From: Byron Jones <glob@mozilla.com>
Date: Mon, 5 May 2014 07:15:37 +0000 (+0800)
Subject: Bug 999331: searching attachment data is very slow due to an unbounded
X-Git-Tag: bugzilla-4.4.5~17
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cbc08e72fa2cb0bd711ea3c82d9e3530ae88184b;p=thirdparty%2Fbugzilla.git

Bug 999331: searching attachment data is very slow due to an unbounded
select
r=LpSolit, a=glob
---

diff --git a/Bugzilla/Search.pm b/Bugzilla/Search.pm
index f900b34740..7df9d04c1e 100644
--- a/Bugzilla/Search.pm
+++ b/Bugzilla/Search.pm
@@ -1968,6 +1968,13 @@ sub _quote_unless_numeric {
 
 sub build_subselect {
     my ($outer, $inner, $table, $cond, $negate) = @_;
+    if ($table =~ /\battach_data\b/) {
+        # It takes a long time to scan the whole attach_data table
+        # unconditionally, so we return the subselect and let the DB optimizer
+        # restrict the search based on other search criteria.
+        my $not = $negate ? "NOT" : "";
+        return "$outer $not IN (SELECT DISTINCT $inner FROM $table WHERE $cond)";
+    }
     # Execute subselects immediately to avoid dependent subqueries, which are
     # large performance hits on MySql
     my $q = "SELECT DISTINCT $inner FROM $table WHERE $cond";