Matthew McGiffen DBA

Rowcount estimates when there are no Statistics

• by Matthew McGiffen

• Matthew McGiffen DBA

When you don't have statistics, what does SQL use to calculate the estimated number of rows?

2021-02-04 (first published: 2021-01-26)

278 reads

When do Statistics get updated?

• by Matthew McGiffen

• Matthew McGiffen DBA

Statistics objects are important for allowing the SQL Server Optimizer to make good estimates and form efficient execution plans. Related to that it's useful for us to understand when...

2021-01-25 (first published: 2021-01-18)

471 reads

How does Query Store capture cross database queries?

• by Matthew McGiffen

• Matthew McGiffen DBA

Query Store is a configuration that is enabled per database, and the plans and stats for queries executed in that database are stored in the database itself. So what...

2021-01-18 (first published: 2021-01-11)

446 reads

Identify the (Top 20) most expensive queries across your SQL Server using Query Store

• by Matthew McGiffen

• Matthew McGiffen DBA

Script to identify the most expensive queries on your database server using the Query Store DMVs. This allows you to look at data from a specific time frame, as...

2021-01-11 (first published: 2021-01-04)

546 reads

SQL Puzzle – Eight Queens on a Chess board

• by Matthew McGiffen

• Matthew McGiffen DBA

Here's a SQL Puzzle for the festive period. 2020 has been a year of many things but amongst it all, it has been the year of chess. The combined...

2020-12-24 (first published: 2020-12-15)

451 reads

Introduction to SQL Server Query Store

• by Matthew McGiffen

• Matthew McGiffen DBA

Introduced with SQL 2016, Query Store was, probably without doubt, the most anticipated and talked out new feature. In this post we'll just take a brief look at it,...

2020-12-21 (first published: 2020-12-14)

882 reads

TDE in Standard Edition on SQL 2019

• by Matthew McGiffen

• Matthew McGiffen DBA

Recently Microsoft quietly let us know that TDE (Transparent Data Encryption) will be available in the Standard Edition of SQL Server 2019. If you don’t follow SQL topics on...

2019-11-12 (first published: 2019-11-05)

6,238 reads

Why Does Everyone Have More Friends Than You?

• by Matthew McGiffen

• Matthew McGiffen DBA

No, the answer isn’t because you’re a DBA. This isn’t a technical post about databases, but rather a discussion of a statistical paradox that I read about recently. Statistics...

2019-10-01

29 reads

Instantaneous Transaction Rollback with SQL 2019

• by Matthew McGiffen

• Matthew McGiffen DBA

If you’ve read about the Accelerated Database Recovery feature in SQL Server 2019 you could be forgiven for thinking it’s just about speeding up database recovery time in case...

2019-10-09 (first published: 2019-09-25)

869 reads

Check Query Progress with Live Query Stats

• by Matthew McGiffen

• Matthew McGiffen DBA

This is something I touched on back in 2017 a little after the Live Query Statistics feature was introduced with SQL 2016, but I was using the functionality this...

2019-09-26 (first published: 2019-09-18)

747 reads