Manual:$wgQueryCacheLimit

Performance hacks and limits: $wgQueryCacheLimit
Number of rows to cache in 'querycache' table when miser mode is on.
Introduced in version:	1.9.0 (r18162)
Removed in version:	still in use
Allowed values:	(integer)
Default value:	1000
Other settings: Alphabetical | By function

Details

Number of rows to cache in 'querycache' table when miser mode is on.

This variable is related to QueryPage, a cache associated with SpecialPages.