AddDbContext or AddDbContextPool
For Asp.net Core apps, which one do we have to use? AddDbContext
or AddDbContextPool
? According to EF Core documentation, AddDbContextPool
provides high performance but the default Asp.net Core project templates use AddDbContext
.
The answer is here (under "DbContext pooling"): https://docs.microsoft.com/en-us/ef/core/what-is-new/ef-core-2.0#dbcontext-pooling
DbContext
is not thread-safe. So you cannot reuse the same DbContext
object for multiple queries at the same time (weird things happen). The usual solution for this has been to just create a new DbContext
object each time you need one. That's what AddDbContext
does.
However, there is nothing wrong with reusing a DbContext
object after a previous query has already completed. That's what AddDbContextPool
does. It keeps multiple DbContext
objects alive and gives you an unused one rather than creating a new one each time.
Which one you use is up to you. Both will work. Pooling has some performance gains. However the documentation warns that if you use any private properties in your DbContext
class that should not be shared between queries, then you should not use it. I imagine that's pretty rare though, so pooling should be appropriate in most cases.