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d0e1091cfd
with many NULLs ( inserting of NULL into indexed field cause ERROR: MemoryContextAlloc: invalid request size) As a workaround 'vacuum analyze' could be used. This patch resolves the problem, please upply to 7.1.1 sources and current cvs tree. Oleg Bartunov
380 lines
8.7 KiB
C
380 lines
8.7 KiB
C
/*-------------------------------------------------------------------------
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*
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* gistget.c
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* fetch tuples from a GiST scan.
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*
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*
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*
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* IDENTIFICATION
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* /usr/local/devel/pglite/cvs/src/backend/access/gisr/gistget.c,v 1.9.1 1996/11/21 01:00:00 vadim 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/gist.h"
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#include "executor/execdebug.h"
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static OffsetNumber gistfindnext(IndexScanDesc s, Page p, OffsetNumber n,
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ScanDirection dir);
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static RetrieveIndexResult gistscancache(IndexScanDesc s, ScanDirection dir);
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static RetrieveIndexResult gistfirst(IndexScanDesc s, ScanDirection dir);
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static RetrieveIndexResult gistnext(IndexScanDesc s, ScanDirection dir);
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static ItemPointer gistheapptr(Relation r, ItemPointer itemp);
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static bool gistindex_keytest(IndexTuple tuple, TupleDesc tupdesc,
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int scanKeySize, ScanKey key, GISTSTATE *giststate,
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Relation r, Page p, OffsetNumber offset);
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Datum
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gistgettuple(PG_FUNCTION_ARGS)
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{
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IndexScanDesc s = (IndexScanDesc) PG_GETARG_POINTER(0);
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ScanDirection dir = (ScanDirection) PG_GETARG_INT32(1);
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RetrieveIndexResult res;
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/* if we have it cached in the scan desc, just return the value */
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if ((res = gistscancache(s, dir)) != (RetrieveIndexResult) NULL)
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PG_RETURN_POINTER(res);
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/* not cached, so we'll have to do some work */
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if (ItemPointerIsValid(&(s->currentItemData)))
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res = gistnext(s, dir);
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else
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res = gistfirst(s, dir);
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PG_RETURN_POINTER(res);
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}
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static RetrieveIndexResult
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gistfirst(IndexScanDesc s, ScanDirection dir)
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{
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Buffer b;
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Page p;
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OffsetNumber n;
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OffsetNumber maxoff;
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RetrieveIndexResult res;
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GISTPageOpaque po;
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GISTScanOpaque so;
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GISTSTACK *stk;
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BlockNumber blk;
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IndexTuple it;
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b = ReadBuffer(s->relation, GISTP_ROOT);
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p = BufferGetPage(b);
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po = (GISTPageOpaque) PageGetSpecialPointer(p);
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so = (GISTScanOpaque) s->opaque;
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for (;;)
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{
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maxoff = PageGetMaxOffsetNumber(p);
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if (ScanDirectionIsBackward(dir))
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n = gistfindnext(s, p, maxoff, dir);
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else
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n = gistfindnext(s, p, FirstOffsetNumber, dir);
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while (n < FirstOffsetNumber || n > maxoff)
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{
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ReleaseBuffer(b);
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if (so->s_stack == (GISTSTACK *) NULL)
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return (RetrieveIndexResult) NULL;
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stk = so->s_stack;
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b = ReadBuffer(s->relation, stk->gs_blk);
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p = BufferGetPage(b);
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po = (GISTPageOpaque) PageGetSpecialPointer(p);
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maxoff = PageGetMaxOffsetNumber(p);
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if (ScanDirectionIsBackward(dir))
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n = OffsetNumberPrev(stk->gs_child);
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else
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n = OffsetNumberNext(stk->gs_child);
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so->s_stack = stk->gs_parent;
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pfree(stk);
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n = gistfindnext(s, p, n, dir);
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}
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if (po->flags & F_LEAF)
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{
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ItemPointerSet(&(s->currentItemData), BufferGetBlockNumber(b), n);
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it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
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res = FormRetrieveIndexResult(&(s->currentItemData), &(it->t_tid));
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ReleaseBuffer(b);
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return res;
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}
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else
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{
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stk = (GISTSTACK *) palloc(sizeof(GISTSTACK));
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stk->gs_child = n;
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stk->gs_blk = BufferGetBlockNumber(b);
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stk->gs_parent = so->s_stack;
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so->s_stack = stk;
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it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
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blk = ItemPointerGetBlockNumber(&(it->t_tid));
