*
* tuplesort.h
* Generalized tuple sorting routines.
*
* This module handles sorting of heap tuples, index tuples, or single
* Datums (and could easily support other kinds of sortable objects,
* if necessary). It works efficiently for both small and large amounts
* of data. Small amounts are sorted in-memory using qsort(). Large
* amounts are sorted using temporary files and a standard external sort
* algorithm.
*
* Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/utils/tuplesort.h
*
* -------------------------------------------------------------------------
*/
#ifndef TUPLESORT_H
#define TUPLESORT_H
#include "access/itup.h"
#include "executor/tuptable.h"
#include "fmgr.h"
#include "utils/relcache.h"
#include "utils/tuplestore.h"
#include "utils/logtape.h"
* tuplesort.c.
*/
* Private mutable state of tuplesort-parallel-operation. This is allocated
* in shared memory.
*/
struct Sharedsort {
slock_t mutex;
* currentWorker generates ordinal identifier numbers for parallel sort
* workers. These start from 0, and are always gapless.
*
* Workers increment workersFinished to indicate having finished. If this
* is equal to state.nParticipants within the leader, leader is ready to
* merge worker runs.
*/
int currentWorker;
int workersFinished;
SharedFileSet fileset;
int nTapes;
int actualParticipants;
* Tapes array used by workers to report back information needed by the
* leader to concatenate all worker tapes into one for merging
*/
TapeShare tapes[FLEXIBLE_ARRAY_MEMBER];
};
typedef struct Tuplesortstate Tuplesortstate;
typedef struct Sharedsort Sharedsort;
* Tuplesort parallel coordination state, allocated by each participant in
* local memory. Participant caller initializes everything. See usage notes
* below.
*/
typedef struct SortCoordinateData {
bool isWorker;
* Leader-process-passed number of participants known launched (workers
* set this to -1). Includes state within leader needed for it to
* participate as a worker, if any.
*/
int nParticipants;
Sharedsort *sharedsort;
} SortCoordinateData;
typedef struct SortCoordinateData *SortCoordinate;
* We provide multiple interfaces to what is essentially the same code,
* since different callers have different data to be sorted and want to
* specify the sort key information differently. There are two APIs for
* sorting HeapTuples and two more for sorting IndexTuples. Yet another
* API supports sorting bare Datums.
*
* The "heap" API actually stores/sorts MinimalTuples, which means it doesn't
* preserve the system columns (tuple identity and transaction visibility
* info). The sort keys are specified by column numbers within the tuples
* and sort operator OIDs. We save some cycles by passing and returning the
* tuples in TupleTableSlots, rather than forming actual HeapTuples (which'd
* have to be converted to MinimalTuples). This API works well for sorts
* executed as parts of plan trees.
*
* The "cluster" API stores/sorts full HeapTuples including all visibility
* info. The sort keys are specified by reference to a btree index that is
* defined on the relation to be sorted. Note that putheaptuple/getheaptuple
* go with this API, not the "begin_heap" one!
*
* The "index_btree" API stores/sorts IndexTuples (preserving all their
* header fields). The sort keys are specified by a btree index definition.
*
* The "index_hash" API is similar to index_btree, but the tuples are
* actually sorted by their hash codes not the raw data.
*/
extern Tuplesortstate* tuplesort_begin_heap(TupleDesc tupDesc, int nkeys, AttrNumber* attNums, Oid* sortOperators,
Oid* sortCollations, const bool* nullsFirstFlags, int64 workMem, bool randomAccess, int64 maxMem = 0,
int planId = 0, int dop = 1, SortCoordinate coordinate = NULL);
extern Tuplesortstate* tuplesort_begin_cluster(
TupleDesc tupDesc, Relation indexRel, int workMem, bool randomAccess, int maxMem, bool relIsUstore);
extern Tuplesortstate* tuplesort_begin_index_btree(
Relation indexRel, bool enforceUnique, int workMem, SortCoordinate coordinate, bool randomAccess, int maxMem);
extern Tuplesortstate* tuplesort_begin_index_hash(
Relation heapRel, Relation indexRel, uint32 high_mask, uint32 low_mask, uint32 max_buckets,
int workMem, bool randomAccess, int maxMem);
extern Tuplesortstate* tuplesort_begin_datum(
Oid datumType, Oid sortOperator, Oid sortCollation, bool nullsFirstFlag, int workMem, bool randomAccess);
#ifdef PGXC
extern void tuplesort_puttupleslotontape(Tuplesortstate* state, TupleTableSlot* slot);
extern void tuplesort_remoteread_end(Tuplesortstate* state);
#endif
extern void tuplesort_set_bound(Tuplesortstate* state, int64 bound);
extern void tuplesort_set_siblings(Tuplesortstate* state, const int numKeys, const List *internalEntryList);
extern void tuplesort_puttupleslot(Tuplesortstate* state, TupleTableSlot* slot);
extern void TuplesortPutheaptuple(Tuplesortstate* state, HeapTuple tup);
extern void tuplesort_putindextuplevalues(
Tuplesortstate* state, Relation rel, ItemPointer self, Datum* values, const bool* isnull);
extern void tuplesort_putdatum(Tuplesortstate* state, Datum val, bool isNull);
extern void tuplesort_performsort(Tuplesortstate* state);
extern bool tuplesort_gettupleslot(Tuplesortstate* state, bool forward, TupleTableSlot* slot, Datum* abbrev);
extern bool tuplesort_gettupleslot_into_tuplestore(
Tuplesortstate* state, bool forward, TupleTableSlot* slot, Datum* abbrev, Tuplestorestate* tstate);
extern void* tuplesort_getheaptuple(Tuplesortstate* state, bool forward);
extern IndexTuple tuplesort_getindextuple(Tuplesortstate* state, bool forward);
extern bool tuplesort_getdatum(Tuplesortstate* state, bool forward, Datum* val, bool* isNull);
extern void tuplesort_end(Tuplesortstate* state);
extern void tuplesort_get_stats(Tuplesortstate* state, int* sortMethodId, int* spaceTypeId, long* spaceUsed);
extern int tuplesort_merge_order(double allowedMem);
extern Size tuplesort_estimate_shared(int nworkers);
extern void tuplesort_initialize_shared(Sharedsort *shared, int nWorkers);
extern void tuplesort_attach_shared(Sharedsort *shared);
* These routines may only be called if randomAccess was specified 'true'.
* Likewise, backwards scan in gettuple/getdatum is only allowed if
* randomAccess was specified.
*/
extern void tuplesort_rescan(Tuplesortstate* state);
extern void tuplesort_markpos(Tuplesortstate* state);
extern void tuplesort_restorepos(Tuplesortstate* state);
extern void sort_count(Tuplesortstate* state);
extern int64 tuplesort_get_avgwidth(Tuplesortstate* state);
extern bool tuplesort_get_busy_status(Tuplesortstate* state);
extern int tuplesort_get_spread_num(Tuplesortstate* state);
extern bool tuplesort_skiptuples(Tuplesortstate* state, int64 ntuples, bool forward);
extern void UpdateUniqueSQLSortStats(Tuplesortstate* state, TimestampTz* start_time);
* Return the int64 value of tuplesortstate->peakMemorySize
*/
extern int64 tuplesort_get_peak_memory(Tuplesortstate* state);
extern void tuplesort_workerfinish(Sharedsort *shared);
extern void* TuplesortGetSortkeys(Tuplesortstate* state);
extern int TuplesortGetNsortkey(Tuplesortstate* state);
#endif
