SELECT *
FROM Posts
WHERE Tags IN ('SQL Server Internals')

May
10
2016

Successful Anti-Patterns, Key Lookup VS RID Lookup

When it comes to technical subjects like databases, we must always look for proven solutions and best practices, which usually take us from A to B in the most efficient way. Usually. But what happens…

Continue Reading »

Apr
15
2016

Back To Basics, Lock Escalation in SQL Server

Today at work we’ve had a very common request, no big deal, just a couple of UPDATE which affect tens of thousands of rows in a couple of tables independently. I can say I’ve been there, done that…

Continue Reading »

Mar
14
2016

The Mysterious Case of the Missing Default Value

*First published @ www.SQLServerCentral.com (2015/12/01) Once upon a time, there was a DBA… yeah right! As probably like many SQL DBA’s, little by little I’m getting more curious about how SQL Server works internally. To…

Continue Reading »

Mar
3
2016

Fast with values slow with variables

The other day I saw a thread on linkedin groups that was titled ‘Using Parameters in a Query is Killing Performance’, where the author…

Continue Reading »

Feb
29
2016

Clustered index row order

One of the basic (and well used during interviews) questions about SQL Server internals is how you call a table without a clustered index, and that in SQL Server is called a HEAP….

Continue Reading »

Feb
15
2016

Row compression, a bit of internals

Compression in SQL Server has been around for a while now, to be precise since SQL Server 2008, and comes in two different (complementary) flavors, ROW and PAGE compression. Unfortunately it’s only available in the Enterprise Edition (and Developer…

Continue Reading »

Oct
28
2015

Daylight Savings end affects not only you, but your SQL Server too

The last weekend of October is a common date for the daylight savings (or summer time) to get to its end in the north hemisphere. According to Wikipedia: Daylight saving time (DST) or…

Continue Reading »

Oct
10
2015

Steve Stedman’s DBCC Challenge, Week-7 Winning Solution

*First published @ Steve Stedman’s blog (2015/06/07) The seventh week of ten in the Database Corruption Challenge went well. There were a few new participants, and many of those who have competed week over week. The first to submit a correct answer this week was Raul…

Continue Reading »

Oct
10
2015

Steve Stedman’s DBCC Challenge, Week-6 Winning Solution

*First published @ Steve Stedman’s blog (2015/05/27) If you are looking for more info on the corrupt database with Week 6 of the Database Corruption Challenge, you can take a look at the original post. Week 6 was won by Raul Gonzalez who submitted his…

Continue Reading »

Oct
10
2015

Steve Stedman’s DBCC Challenge, Week-4 Second Alternate Solution

*First published @ Steve Stedman’s blog (2015/05/06) The following is a solution to Corruption Challenge #4 that uses DBCC WritePage to fix the corruption.  Before proceeding, be sure to read this warning. WARNING: DBCC WritePage is a dangerous command, that should never be used…

Continue Reading »