From b5b337ed772999e03d6a4d4391f4631b6af19d59 Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas Date: Thu, 29 Jan 2015 15:48:02 +0200 Subject: [PATCH 1/1] Fix bug where GIN scan keys were not initialized with gin_fuzzy_search_limit. In 9.4, startScanKey() does a lot of stuff, setting up the requiredEntries array, and you readily get a segfault if it's not initialized. In earlier versions it was harder to trigger incorrect behaviour, because it just set a few flags which were initialized in ginNewScanKey() already. But even on on earlier versions, you would get an assertion failure or missing result rows if the query involved a re-scan of the GIN scan. Reported by Olaf Gawenda, bug #12694, Backpatch to 9.1 and above, 9.0 didn't have the early return in startScan(). --- src/backend/access/gin/ginget.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/src/backend/access/gin/ginget.c b/src/backend/access/gin/ginget.c index 3494d6b..306a3ce 100644 --- a/src/backend/access/gin/ginget.c +++ b/src/backend/access/gin/ginget.c @@ -540,17 +540,28 @@ startScan(IndexScanDesc scan) * supposition isn't true), that total result will not more than * minimal predictNumberResult. */ + bool reduce = true; for (i = 0; i < so->totalentries; i++) + { if (so->entries[i]->predictNumberResult <= so->totalentries * GinFuzzySearchLimit) - return; + { + reduce = false; + break; + } + } - for (i = 0; i < so->totalentries; i++) - if (so->entries[i]->predictNumberResult > so->totalentries * GinFuzzySearchLimit) + if (reduce) + { + for (i = 0; i < so->totalentries; i++) { - so->entries[i]->predictNumberResult /= so->totalentries; - so->entries[i]->reduceResult = TRUE; + if (so->entries[i]->predictNumberResult > so->totalentries * GinFuzzySearchLimit) + { + so->entries[i]->predictNumberResult /= so->totalentries; + so->entries[i]->reduceResult = TRUE; + } } + } } for (i = 0; i < so->nkeys; i++) -- 2.1.4