Here are the questions we get most often about SQL Server service packs and cumulative updates:
What’s the difference between a service pack, cumulative update, and a hotfix?
A hotfix fixes a single issue, and hasn’t been extensively tested.
A cumulative update is a rollup of several hotfixes, and has been tested as a group.
A service pack is a rollup of several cumulative updates, and in theory, has been tested even more than cumulative updates.
Which ones should I apply?
If you’re building a new SQL 2012-2014 server from scratch, apply the most recent service pack and cumulative update.
If you’re patching an older server (SQL 2005-2008R2), know that the patching frequency has pretty much stopped. Go ahead and apply the most recent service pack and cumulative update, and your patching work will be done for quite a while.
If you’re patching SQL 2012-2014, things get a little trickier. We recommend applying the most recent service pack and cumulative update in your development, QA, and staging environments first. Let the updates live there for a couple of weeks and make sure there’s no problems before patching your disaster recovery and production environments.
What risks should I be aware of when patching?
Since 2012, there have been several high-profile incidents around patch quality.
- SQL Server 2014 SP1 was pulled within a day of release
- SQL Server 2012 SP1 caused some servers to go to 100% CPU
- SQL Server 2012 SP1 introduced a data corruption bug
- 2012 SP2 CU3 and 2014 CU5 caused some Availability Groups to stop replicating
You can’t simply stop patching, though, because these cumulative updates fix serious bugs that can cause downtime or data loss. Kendra Little explains the tough decision process about whether to patch or not.
Why do you list older service packs and updates here?
You might be building a server to add into an existing cluster, and you want to make its patch level match the rest of the cluster nodes. Or maybe your vendor only supports a certain SP/CU combination. Or maybe you like collecting antiques. Look, we’re not here to judge.
How are support end dates determined?
Microsoft has three phases of support. Mainstream support is part of Software Assurance and includes feature updates in SPs/CUs as well as security fixes. Extended Support and Premium Assurance cost extra:
We only list the end date for Extended Support.
Who runs this site?
The fine folks at Brent Ozar Unlimited, a boutique consulting shop that focuses on making SQL Server faster and more reliable.
We do a 3-day SQL Critical Care® that finds the root cause of your SQL Server pains, then trains you on how to get permanent pain relief.
We also offer in-person training classes and training videos online.