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Month: December 2017

Locks And Partitioning

Published 2017-12-01 by Kevin Feasel

Erik Darling looks at the confusing mess that is SQL Server partitioning:

In the Chicago perf class last month, we had a student ask if partition level locks would ever escalate to a table level lock. I wrote up a demo and everything, but we ran out of time before I could go over it.

Not that I’m complaining — partitioning, and especially partition level locking, can be pretty confusing to look at.

If you really wanna learn about it, you should talk to Kendra — after all, this post is where I usually send folks who don’t believe me about the performance stuff.

Click through for that demo and explanation.

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Getting Started With Always Encrypted

Published 2017-12-01 by Kevin Feasel

Monica Rathbun kicks off a series on Always Encrypted:

There are two possibilities Deterministic and Randomized.

MSDN defines Deterministic encryption as always generates the same encrypted value for any given plain text value. Which means that if you have a birthdate of 01/03/1958 it will always be encrypted with the same value each time such as ABCACBACB. This allows you to index it, use it in WHERE clauses, GROUP BY and JOINS.

Randomized encryption per MSDN- uses a method that encrypts data in a less predictable manner. This makes Randomized encryption more secure, because using the example above each encrypted value of 01/03/1958 will be different. It could be ABCACBACB, BBBCCAA, or CCCAAABBB. All three encrypted values are subsequently decrypted to the same value. Since the encrypted value is random you cannot perform search operations etc. as you can with Deterministic.

Part 1 is about building the certificates and keys needed to encrypt data.

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Upgrading That Expired Evaluation Copy Of SQL Server

Published 2017-12-01 by Kevin Feasel

Cody Konior finds a way to extricate the poor souls who need to upgrade expired evaluation copies of SQL Server from their mess:

Common advice here is to set the clock backwards. My problem with that is that you’re probably doing this on an unsupported unknown black-box flaming garbage can of a system set up by someone who wasn’t meant to do it – because otherwise they wouldn’t be using the evaluation edition. So what are the repercussions of setting the clock backwards? Perhaps their application spawning silently in the background and trashing this or other databases with bad date information? Perhaps you’ll lose your RDP connection and then be unable to connect back in because of the SSPI error generated by a clock mismatch?

No thanks. Instead you need to do some detective work.

Read the whole thing.

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Using Pester For Configuration Checks

Published 2017-12-01 by Kevin Feasel

Andrew Pruski shows how to use Pester to audit SQL Server configuration settings:

One Pester test running!

What I like about this is that it can be easily dropped into a job scheduler (e.g.- Jenkins) and then you’ve got a way to routinely check (and correct) all the configuration settings of the SQL instances that you monitor.

Pester would not have been my first thought for configuration checking, but it does serve as another useful option.

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