}
$dbw = wfGetDB( DB_MASTER );
- $dbw->delete( 'user_properties', array( 'up_user' => $userId ), __METHOD__ );
- $dbw->insert( 'user_properties', $insert_rows, __METHOD__ );
+ $hasRows = $dbw->selectField( 'user_properties', '1',
+ array( 'up_user' => $userId ), __METHOD__ );
+
+ if ( $hasRows ) {
+ // Only do this delete if there is something there. A very large portion of
+ // calls to this function are for setting 'rememberpassword' for new accounts.
+ // Doing this delete for new accounts with no rows in the table rougly causes
+ // gap locks on [max user ID,+infinity) which causes high contention since many
+ // updates will pile up on each other since they are for higher (newer) user IDs.
+ $dbw->delete( 'user_properties', array( 'up_user' => $userId ), __METHOD__ );
+ }
+ $dbw->insert( 'user_properties', $insert_rows, __METHOD__, array( 'IGNORE' ) );
}
/**