When set to TRUE, enables the search cache.
The search cache improves search performance by caching recent search engine queries.
Default is TRUE.
As a configuration variable:
If this variable is set to FALSE and used on the CGI line of a browser URL request doing a query, it forces the query to execute each time. This makes it possible to measure the speed of the query being executed and to verify the cache results (because a new search result is generated each time).