From 8d51e8eb724b8d13c23b74f26933aa3b5a6eaa49 Mon Sep 17 00:00:00 2001 From: Jens-Christian Fischer Date: Sat, 11 Apr 2015 18:06:21 +0200 Subject: don't update identical values The UPDATE oc_filecache statement blindly overwrites identical data. Databases like Postgres that create a new row on an update and mark the old one as dead will suffer from the previous behaviour, as millions of "new" rows are created in the database. This patch changes the WHERE clause to test for identical values and not updating if the values in the DB are identical to the ones being passed. --- lib/private/files/cache/cache.php | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/lib/private/files/cache/cache.php b/lib/private/files/cache/cache.php index e9ed987a6ff..7ea90d0e75e 100644 --- a/lib/private/files/cache/cache.php +++ b/lib/private/files/cache/cache.php @@ -285,10 +285,16 @@ class Cache { } list($queryParts, $params) = $this->buildParts($data); + + $params = array_merge($params, $params); $params[] = $id; - $sql = 'UPDATE `*PREFIX*filecache` SET ' . implode(' = ?, ', $queryParts) . '=? WHERE `fileid` = ?'; + // don't update if the data we try to set is the same as the one in the record + // some databases (Postgres) don't like superfluous updates + $sql = 'UPDATE `*PREFIX*filecache` SET ' . implode(' = ?, ', $queryParts) . '=? ' . + 'WHERE (' . implode(' <> ? OR ', $queryParts) . ' <> ? ) AND `fileid` = ? '; \OC_DB::executeAudited($sql, $params); + } /** -- cgit v1.2.3