Add STRAIGHT_JOIN to ApiQueryLogEvents and LogPager to avoid planner oddness

[lhc/web/wiklou.git] / includes / api / ApiQueryLogEvents.php

diff --git a/includes/api/ApiQueryLogEvents.php b/includes/api/ApiQueryLogEvents.php
index 7798688..962d956 100644 (file)
--- a/includes/api/ApiQueryLogEvents.php
+++ b/includes/api/ApiQueryLogEvents.php
@@ -238,6 +238,14 @@ class ApiQueryLogEvents extends ApiQueryBase {
                        }
                }
 
+               // T220999: MySQL/MariaDB (10.1.37) can sometimes irrationally decide that querying `actor` before
+               // `logging` and filesorting is somehow better than querying $limit+1 rows from `logging`.
+               // Tell it not to reorder the query. But not when `letag` was used, as it seems as likely
+               // to be harmed as helped in that case.
+               if ( $params['tag'] === null ) {
+                       $this->addOption( 'STRAIGHT_JOIN' );
+               }
+
                $count = 0;
                $res = $this->select( __METHOD__ );
                $result = $this->getResult();