From 5002bf9cc1c9c25f0b7d180ac8400640513df913 Mon Sep 17 00:00:00 2001 From: Robin Appelman Date: Mon, 18 Oct 2021 18:05:48 +0200 Subject: [PATCH] tell mysql to ignore the sort index for search queries mysql really likes to pick an index for sorting if it can't fully satisfy the where filter with an index, since search queries pretty much never are fully filtered by index mysql often picks an index for sorting instead of the *much* more useful index for filtering. To bypass this, we tell mysql explicitly not to use the mtime (the default order field) index, so it will instead pick an index that is actually useful. Signed-off-by: Robin Appelman --- 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 ae707fb5b54..99be91f5d6b 100644 --- a/lib/private/Files/Cache/Cache.php +++ b/lib/private/Files/Cache/Cache.php @@ -840,7 +840,13 @@ class Cache implements ICache { protected function buildSearchQuery(ISearchQuery $searchQuery): IQueryBuilder { $builder = $this->getQueryBuilder(); - $query = $builder->selectFileCache('file'); + // mysql really likes to pick an index for sorting if it can't fully satisfy the where + // filter with an index, since search queries pretty much never are fully filtered by index + // mysql often picks an index for sorting instead of the *much* more useful index for filtering. + // + // To bypass this, we tell mysql explicitly not to use the mtime (the default order field) index, + // so it will instead pick an index that is actually useful. + $query = $builder->selectFileCache('file', 'ignore index for order by (fs_mtime)'); $query->whereStorageId();