Help:$smwgFulltextDeferredUpdate

is a configuration parameter that sets the number of expected updates for the index table of the full-text search thus allowing to throttle it. It was introduced in Semantic MediaWiki 2.5.0.CiteRef::gh:smw:1481

It can be of advantage to postpone the index update using a deferred job execution to decouple changes to the storage back-end and the full-text index table. In case this configuration setting and the  configuration parameter are both set to " ", i.e. enabled then the updater will try to open a new process for posting instructions to execute the "SearchTableUpdateJob" immediately otherwise it will be added to the job queue and MediaWiki's "runJobs.php" maintenance script is required to perform it.

If a user wants to avoid the job queue being used for performing updates via "SearchTableUpdateJob" then this setting can be disabled by changing the setting to " ".