After upgrading our wiki to MW 1.34, we noticed updated pages dropping from the index.
Using recent versions of MW, the sql_query parameter should be changed to:
sql_query = SELECT page_id, page_title, page_namespace, page_is_redirect, old_id, old_text FROM page, slots, content, text WHERE slots.slot_revision_id=page.page_latest AND content.content_id=slots.slot_content_id AND text.old_id=REPLACE(content.content_address, 'tt:', '')
Initially posted to: https://www.mediawiki.org/wiki/Topic:Vkmeh7v01ai6p3ka