To improve performance the Value History Service’s datastore makes use of an in-memory database page cache. This cache has two parameters that need to be configured in the VHS configuration file:
|
— |
Specifies the maximum size of the database page cache for the VHS datastore in megabytes. The default for this keyword is 1000 megabytes. |
|
|
— |
Specifies the minimum size of the database page cache for the VHS datastore in megabytes. The default for this parameter is 200 megabytes. |
The underlying database engine evaluates the availability of system memory resources before saving pages in the page cache. If memory is highly constrained, the cache will not grow even if the maximum setting has not been reached. See How ESE Works for more information.
The following info items are available in the VHS to report the two cache parameters, as well as the current cache utilization.
|
|
|