Currently, DELETE on deferred connection are executed in uncatalogObject grouped activity. If Mroonga index is broken or locked, uncatalogObject activity will be blocked.
And if Mroonga index is broken or locked AND any activity is spawned by uncatalogObject, activity table will be locked and whole activity processing will be blocked until uncatalogObject finishes.
To avoid such situation, DELETE on deferred connection are also executed in another activity, like we already did for indexation in c39b8e0a.
To make introducing more full text tables easily, now new dedicated search key, sql_deferred_catalog_object_list and sql_deferred_uncatalog_object are introduced. Note that sql_deferred_uncatalog_object SQL should have multiple keyword in uid DTML.