Can you show the query? Just because it runs doesn't mean it's correct. :-) For example this is not legal, but it works:
SELECT CONVERT(SMALLDATETIME, modify_date) AS modify_date
FROM sys.objects AS o
ORDER BY o.modify_date;
Technically, it should be as follows, since o.modify_date is not in the SELECT list:
SELECT CONVERT(SMALLDATETIME, modify_date) AS modify_date
FROM sys.objects AS o
ORDER BY modify_date;
In this Connect bug, it was stated that this rule would be removed from the Upgrade Advisor. I suspect that one of the following (or both) happened:
- They forgot to remove the rule as they said they would
- They had other complications which prevented the above syntax from being blocked by the parser
That all said, there are some breaking changes the upgrade advisor will never catch. For example, this will work on 2005, 2008 and 2008 R2:
CREATE TABLE #foo(id INT);
IF OBJECT_ID('tempdb..#foo') > 0
BEGIN
DROP TABLE #foo;
END
GO
CREATE TABLE #foo(id INT);
This will break in SQL Server 2012, however, since #temp tables now get a negative object_id. The proper way to test is:
IF OBJECT_ID('tempdb..#foo') IS NOT NULL
I go over a few other issues in this blog post. A couple of other breaking changes:
If you use any of the memory-related DMVs there has been a major overhaul to some of the columns:
Again, most of these are not caught by the upgrade advisor, so running that tool and not doing any thorough testing could really put you in a bad spot.
And I agree with Eric's answer - you should try to track deprecated events. For completeness, here are three approaches:
Have a look at the following link:
ALTER DATABASE Compatibility Level
Scroll down and you will see the section "Differences Between Lower Compatibility Levels and Level 110" and identify if any of these items will affect you or not. If not, then just change the level to 110.
Best Answer
There's several parts to this question:
Do I need to set the database to single user mode to change the compatibility level? No.
Will changing the compat mode from 90 to 110 break log shipping? No.
Can I change a log shipped database to single user mode? Yes, but don't do that unless you have to. Sometimes, you might not end up being the single user (like if someone else grabs the connection from you, like if your SSMS crashes after you set it to single user mode.)