If you haven't noticed, SQL Server Release Services dropped an updated CU6 for SQL Server 2014 SP1 this week. This replaces a previous CU6 that had a NOLOCK bug in it, and the old KB article (and patch) have been deprecated. You can install the new CU#6 on top of the old one, and you should. The old patch could cause you some issues, so if you've applied CU#6 previously (build 12.0.4449), go download the updated patch, test it, and apply it to your instances.

However, there's a couple issues with the process here. First, re-releasing a patch under the same name (with a different build) is confusing. I am sure there are going to be plenty of people, especially accidental DBAs, that think they've applied CU 6, and they don't realize there has been a change. There will be others that apply the patch from an old download that's shared on their file system. I'd much rather have fixed patches released as a new CU. What does it matter if CU #7 is released now instead of in a few months? There's no limit I'm aware of for the number of CUs allowed for a particular version, so let's just increment numbers.

The second issue, for me, is that this eats up time. Releasing quickly is one of the problems with an agile approach, where you update software quite often. There isn't necessarily enough time to completely test the the fixes, and as comprehensive as the Microsoft testing suite is, there will be things that are missed. I certainly think Microsoft deserves kudos for finding the issue and releasing a fix so quickly. However, will this patch be distributed as quickly as the original CU #6?

If you are used to applying these CUs, are you going to notice there is a new version of this CU to apply? The blog entry title doesn't note this is re-released. If you look for the latest patches and see CU #6, will you realize this fix has been updated? If you know there's a new patch, will you have time to re-test the update and schedule another release? I know from experience in a large organization, re-applying Service Pack 3a for SQL Server 2000 was a chore, with limited time to re-deploy a patch among all the other work we had scheduled.

One thing I've noticed is that more and more companies are depending on their databases more often, demanding higher uptime and fewer maintenance windows. The more patches we have, the more troublesome it can be to get permission to apply these patches, especially across a large server farm. Microsoft is building a better engineering process, that allowed for more comprehensive (internal) testing and quicker releases, but this process doesn't necessarily prevent all mistakes. Those mistakes are not only bad press, but they reduce confidence in the entire process.

I do think these CUs will start to take the place of Service Packs at some point, though I think the pace will become problematic for many organizations, especially those running third party software. I'm guessing that at some point, a good portion of the SQL Server community will start treating these patches like upgrades, and not applying every one. Many people will end up applying only every fourth or fifth patch, much like people seem to be upgrading many instances every 6 or 8 years.