diff options
Diffstat (limited to 'src/backend/access/nbtree/nbtscan.c')
| -rw-r--r-- | src/backend/access/nbtree/nbtscan.c | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/src/backend/access/nbtree/nbtscan.c b/src/backend/access/nbtree/nbtscan.c index 8fc6e736c6..7aa9d2ac57 100644 --- a/src/backend/access/nbtree/nbtscan.c +++ b/src/backend/access/nbtree/nbtscan.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/access/nbtree/Attic/nbtscan.c,v 1.14 1998/06/15 19:27:57 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/access/nbtree/Attic/nbtscan.c,v 1.15 1998/07/30 05:04:50 vadim Exp $ * * * NOTES @@ -30,6 +30,7 @@ #include <postgres.h> #include <storage/bufpage.h> +#include <storage/bufmgr.h> #include <access/nbtree.h> typedef struct BTScanListData @@ -145,9 +146,16 @@ _bt_scandel(IndexScanDesc scan, int op, BlockNumber blkno, OffsetNumber offno) { switch (op) { +/* + * Problems occure when current scan page is splitted! + * We saw "Non-functional updates" (ie index tuples were read twice) + * and partial updates ("good" tuples were not read at all) - due to + * losing scan position here. Look @ nbtree.c:btgettuple() + * what we do now... - vadim 07/29/98 case BT_INSERT: _bt_step(scan, &buf, ForwardScanDirection); break; + */ case BT_DELETE: _bt_step(scan, &buf, BackwardScanDirection); break; @@ -156,6 +164,14 @@ _bt_scandel(IndexScanDesc scan, int op, BlockNumber blkno, OffsetNumber offno) /* NOTREACHED */ } so->btso_curbuf = buf; + if (ItemPointerIsValid(current)) + { + Page page = BufferGetPage(buf); + BTItem btitem = (BTItem) PageGetItem(page, + PageGetItemId(page, ItemPointerGetOffsetNumber(current))); + + so->curHeapIptr = btitem->bti_itup.t_tid; + } } current = &(scan->currentMarkData); @@ -173,9 +189,12 @@ _bt_scandel(IndexScanDesc scan, int op, BlockNumber blkno, OffsetNumber offno) buf = so->btso_curbuf; switch (op) { +/* + * ...comments are above... case BT_INSERT: _bt_step(scan, &buf, ForwardScanDirection); break; + */ case BT_DELETE: _bt_step(scan, &buf, BackwardScanDirection); break; @@ -188,6 +207,14 @@ _bt_scandel(IndexScanDesc scan, int op, BlockNumber blkno, OffsetNumber offno) tmp = *current; *current = scan->currentItemData; scan->currentItemData = tmp; + if (ItemPointerIsValid(current)) + { + Page page = BufferGetPage(buf); + BTItem btitem = (BTItem) PageGetItem(page, + PageGetItemId(page, ItemPointerGetOffsetNumber(current))); + + so->mrkHeapIptr = btitem->bti_itup.t_tid; + } } } |