#73045 by jhenry and davemicc. Add an index to {file_revisions} for faster queries.

modules/system/system.install

@@ -243,7 +243,8 @@ function system_install() {
         vid int unsigned NOT NULL default 0,
         description varchar(255) NOT NULL default '',
         list tinyint unsigned NOT NULL default 0,
-        PRIMARY KEY (fid, vid)
+        PRIMARY KEY (fid, vid),
+        KEY (vid)
       ) /*!40100 DEFAULT CHARACTER SET UTF8 */ ");
 
       db_query("CREATE TABLE {filter_formats} (
@@ -674,6 +675,7 @@ function system_install() {
         list smallint_unsigned NOT NULL default 0,
         PRIMARY KEY (fid, vid)
       )");
+      db_query("CREATE INDEX file_revisions_vid_idx ON file_revisions(vid)");
 
       db_query("CREATE TABLE {filter_formats} (
         format serial,
@@ -3367,6 +3369,20 @@ function system_update_1011() {
   return $ret;
 }
 
+function system_update_1012() {
+  $ret = array();
+  switch ($GLOBALS['db_type']) {
+    case 'mysql':
+    case 'mysqli':
+      $ret[] = update_sql("ALTER TABLE {file_revisions} ADD INDEX(vid)");
+      break;
+    case 'pgsql':
+      $ret[] = update_sql('CREATE INDEX {file_revisions}_vid_idx ON {file_revisions}(vid)');
+      break;
+  }
+  return $ret;
+}
+
 /**
  * @} End of "defgroup updates-4.7-to-x.x"
  * The next series of updates should start at 2000.