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ReleaseBuffer(b);
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b = ReadBuffer(s->relation, blk);
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p = BufferGetPage(b);
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po = (GISTPageOpaque) PageGetSpecialPointer(p);
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}
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}
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}
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static RetrieveIndexResult
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gistnext(IndexScanDesc s, ScanDirection dir)
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{
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Buffer b;
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Page p;
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OffsetNumber n;
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OffsetNumber maxoff;
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RetrieveIndexResult res;
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GISTPageOpaque po;
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GISTScanOpaque so;
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GISTSTACK *stk;
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BlockNumber blk;
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IndexTuple it;
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blk = ItemPointerGetBlockNumber(&(s->currentItemData));
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n = ItemPointerGetOffsetNumber(&(s->currentItemData));
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if (ScanDirectionIsForward(dir))
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n = OffsetNumberNext(n);
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else
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n = OffsetNumberPrev(n);
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b = ReadBuffer(s->relation, blk);
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p = BufferGetPage(b);
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po = (GISTPageOpaque) PageGetSpecialPointer(p);
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so = (GISTScanOpaque) s->opaque;
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for (;;)
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{
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maxoff = PageGetMaxOffsetNumber(p);
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n = gistfindnext(s, p, n, dir);
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while (n < FirstOffsetNumber || n > maxoff)
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{
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ReleaseBuffer(b);
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if (so->s_stack == (GISTSTACK *) NULL)
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return (RetrieveIndexResult) NULL;
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stk = so->s_stack;
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b = ReadBuffer(s->relation, stk->gs_blk);
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p = BufferGetPage(b);
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maxoff = PageGetMaxOffsetNumber(p);
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po = (GISTPageOpaque) PageGetSpecialPointer(p);
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if (ScanDirectionIsBackward(dir))
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n = OffsetNumberPrev(stk->gs_child);
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else
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n = OffsetNumberNext(stk->gs_child);
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so->s_stack = stk->gs_parent;
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pfree(stk);
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n = gistfindnext(s, p, n, dir);
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}
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if (po->flags & F_LEAF)
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{
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ItemPointerSet(&(s->currentItemData), BufferGetBlockNumber(b), n);
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it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
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res = FormRetrieveIndexResult(&(s->currentItemData), &(it->t_tid));
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ReleaseBuffer(b);
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return res;
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}
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else
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{
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stk = (GISTSTACK *) palloc(sizeof(GISTSTACK));
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stk->gs_child = n;
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stk->gs_blk = BufferGetBlockNumber(b);
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stk->gs_parent = so->s_stack;
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so->s_stack = stk;
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it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
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blk = ItemPointerGetBlockNumber(&(it->t_tid));
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ReleaseBuffer(b);
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b = ReadBuffer(s->relation, blk);
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p = BufferGetPage(b);
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po = (GISTPageOpaque) PageGetSpecialPointer(p);
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if (ScanDirectionIsBackward(dir))
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n = PageGetMaxOffsetNumber(p);
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else
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n = FirstOffsetNumber;
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}
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}
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}
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/* Similar to index_keytest, but decompresses the key in the IndexTuple */
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static bool
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gistindex_keytest(IndexTuple tuple,
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TupleDesc tupdesc,
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int scanKeySize,
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ScanKey key,
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GISTSTATE *giststate,
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Relation r,
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Page p,
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OffsetNumber offset)
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{
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bool isNull;
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Datum datum;
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Datum test;
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GISTENTRY de;
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IncrIndexProcessed();
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while (scanKeySize > 0)
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{
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datum = index_getattr(tuple,
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1,
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tupdesc,
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&isNull);
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if (isNull || IndexTupleSize(tuple) == sizeof(IndexTupleData) )
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{
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/* XXX eventually should check if SK_ISNULL */
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return false;
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}
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gistdentryinit(giststate, &de, (char *) datum, r, p, offset,
