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Add SP-GiST (space-partitioned GiST) index access method.

SP-GiST is comparable to GiST in flexibility, but supports non-balanced
partitioned search structures rather than balanced trees.  As described at
PGCon 2011, this new indexing structure can beat GiST in both index build
time and query speed for search problems that it is well matched to.

There are a number of areas that could still use improvement, but at this
point the code seems committable.

Teodor Sigaev and Oleg Bartunov, with considerable revisions by Tom Lane
This commit is contained in:
Tom Lane
2011-12-17 16:41:16 -05:00
parent 19fc0fe3ae
commit 8daeb5ddd6
46 changed files with 10395 additions and 101 deletions

View File

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/*-------------------------------------------------------------------------
*
* spginsert.c
* Externally visible index creation/insertion routines
*
* All the actual insertion logic is in spgdoinsert.c.
*
* Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/backend/access/spgist/spginsert.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/genam.h"
#include "access/spgist_private.h"
#include "catalog/index.h"
#include "miscadmin.h"
#include "storage/bufmgr.h"
#include "storage/smgr.h"
#include "utils/memutils.h"
typedef struct
{
SpGistState spgstate; /* SPGiST's working state */
MemoryContext tmpCtx; /* per-tuple temporary context */
} SpGistBuildState;
/* Callback to process one heap tuple during IndexBuildHeapScan */
static void
spgistBuildCallback(Relation index, HeapTuple htup, Datum *values,
bool *isnull, bool tupleIsAlive, void *state)
{
SpGistBuildState *buildstate = (SpGistBuildState *) state;
/* SPGiST doesn't index nulls */
if (*isnull == false)
{
/* Work in temp context, and reset it after each tuple */
MemoryContext oldCtx = MemoryContextSwitchTo(buildstate->tmpCtx);
spgdoinsert(index, &buildstate->spgstate, &htup->t_self, *values);
MemoryContextSwitchTo(oldCtx);
MemoryContextReset(buildstate->tmpCtx);
}
}
/*
* Build an SP-GiST index.
*/
Datum
spgbuild(PG_FUNCTION_ARGS)
{
Relation heap = (Relation) PG_GETARG_POINTER(0);
Relation index = (Relation) PG_GETARG_POINTER(1);
IndexInfo *indexInfo = (IndexInfo *) PG_GETARG_POINTER(2);
IndexBuildResult *result;
double reltuples;
SpGistBuildState buildstate;
Buffer metabuffer,
rootbuffer;
if (RelationGetNumberOfBlocks(index) != 0)
elog(ERROR, "index \"%s\" already contains data",
RelationGetRelationName(index));
/*
* Initialize the meta page and root page
*/
metabuffer = SpGistNewBuffer(index);
rootbuffer = SpGistNewBuffer(index);
Assert(BufferGetBlockNumber(metabuffer) == SPGIST_METAPAGE_BLKNO);
Assert(BufferGetBlockNumber(rootbuffer) == SPGIST_HEAD_BLKNO);
START_CRIT_SECTION();
SpGistInitMetapage(BufferGetPage(metabuffer));
MarkBufferDirty(metabuffer);
SpGistInitBuffer(rootbuffer, SPGIST_LEAF);
MarkBufferDirty(rootbuffer);
if (RelationNeedsWAL(index))
{
XLogRecPtr recptr;
XLogRecData rdata;
/* WAL data is just the relfilenode */
rdata.data = (char *) &(index->rd_node);
rdata.len = sizeof(RelFileNode);
rdata.buffer = InvalidBuffer;
rdata.next = NULL;
recptr = XLogInsert(RM_SPGIST_ID, XLOG_SPGIST_CREATE_INDEX, &rdata);
PageSetLSN(BufferGetPage(metabuffer), recptr);
PageSetTLI(BufferGetPage(metabuffer), ThisTimeLineID);
PageSetLSN(BufferGetPage(rootbuffer), recptr);
PageSetTLI(BufferGetPage(rootbuffer), ThisTimeLineID);
}
END_CRIT_SECTION();
UnlockReleaseBuffer(metabuffer);
UnlockReleaseBuffer(rootbuffer);
/*
* Now insert all the heap data into the index
*/
initSpGistState(&buildstate.spgstate, index);
buildstate.spgstate.isBuild = true;
buildstate.tmpCtx = AllocSetContextCreate(CurrentMemoryContext,
"SP-GiST build temporary context",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
reltuples = IndexBuildHeapScan(heap, index, indexInfo, true,
spgistBuildCallback, (void *) &buildstate);
MemoryContextDelete(buildstate.tmpCtx);
SpGistUpdateMetaPage(index);
result = (IndexBuildResult *) palloc0(sizeof(IndexBuildResult));
result->heap_tuples = result->index_tuples = reltuples;
PG_RETURN_POINTER(result);
}
/*
* Build an empty SPGiST index in the initialization fork
*/
Datum
spgbuildempty(PG_FUNCTION_ARGS)
{
Relation index = (Relation) PG_GETARG_POINTER(0);
Page page;
/* Construct metapage. */
page = (Page) palloc(BLCKSZ);
SpGistInitMetapage(page);
/* Write the page. If archiving/streaming, XLOG it. */
smgrwrite(index->rd_smgr, INIT_FORKNUM, SPGIST_METAPAGE_BLKNO,
(char *) page, true);
if (XLogIsNeeded())
log_newpage(&index->rd_smgr->smgr_rnode.node, INIT_FORKNUM,
SPGIST_METAPAGE_BLKNO, page);
/* Likewise for the root page. */
SpGistInitPage(page, SPGIST_LEAF);
smgrwrite(index->rd_smgr, INIT_FORKNUM, SPGIST_HEAD_BLKNO,
(char *) page, true);
if (XLogIsNeeded())
log_newpage(&index->rd_smgr->smgr_rnode.node, INIT_FORKNUM,
SPGIST_HEAD_BLKNO, page);
/*
* An immediate sync is required even if we xlog'd the pages, because the
* writes did not go through shared buffers and therefore a concurrent
* checkpoint may have moved the redo pointer past our xlog record.
*/
smgrimmedsync(index->rd_smgr, INIT_FORKNUM);
PG_RETURN_VOID();
}
/*
* Insert one new tuple into an SPGiST index.
*/
Datum
spginsert(PG_FUNCTION_ARGS)
{
Relation index = (Relation) PG_GETARG_POINTER(0);
Datum *values = (Datum *) PG_GETARG_POINTER(1);
bool *isnull = (bool *) PG_GETARG_POINTER(2);
ItemPointer ht_ctid = (ItemPointer) PG_GETARG_POINTER(3);
#ifdef NOT_USED
Relation heapRel = (Relation) PG_GETARG_POINTER(4);
IndexUniqueCheck checkUnique = (IndexUniqueCheck) PG_GETARG_INT32(5);
#endif
SpGistState spgstate;
MemoryContext oldCtx;
MemoryContext insertCtx;
/* SPGiST doesn't index nulls */
if (*isnull)
PG_RETURN_BOOL(false);
insertCtx = AllocSetContextCreate(CurrentMemoryContext,
"SP-GiST insert temporary context",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
oldCtx = MemoryContextSwitchTo(insertCtx);
initSpGistState(&spgstate, index);
spgdoinsert(index, &spgstate, ht_ctid, *values);
SpGistUpdateMetaPage(index);
MemoryContextSwitchTo(oldCtx);
MemoryContextDelete(insertCtx);
/* return false since we've not done any unique check */
PG_RETURN_BOOL(false);
}