Hello community.

We have db with "read commited snapshot" set to ON.

We run query:

SET TRANSACTION ISOLATION LEVEL READ COMMITTED
BEGIN TRANSACTION
select * from Account where Id = 14
WAITFOR DELAY '00:00:15' 
COMMIT

While this transaction waiting, other transactions can read this data, so if we run query, we'll immediately get the result.

SET TRANSACTION ISOLATION LEVEL READ COMMITTED
BEGIN TRANSACTION
select * from Account where Id = 14
COMMIT

But when we trying to use DO, we get lock on data.

We run this code twice with 2-3 second difference.

using (var session = DomainBuilder.Domain.OpenSession())
{
    using (var trans = session.OpenTransaction(IsolationLevel.ReadCommitted))
    {

    var acc = session.Query.All<_Account>()
        .FirstOrDefault(a => a.Id == 14);

    Debug.Write("selected: " + acc.Name);

    Thread.Sleep(new TimeSpan(0, 0, 10));

    Debug.Write("stop waiting: " + acc.Name);

    trans.Complete();
}

}

We expected:

selected: John Smith
selected: John Smith
stop waiting: John Smith
stop waiting: John Smith

But result is:

selected: John Smith
stop waiting: John Smith
selected: John Smith
stop waiting: John Smith

Seems that first query locks Account with id=14 from reading by another transactions.

This happens even we use "read uncommited" or set "read commited snapshot" to OFF.

Where is our mistake?

Thanks in advance.