diff options
Diffstat (limited to 'src/backend/access/nbtree/nbtree.c')
| -rw-r--r-- | src/backend/access/nbtree/nbtree.c | 40 |
1 files changed, 22 insertions, 18 deletions
diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c index 46787e577a..ac46681c61 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 1.91 2002/06/20 20:29:25 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtree.c,v 1.92 2002/09/04 20:31:10 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -315,24 +315,28 @@ btgettuple(PG_FUNCTION_ARGS) * buffer, too. */ _bt_restscan(scan); + /* * Check to see if we should kill the previously-fetched tuple. */ if (scan->kill_prior_tuple) { /* - * Yes, so mark it by setting the LP_DELETE bit in the item flags. + * Yes, so mark it by setting the LP_DELETE bit in the item + * flags. */ offnum = ItemPointerGetOffsetNumber(&(scan->currentItemData)); page = BufferGetPage(so->btso_curbuf); PageGetItemId(page, offnum)->lp_flags |= LP_DELETE; + /* * Since this can be redone later if needed, it's treated the - * same as a commit-hint-bit status update for heap tuples: - * we mark the buffer dirty but don't make a WAL log entry. + * same as a commit-hint-bit status update for heap tuples: we + * mark the buffer dirty but don't make a WAL log entry. */ SetBufferCommitInfoNeedsSave(so->btso_curbuf); } + /* * Now continue the scan. */ @@ -645,15 +649,15 @@ 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 other backends - * might have inserted item(s) while we weren't holding - * the lock! + * back one and re-examine the item, because other + * backends might have inserted item(s) while we weren't + * holding the lock! * * We assume that only concurrent insertions, not deletions, - * can occur while we're not holding the page lock (the caller - * should hold a suitable relation lock to ensure this). - * Therefore, the item we want to delete is either in the - * same slot as before, or some slot to its right. + * can occur while we're not holding the page lock (the + * caller should hold a suitable relation lock to ensure + * this). Therefore, the item we want to delete is either + * in the same slot as before, or some slot to its right. * Rechecking the same slot is necessary and sufficient to * get back in sync after any insertions. */ @@ -675,19 +679,19 @@ btbulkdelete(PG_FUNCTION_ARGS) } /* - * In either case, we now need to back up the scan one item, - * so that the next cycle will re-examine the same offnum on - * this page. + * In either case, we now 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 * index pages. * * We must decrement ip_posid in all cases but one: if the - * page was formerly rightmost but was split while we didn't - * hold the lock, and ip_posid is pointing to item 1, then - * ip_posid now points at the high key not a valid data item. - * In this case we do want to step forward. + * page was formerly rightmost but was split while we + * didn't hold the lock, and ip_posid is pointing to item + * 1, then ip_posid now points at the high key not a valid + * data item. In this case we do want to step forward. */ opaque = (BTPageOpaque) PageGetSpecialPointer(page); if (current->ip_posid >= P_FIRSTDATAKEY(opaque)) |