Hi, when we migrated our wikis to actor, we noticed they were failing to rebuild there search index when we ran "rebuildtextindex.php", it would cause a OOM. So we got the sql query which was:
```
SELECT rev_id,rev_page,rev_text_id,rev_timestamp,rev_minor_edit,rev_deleted,rev_len,rev_parent_id,rev_sha1,rev_comment AS `rev_comment_text`,NULL AS `rev_comment_data`,NULL AS `rev_comment_cid`,actor_rev_user.actor_user AS `rev_user`,actor_rev_user.actor_name AS `rev_user_text`,temp_rev_user.revactor_actor AS `rev_actor`,rev_content_format,rev_content_model,page_namespace,page_title,page_id,page_latest,page_is_redirect,page_len,old_text,old_flags FROM `revision`,`revision_actor_temp` `temp_rev_user`,`actor` `actor_rev_user`,`page`,`text` WHERE (page_id BETWEEN 0 AND 499) AND (page_latest = rev_id) AND (rev_text_id = old_id);
```
We also ran that on the db server which went very crazy. Possibly due to it having "NULL AS"?
I've linked it to actor because as soon as i change the constant back to "MIGRATION_OLD", i can run rebuildtextindex.php.