Manual:$wgDisableTextSearch

Search: $wgDisableTextSearch
Disable full-text search.
Introduced in version:pre 1.1.0
Removed in version:still in use
Allowed values:(boolean)
Default value:false

Details edit

Disables full text search.

See also Manual:$wgSearchForwardUrl to forward to a different search page. If search is disabled, and no forward url specified, a search form can be configured with MediaWiki:Googlesearch.