diff options
Diffstat (limited to 'src/backend/access/gin/ginget.c')
| -rw-r--r-- | src/backend/access/gin/ginget.c | 79 |
1 files changed, 66 insertions, 13 deletions
diff --git a/src/backend/access/gin/ginget.c b/src/backend/access/gin/ginget.c index 91642f340e9..66949f964c8 100644 --- a/src/backend/access/gin/ginget.c +++ b/src/backend/access/gin/ginget.c @@ -8,7 +8,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/access/gin/ginget.c,v 1.7 2007/02/01 04:16:08 neilc Exp $ + * $PostgreSQL: pgsql/src/backend/access/gin/ginget.c,v 1.8 2007/06/04 15:56:28 teodor Exp $ *------------------------------------------------------------------------- */ @@ -17,22 +17,71 @@ #include "catalog/index.h" #include "utils/memutils.h" -static OffsetNumber -findItemInPage(Page page, ItemPointer item, OffsetNumber off) +static bool +findItemInPage(Page page, ItemPointer item, OffsetNumber *off) { OffsetNumber maxoff = GinPageGetOpaque(page)->maxoff; int res; - for (; off <= maxoff; off++) + if ( GinPageGetOpaque(page)->flags & GIN_DELETED ) + /* page was deleted by concurrent vacuum */ + return false; + + if ( *off > maxoff || *off == InvalidOffsetNumber ) + res = -1; + else + res = compareItemPointers(item, (ItemPointer) GinDataPageGetItem(page, *off)); + + if ( res == 0 ) + { + /* page isn't changed */ + return true; + } + else if ( res > 0 ) { - res = compareItemPointers(item, (ItemPointer) GinDataPageGetItem(page, off)); - Assert(res >= 0); + /* + * some items was added before our position, look further to find + * it or first greater + */ + + (*off)++; + for (; *off <= maxoff; (*off)++) + { + res = compareItemPointers(item, (ItemPointer) GinDataPageGetItem(page, *off)); + + if (res == 0) + return true; - if (res == 0) - return off; + if (res < 0) + { + (*off)--; + return true; + } + } } + else + { + /* + * some items was deleted before our position, look from begining + * to find it or first greater + */ + + for(*off = FirstOffsetNumber; *off<= maxoff; (*off)++) + { + res = compareItemPointers(item, (ItemPointer) GinDataPageGetItem(page, *off)); - return InvalidOffsetNumber; + if ( res == 0 ) + return true; + + if (res < 0) + { + (*off)--; + return true; + } + } + } + + return false; } /* @@ -111,7 +160,7 @@ startScanEntry(Relation index, GinState *ginstate, GinScanEntry entry, bool firs } else if (entry->buffer != InvalidBuffer) { - /* we should find place were we was stopped */ + /* we should find place where we was stopped */ BlockNumber blkno; Page page; @@ -125,7 +174,7 @@ startScanEntry(Relation index, GinState *ginstate, GinScanEntry entry, bool firs page = BufferGetPage(entry->buffer); /* try to find curItem in current buffer */ - if ((entry->offset = findItemInPage(page, &entry->curItem, entry->offset)) != InvalidOffsetNumber) + if ( findItemInPage(page, &entry->curItem, &entry->offset) ) return; /* walk to right */ @@ -136,11 +185,15 @@ startScanEntry(Relation index, GinState *ginstate, GinScanEntry entry, bool firs LockBuffer(entry->buffer, GIN_SHARE); page = BufferGetPage(entry->buffer); - if ((entry->offset = findItemInPage(page, &entry->curItem, FirstOffsetNumber)) != InvalidOffsetNumber) + entry->offset = InvalidOffsetNumber; + if ( findItemInPage(page, &entry->curItem, &entry->offset) ) return; } - elog(ERROR, "Logic error: lost previously founded ItemId"); + /* + * curItem and any greated items was deleted by concurrent vacuum, + * so we finished scan with currrent entry + */ } } |