Question

Does anyone have an idea as to why SQL Azure does not support with nolock SQL statements. Does Microsoft has any plans of supporting this in the future?

Answer 1

I tried running a nolock query on SQL azure and it works. That got me thinking that the statement is ignored because technically you don’t have the option to set the database option (READ_COMMITTED_SNAPSHOT and ALLOW_SNAPSHOT_ISOLATION). I’m guessing this is the reason but I’ll try and do some more digging.

Note: this is an Azure limitation.

You can find more information here:

Both the READ_COMMITTED_SNAPSHOT and ALLOW_SNAPSHOT_ISOLATION database
options are set to ON in SQL Azure Database. Because SET
in the ALTER DATABASE Transact-SQL statement is not
supported, these database options cannot be changed. For more
information on row versioning-based isolation levels, see
Understanding Row Versioning-Based Isolation Levels.

Update: after a quick discussion with two über SQL experts, the solution appears to be to use a query like:

set transaction isolation level READ UNCOMMITTED
select * from myTestTable

So for every batch, you need to specify the isolation level.