Performance

SQL Server AlwaysOn availability groups and statistic issues on secondaries

I would like to share with you an interesting issue you may face while using SQL Server AlwaysOn availability groups and secondary read-only replicas. For those who use secondary read-only replicas as reporting servers, keep reading this blog post because(…)

Partitioning – When data movement is not performed as expected

This blog is about an interesting partitioning story and curious data movements during merge operation. I was at my one of my customer uses intensively partitioning for various reasons including archiving and manageability. A couple of days(…)

When an index seek operator is not always your friend

Did you ever consider an index seek as an issue? . Well, let’s talk about a story with one of my customers where the context is pretty simple: a particular query that is out of the range of the application’s(…)

SQL Server AlwaysOn: troubleshooting improvements with new service packs

As promised in my latest blog, I will talk about improvements in the detection of the availability group replication latency. As a reminder, replication latency between high(…)

SQL Server 2016 AlwaysOn: Direct seeding and performance considerations

This blog post follows the previous one about new direct seeding feature shipped with SQL Server 2016. As a reminder, I had some doubts about using direct seeding with large databases because log stream is not(…)

A look at PostgreSQL 9.6 – The wait interface

For a long time there was no real wait interface in PostgreSQL core. Now, with the upcoming 9.6, pg_stat_activity was extended to provide more meaningful information for what a session is currently waiting on.

SQL Server 2016: new database-scoped configuration parameters part 2

In this blog post, let’s continue with other database-scoped options shipped with the SQL Server 2016 RC0. We will first begin with the first one and my preferred option: setting the MAXDOP value for(…)

SQL Server 2016 : nonclustered columnstore index and aggregate pushdown

Did you miss aggregate pushdown capability shipped with columnstore index? Well, I remember the first time I heard about it is was when I read the very interesting blog post of Niko Neugebauer here with a(…)

Sudden drop of the page life expectandy but don’t panic yet!

A couple of weeks ago, I had an interesting discussion with one of my customer about the page life expectancy (aka PLE). He asked me if monitoring the metric value is a best practice because he often noticed a big(…)

Changing an existing partition configuration … Well, not so easy!

This time let’s talk about an interesting customer scenario where table partitioning was implemented on a table with 100 GB of data on SQL Server 2014. Partitioning in this context aimed to save disk space  (archive data were compressed) , help(…)