EF 4.1 Sql CE性能问题

Question

I know, i'm on question mode tonight,

I'm in the middle of building a desktop application. Luckily for me a choose a open architecture because i ran into the following problem:

My application allows users to add operations. In my tests, i only added small (test) operations which are easily manageble. Each operation is added to a datastore which currently is a SQL CE 4.0 database (accessed using EF 4.1 code first which is great).

Now i tested the application using a common operation which is bigger (approximatly 4000 rows in the Database). Rather then taking a few seconds, it actually takes a few minutes for insert! In the big table, there is only 1 foreign key and ofcourse the primary key, but it seems 4000 rows are just to much for it.

All rows are inserted in 1 batch and the real performance lack is on the SaveChanges command.

I've red about using manual queries (havent tested it) but this is no preferred option since transactions arent supported and it must be an isolated operation.

So, do i need a new strategy here? On SQL Server 2008 you can do a bulk insert but appareantly that is also not supported by Sql Server CE.

What clientside solutions are as flexible as SQL Server CE and lightweight? (eg Ofcourse i dont want the user to install SQL Server, nor use some native components).

I can use serialization in some forms but that feels like reinventing the wheel and is alot of work (upgrading, integrity, multithreaded access etc).

Thanks in advance!

Answer 1

The question is how slow is normally insert operation on SQL CE? The problem with EF is that it doesn't request one batch to insert 4.000 records but it inserts records one by one. Current EF version has no support for command batching so you are executing 4.000 inserts in the sequence. This is a problem on a big SQL Server as well but it is usually faster. I was able to insert around 50.000 - 100.000 more complex records to SQL Server within six minutes on slower desktop and within three minutes on the server.

Answer 2

http://msdn.microsoft.com/en-us/magazine/gg490349.aspx

not specifically the anwser to your problem but these techniques will def help you troubleshoot your queries.

Answer 3

Both answers were helpfull but didnt provide a solution.

I found this: http://sqlcebulkcopy.codeplex.com/ which provides a SqlCeBulkCopy class which works and performed the insert within 2 seconds!. I'm now working on intergrating it in my current repository and unitofwork model. As soon as i found the best solution i will post it here.

Soon to be followed...