LINQ LongCount is not supported by cosmosdb client

[FluentGuru]

container.GetItemLinqQueryable().Where(predicate).LongCount() throws a NotSupportedException

[j82w]

Hi @FluentGuru ,

There is currently a PR to add support for CountAsync which is what you should use.

[FluentGuru]

@j82w understood

[thomaslevesque]

I think the exception hit by @FluentGuru was because he didn't set allowSynchronousQueryExecution to true (argument to GetItemLinqQueryable), so synchronous operations are rejected.

But if you do set allowSynchronousQueryExecution to true, you get this instead:

Microsoft.Azure.Cosmos.Linq.DocumentQueryException: 'Method 'LongCount' is not supported.'

Is there a reason why it's not supported? I mean, Int32 should be enough for most scenarios, but when there are more than 2^31 documents, what happens?

[FluentGuru]

@thomaslevesque I did had the flag set to true and got that exact error you are getting.