How to cap memory usage by Extensible Storage Engine (JetBlue)?

Question

I have an app that every so often hits a ESE database quite hard and then stops for a long time. After hitting the database memory usage goes way up (over 150MB) and stays high. I'm assuming ESE has lots of cached data.

Is there a way to cap the memory usage by ESE? I'm happy to suffer any perf hit

the only way I've seen to drop the memory usage is to close the DB

Answer 1

You can control the database cache size by setting the database cache size system parameter (JET_paramCacheSize). That number can be changed on-the-fly.

You might not need to set it though: by default ESENT will manage its cache size automatically by looking at available system memory, system paging and database I/O load. If you have hundreds of MB of free memory then ESENT won't see any reason to reduce the cache size. On the other hand. if you start using the memory on your system you should find that ESENT will automatically reduce the size of the database cache in your application. You can set the limits for automatic cache sizing with the JET_paramCacheSizeMin and JET_paramCacheSizeMax parameters.

Documentation link for the sytem parameters: http://msdn.microsoft.com/en-us/library/ms683044.aspx