The current SqlChangeDispatchCoordinator wouldn't work on non-MySQL databases (with CAST in its syntax T207226: Wikibase does not support Postgresql (and does not even mention it requires mysql)) nor in a wiki that has a table prefix. This really should go away:
$where = [ '( chd_touched < ' . $dbr->addQuotes( $freshDispatchTime ) . // and wasn't touched too recently or // or it's lagging by more than batchSize ' OR ( ' . (int)$maxId . ' - CAST(chd_seen AS SIGNED) ) > ' . (int)$this->batchSize . ') ' , 'chd_seen < ' . (int)$maxId, // and not fully up to date. 'chd_disabled = 0' // and not disabled ];
This is a blocker of enabling Postgres as a voting CI job.