diff options
Diffstat (limited to 'src/backend/access/nbtree/nbtree.c')
| -rw-r--r-- | src/backend/access/nbtree/nbtree.c | 64 |
1 files changed, 33 insertions, 31 deletions
diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c index b1426456241..e49f06b1c38 100644 --- a/src/backend/access/nbtree/nbtree.c +++ b/src/backend/access/nbtree/nbtree.c @@ -12,7 +12,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtree.c,v 1.82 2001/07/15 22:48:16 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtree.c,v 1.83 2001/10/25 05:49:21 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -37,6 +37,7 @@ typedef struct bool haveDead; Relation heapRel; BTSpool *spool; + /* * spool2 is needed only when the index is an unique index. Dead * tuples are put into spool2 instead of spool in order to avoid @@ -58,11 +59,11 @@ bool FixBTree = true; static void _bt_restscan(IndexScanDesc scan); static void btbuildCallback(Relation index, - HeapTuple htup, - Datum *attdata, - char *nulls, - bool tupleIsAlive, - void *state); + HeapTuple htup, + Datum *attdata, + char *nulls, + bool tupleIsAlive, + void *state); /* @@ -134,6 +135,7 @@ btbuild(PG_FUNCTION_ARGS) if (buildstate.usefast) { buildstate.spool = _bt_spoolinit(index, indexInfo->ii_Unique); + /* * Different from spool, the uniqueness isn't checked for spool2. */ @@ -214,7 +216,7 @@ btbuildCallback(Relation index, bool tupleIsAlive, void *state) { - BTBuildState *buildstate = (BTBuildState *) state; + BTBuildState *buildstate = (BTBuildState *) state; IndexTuple itup; BTItem btitem; InsertIndexResult res; @@ -226,9 +228,9 @@ btbuildCallback(Relation index, btitem = _bt_formitem(itup); /* - * if we are doing bottom-up btree build, we insert the index into - * a spool file for subsequent processing. otherwise, we insert - * into the btree. + * if we are doing bottom-up btree build, we insert the index into a + * spool file for subsequent processing. otherwise, we insert into + * the btree. */ if (buildstate->usefast) { @@ -305,7 +307,6 @@ btgettuple(PG_FUNCTION_ARGS) if (ItemPointerIsValid(&(scan->currentItemData))) { - /* * Restore scan position using heap TID returned by previous call * to btgettuple(). _bt_restscan() re-grabs the read lock on the @@ -321,7 +322,7 @@ btgettuple(PG_FUNCTION_ARGS) * Save heap TID to use it in _bt_restscan. Then release the read * lock on the buffer so that we aren't blocking other backends. * - * NOTE: we do keep the pin on the buffer! This is essential to ensure + * NOTE: we do keep the pin on the buffer! This is essential to ensure * that someone else doesn't delete the index entry we are stopped on. */ if (res) @@ -362,7 +363,6 @@ btrescan(PG_FUNCTION_ARGS) #ifdef NOT_USED /* XXX surely it's wrong to ignore this? */ bool fromEnd = PG_GETARG_BOOL(1); - #endif ScanKey scankey = (ScanKey) PG_GETARG_POINTER(2); ItemPointer iptr; @@ -547,7 +547,7 @@ btbulkdelete(PG_FUNCTION_ARGS) IndexBulkDeleteCallback callback = (IndexBulkDeleteCallback) PG_GETARG_POINTER(1); void *callback_state = (void *) PG_GETARG_POINTER(2); IndexBulkDeleteResult *result; - BlockNumber num_pages; + BlockNumber num_pages; double tuples_removed; double num_index_tuples; RetrieveIndexResult res; @@ -559,15 +559,16 @@ btbulkdelete(PG_FUNCTION_ARGS) num_index_tuples = 0; /* - * We use a standard IndexScanDesc scan object, but to speed up the loop, - * we skip most of the wrapper layers of index_getnext and instead call - * _bt_step directly. This implies holding buffer lock on a target page - * throughout the loop over the page's tuples. Initially, we have a read - * lock acquired by _bt_step when we stepped onto the page. If we find - * a tuple we need to delete, we trade in the read lock for an exclusive - * write lock; after that, we hold the write lock until we step off the - * page (fortunately, _bt_relbuf doesn't care which kind of lock it's - * releasing). This should minimize the amount of work needed per page. + * We use a standard IndexScanDesc scan object, but to speed up the + * loop, we skip most of the wrapper layers of index_getnext and + * instead call _bt_step directly. This implies holding buffer lock + * on a target page throughout the loop over the page's tuples. + * Initially, we have a read lock acquired by _bt_step when we stepped + * onto the page. If we find a tuple we need to delete, we trade in + * the read lock for an exclusive write lock; after that, we hold the + * write lock until we step off the page (fortunately, _bt_relbuf + * doesn't care which kind of lock it's releasing). This should + * minimize the amount of work needed per page. */ scan = index_beginscan(rel, false, 0, (ScanKey) NULL); so = (BTScanOpaque) scan->opaque; @@ -579,7 +580,7 @@ btbulkdelete(PG_FUNCTION_ARGS) if (res != NULL) { Buffer buf; - BlockNumber lockedBlock = InvalidBlockNumber; + BlockNumber lockedBlock = InvalidBlockNumber; pfree(res); /* we have the buffer pinned and locked */ @@ -589,11 +590,11 @@ btbulkdelete(PG_FUNCTION_ARGS) do { Page page; - BlockNumber blkno; + BlockNumber blkno; OffsetNumber offnum; BTItem btitem; IndexTuple itup; - ItemPointer htup; + ItemPointer htup; /* current is the next index tuple */ blkno = ItemPointerGetBlockNumber(current); @@ -607,9 +608,10 @@ btbulkdelete(PG_FUNCTION_ARGS) { /* * If this is first deletion on this page, trade in read - * lock for a really-exclusive write lock. Then, step back - * one and re-examine the item, because someone else might - * have inserted an item while we weren't holding the lock! + * lock for a really-exclusive write lock. Then, step + * back one and re-examine the item, because someone else + * might have inserted an item while we weren't holding + * the lock! */ if (blkno != lockedBlock) { @@ -632,8 +634,8 @@ btbulkdelete(PG_FUNCTION_ARGS) * We need to back up the scan one item so that the next * cycle will re-examine the same offnum on this page. * - * For now, just hack the current-item index. Will need - * to be smarter when deletion includes removal of empty + * For now, just hack the current-item index. Will need to + * be smarter when deletion includes removal of empty * index pages. */ current->ip_posid--; |