedef struct AggStatePerAggData
{
/*
* Link to an Aggref expr this state value is for.
*
* There can be multiple identical Aggref's sharing the same per-agg. This
* points to the first one of them.
*/
Aggref *aggref;
/* index to the state value which this agg should use */
int transno;
/* Optional Oid of final function (may be InvalidOid) */
Oid finalfn_oid;
/*
* fmgr lookup data for final function --- only valid when finalfn_oid is
* not InvalidOid.
*/
FmgrInfo finalfn;
/*
* Number of arguments to pass to the finalfn. This is always at least 1
* (the transition state value) plus any ordered-set direct args. If the
* finalfn wants extra args then we pass nulls corresponding to the
* aggregated input columns.
*/
int numFinalArgs;
/* ExprStates for any direct-argument expressions */
List *aggdirectargs;
/*
* We need the len and byval info for the agg's result data type in order
* to know how to copy/delete values.
*/
int16 resulttypeLen;
bool resulttypeByVal;
/*
* "shareable" is false if this agg cannot share state values with other
* aggregates because the final function is read-write.
*/
bool shareable;
} AggStatePerAggData;
/*
* AggStatePerGroupData - per-aggregate-per-group working state
*
* These values are working state that is initialized at the start of
* an input tuple group and updated for each input tuple.
*
* In AGG_PLAIN and AGG_SORTED modes, we have a single array of these
* structs (pointed to by aggstate->pergroup); we re-use the array for
* each input group, if it's AGG_SORTED mode. In AGG_HASHED mode, the
* hash table contains an array of these structs for each tuple group.
*
* Logically, the sortstate field belongs in this struct, but we do not
* keep it here for space reasons: we don't support DISTINCT aggregates
* in AGG_HASHED mode, so there's no reason to use up a pointer field
* in every entry of the hashtable.
*/
typedef struct AggStatePerGroupData
{
#define FIELDNO_AGGSTATEPERGROUPDATA_TRANSVALUE 0
Datum transValue; /* current transition value */
#define FIELDNO_AGGSTATEPERGROUPDATA_TRANSVALUEISNULL 1
bool transValueIsNull;
#define FIELDNO_AGGSTATEPERGROUPDATA_NOTRANSVALUE 2
bool noTransValue; /* true if transValue not set yet */
/*
* Note: noTransValue initially has the same value as transValueIsNull,
* and if true both are cleared to false at the same time. They are not
* the same though: if transfn later returns a NULL, we want to keep that
* NULL and not auto-replace it with a later input value. Only the first
* non-NULL input will be auto-substituted.
*/
} AggStatePerGroupData;
/*
* AggStatePerPhaseData - per-grouping-set-phase state
*
* Grouping sets are divided into "phases", where a single phase can be
* processed in one pass over the input. If there is more than one phase, then
* at the end of input from the current phase, state is reset and another pass
* taken over the data which has been re-sorted in the mean time.
*
* Accordingly, each phase specifies a list of grouping sets and group clause
* information, plus each phase after the first also has a sort order.
*/
typedef struct AggStatePerPhaseData
{
AggStrategy aggstrategy; /* strategy for this phase */
int numsets; /* number of grouping sets (or 0) */
int *gset_lengths; /* lengths of grouping sets */
Bitmapset **grouped_cols; /* column groupings for rollup */
ExprState **eqfunctions; /* expression returning equality, indexed by
* nr of cols to compare */
Agg *aggnode; /* Agg node for phase data */
Sort *sortnode; /* Sort node for input ordering for phase */
ExprState *evaltrans; /* evaluation of transition functions */
} AggStatePerPhaseData;
/*
* AggStatePerHashData - per-hashtable state
*
* When doing grouping sets with hashing, we have one of these for each
* grouping set. (When doing hashing without grouping sets, we have just one of
* them.)
*/
typedef struct AggStatePerHashData
{
TupleHashTable hashtable; /* hash table with one entry per group */
TupleHashIterator hashiter; /* for iterating through hash table */
TupleTableSlot *hashslot; /* slot for loading hash table */
FmgrInfo *hashfunctions; /* per-grouping-field hash fns */
Oid *eqfuncoids; /* per-grouping-field equality fns */
int numCols; /* number of hash key columns */
int numhashGrpCols; /* number of columns in hash table */
int largestGrpColIdx; /* largest col required for hashing */
AttrNumber *hashGrpColIdxInput; /* hash col indices in input slot */
AttrNumber *hashGrpColIdxHash; /* indices in hashtbl tuples */
Agg *aggnode; /* original Agg node, for numGroups etc. */
} AggStatePerHashData;
extern AggState *ExecInitAgg(Agg *node, EState *estate, int eflags);
extern void ExecEndAgg(AggState *node);
extern void ExecReScanAgg(AggState *node);
extern Size hash_agg_entry_size(int numAggs);
extern Datum aggregate_dummy(PG_FUNCTION_ARGS);
#endif /* NODEAGG_H */
|