Entity Framework 4 and caching of query results

Question

Say I have a table or 2 that contains data that will never or rarely change, is there any point of trying to cache those data? Or will the EF context cache that data for me when I load them the first time? I was thinking of loading all the data from those tables and use a static list or something to keep that data in memory and query the in memory data instead of the tables whenever I need the data within the same context. Those tables I speak of contains typically a few hundred rows of data.

Answer 1

The EF context will cache "per instance". That is, each instance of the DbContext keeps it's own independent cache of objects. You can store the resulting list of objects in a static list and query it all you like without returning to the database. To be safe, make sure you abandon the DbContext after you execute the query.

var dbContext = new YourDbContext(); StaticData.CachedListOfThings = dbContext.ListOfThings.ToList(); 

You can later use LINQ to query the static list.

var widgets = StaticData.CachedListOfThing.Where(thing => thing.Widget == "Foo"); 

The query executes the in-memory collection, not the database.