ApiQueryUserContribs: Only use 'contributions' replica if querying by user ID

When querying by user name or actor ID, the partitioning on the
'contributions' replicas makes things worse rather than better.

Bug: T216656
Change-Id: Ib4caf19d8fad64c527dee99667e425fd3e4b1a16

diff --git a/includes/api/ApiQueryUserContribs.php b/includes/api/ApiQueryUserContribs.php
index 6082617..ae1be0d 100644 (file)
--- a/includes/api/ApiQueryUserContribs.php
+++ b/includes/api/ApiQueryUserContribs.php
@@ -61,14 +61,11 @@ class ApiQueryUserContribs extends ApiQueryBase {
                $this->fld_patrolled = isset( $prop['patrolled'] );
                $this->fld_tags = isset( $prop['tags'] );
 
-               // Most of this code will use the 'contributions' group DB, which can map to replica DBs
+               // The main query may use the 'contributions' group DB, which can map to replica DBs
                // with extra user based indexes or partioning by user. The additional metadata
                // queries should use a regular replica DB since the lookup pattern is not all by user.
                $dbSecondary = $this->getDB(); // any random replica DB
 
-               // TODO: if the query is going only against the revision table, should this be done?
-               $this->selectNamedDB( 'contributions', DB_REPLICA, 'contributions' );
-
                $sort = ( $this->params['dir'] == 'newer' ? '' : ' DESC' );
                $op = ( $this->params['dir'] == 'older' ? '<' : '>' );
 
@@ -269,6 +266,13 @@ class ApiQueryUserContribs extends ApiQueryBase {
                        $this->orderBy = 'actor';
                }
 
+               // Use the 'contributions' replica, but only if we're querying by user ID (T216656).
+               if ( $this->orderBy === 'id' &&
+                       !( $wgActorTableSchemaMigrationStage & SCHEMA_COMPAT_READ_NEW )
+               ) {
+                       $this->selectNamedDB( 'contributions', DB_REPLICA, 'contributions' );
+               }
+
                $count = 0;
                $limit = $this->params['limit'];
                $userIter->rewind();