Manual:$wgDefaultExternalStore

LoadBalancer settings: $wgDefaultExternalStore
Default external store for new revisions.
Introduced in version:	1.6.0 (r12537)
Removed in version:	still in use
Allowed values:	string or false
Default value:	false

Other settings: Alphabetical | By Function

Details

The place to put new revisions, false to put them in the local text table. Part of a URL, e.g. DB://cluster1

Can be an array instead of a single string, to enable data distribution. Keys must be consecutive integers, starting at zero. Example:

$wgDefaultExternalStore = array( 'DB://cluster1', 'DB://cluster2' );