From a4e120c2034bc1739d7428245660670b09aa7a75 Mon Sep 17 00:00:00 2001 From: Robin Appelman Date: Fri, 22 Apr 2022 13:31:34 +0200 Subject: tell mysql to ignore the sort index for search queries Signed-off-by: Robin Appelman --- lib/private/Files/Cache/SearchBuilder.php | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'lib/private/Files/Cache') diff --git a/lib/private/Files/Cache/SearchBuilder.php b/lib/private/Files/Cache/SearchBuilder.php index 003d3ac15e7..c8c442bcb8c 100644 --- a/lib/private/Files/Cache/SearchBuilder.php +++ b/lib/private/Files/Cache/SearchBuilder.php @@ -232,6 +232,17 @@ class SearchBuilder { if ($field === 'fileid') { $field = 'file.fileid'; } + + // Mysql really likes to pick an index for sorting if it can't fully satisfy the where + // filter with an index, since search queries pretty much never are fully filtered by index + // mysql often picks an index for sorting instead of the much more useful index for filtering. + // + // By changing the order by to an expression, mysql isn't smart enough to see that it could still + // use the index, so it instead picks an index for the filtering + if ($field === 'mtime') { + $field = $query->func()->add($field, $query->createNamedParameter(0)); + } + $query->addOrderBy($field, $order->getDirection()); } } -- cgit v1.2.3