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IndexTupleSize(tuple) - sizeof(IndexTupleData),
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FALSE);
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if (key[0].sk_flags & SK_COMMUTE)
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{
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test = FunctionCall3(&key[0].sk_func,
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key[0].sk_argument,
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PointerGetDatum(&de),
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ObjectIdGetDatum(key[0].sk_procedure));
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}
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else
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{
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test = FunctionCall3(&key[0].sk_func,
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PointerGetDatum(&de),
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key[0].sk_argument,
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ObjectIdGetDatum(key[0].sk_procedure));
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}
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if ( (char*)de.pred != (char*)datum )
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if ( de.pred ) pfree( de.pred );
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if (DatumGetBool(test) == !!(key[0].sk_flags & SK_NEGATE))
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return false;
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scanKeySize -= 1;
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key++;
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}
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return true;
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}
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static OffsetNumber
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gistfindnext(IndexScanDesc s, Page p, OffsetNumber n, ScanDirection dir)
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{
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OffsetNumber maxoff;
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char *it;
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GISTPageOpaque po;
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GISTScanOpaque so;
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GISTSTATE *giststate;
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maxoff = PageGetMaxOffsetNumber(p);
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po = (GISTPageOpaque) PageGetSpecialPointer(p);
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so = (GISTScanOpaque) s->opaque;
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giststate = so->giststate;
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/*
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* If we modified the index during the scan, we may have a pointer to
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* a ghost tuple, before the scan. If this is the case, back up one.
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*/
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if (so->s_flags & GS_CURBEFORE)
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{
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so->s_flags &= ~GS_CURBEFORE;
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n = OffsetNumberPrev(n);
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}
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while (n >= FirstOffsetNumber && n <= maxoff)
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{
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it = (char *) PageGetItem(p, PageGetItemId(p, n));
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if (gistindex_keytest((IndexTuple) it,
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RelationGetDescr(s->relation),
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s->numberOfKeys, s->keyData, giststate,
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s->relation, p, n))
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break;
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if (ScanDirectionIsBackward(dir))
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n = OffsetNumberPrev(n);
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else
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n = OffsetNumberNext(n);
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}
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return n;
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}
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static RetrieveIndexResult
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gistscancache(IndexScanDesc s, ScanDirection dir)
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{
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RetrieveIndexResult res;
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ItemPointer ip;
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if (!(ScanDirectionIsNoMovement(dir)
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&& ItemPointerIsValid(&(s->currentItemData))))
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{
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return (RetrieveIndexResult) NULL;
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}
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ip = gistheapptr(s->relation, &(s->currentItemData));
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if (ItemPointerIsValid(ip))
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res = FormRetrieveIndexResult(&(s->currentItemData), ip);
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else
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res = (RetrieveIndexResult) NULL;
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pfree(ip);
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return res;
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}
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/*
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* gistheapptr returns the item pointer to the tuple in the heap relation
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* for which itemp is the index relation item pointer.
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*/
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static ItemPointer
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gistheapptr(Relation r, ItemPointer itemp)
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{
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Buffer b;
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Page p;
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IndexTuple it;
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ItemPointer ip;
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OffsetNumber n;
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ip = (ItemPointer) palloc(sizeof(ItemPointerData));
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if (ItemPointerIsValid(itemp))
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{
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b = ReadBuffer(r, ItemPointerGetBlockNumber(itemp));
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p = BufferGetPage(b);
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n = ItemPointerGetOffsetNumber(itemp);
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it = (IndexTuple) PageGetItem(p, PageGetItemId(p, n));
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memmove((char *) ip, (char *) &(it->t_tid),
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sizeof(ItemPointerData));
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ReleaseBuffer(b);
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}
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else
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ItemPointerSetInvalid(ip);
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return ip;
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}
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