Blogs

What’s it like to be a Database Administrator for managed databases in Azure? Sometimes it’s a painful guessing game when a routine, core operation– restoring a database – fails with a most unhelpful error.

In this case, if the restore is run via PowerShell, following Microsoft guidance, the error message is:

Restore-AzSqlInstanceDatabase: Long running operation failed with status ‘Failed’. Additional Info: An unexpected error occured while processing the request. [sic]

Somehow the misspelling of ‘occurred’ stings a bit more. Did anyone review the PR for this code?

Erik Darling and Kendra Little Rate SQL Server Perf Tuning Techniques

By Kendra Little in SQL Server

May 20, 2024

Erik Darling joins Kendra Little to rate different SQL Server Performance Tuning Techniques in episode 81 of the Dear SQL DBA podcast. We share our opinions of… (deep breath) Recompile hints, Query Store hints and plan forcing, CTEs, Resource Governor, the legacy cardinality estimator, Table Variables, Automatic Plan Correction, Batch Mode, index rebuilds, Hekaton, NOLOCK, page compression, partitioning, filtered indexes, columnstore, join hints, PSPO, indexed hints, indexed views, optimize for unknown, RCSI, adding more memory, restarting the damn thing, scalar UDFs, and Persisted Memory Grant Feedback.

Finally, A SQL Server Monitoring System that Leverages Query Store

By Kendra Little in SQL Server, Azure SQL

May 15, 2024

I’ve spent a bit of time with Microsoft’s new database watcher tool for Azure SQL recently. There are a lot of things I like about database watcher– which is currently in preview and which refuses to Capitalize Its Name– but it does one big thing that I really, really like: it collects data from Query Store. You can access that Query Store data from built-in database watcher dashboards, query it using KQL, or (something something) in Microsoft Fabric if you’ve got money to burn on your monitoring data.

Learn Perf Tuning in 2 Days at PASS Summit 2024 with Erik Darling and Kendra Little

By Kendra Little in PASS Summit, Training

May 1, 2024

I’m teaming up with Erik Darling to teach you SQL Server Performance Tuning in two days at the PASS Data Community Summit in Seattle.

Erik and I are co-teaching both days of training to give you a strong strategic background on the internals you need to know, along with critical tactical performance tuning techniques. Join us to level up your perf tuning skills!

Register Here →

Query Store Size Based Cleanup Causes Performance Problems - How to Avoid It

By Kendra Little in SQL Server

April 23, 2024

I’ve got a backlog of learnings from stress-testing to blog, so if you like this post there’s more to come. I’m a huge fan of SQL Server’s Query Store feature. Query Store collects query execution plans and aggregate query performance metrics, including wait stats. Having Query Store enabled makes troubleshooting performance issues such as bad parameter sniffing, much, much easier. Because Query Store is integrated into SQL Server itself, it also can catch query plans in a lightweight way that an external monitoring system will often miss.

Top 5 Toxic Flavors of Tech Execs

By Kendra Little in Tech

April 11, 2024

I’ve been an employee at small, medium, and large companies, and I’ve also been a short-term consultant working with a new company in any given week. I’ve worked with hundreds of tech companies remotely and have visited companies onsite on multiple continents.

Air-dropping into company cultures to work through problems with teams and present recommendations to their leadership reveals common anti-patterns in leadership – plus some patterns that make teams raving fans of their management.

Here’s the top 5 Toxic Flavors of Tech Execs I’ve encountered over 20 years, plus the Top 5 Team Building Tech Execs I’ve found, too.

Something Weird Happened: I Love My Job Again

By Kendra Little in SQL Server

March 26, 2024

Back in my 20’s, I was lucky enough to go to graduate school. I had a work-study job in the Dean’s office where I got to develop and administer their Access databases, which helped me get by. One day, the Dean said to me: “Kendra, when you talk about your work on our databases, you light up. When you talk about your coursework, that doesn’t happen. Have you thought about that?

You Will Not Find Long Compilers Who Time Out in Query Store

By Kendra Little in SQL Server

March 5, 2024

Last November, a puzzle was really bothering me. Some queries from an application were timing out frequently after running for 30 seconds, but they were halfway invisible in the SQL Server.

How to Start an XEvents Trace on a Read Scale-Out Azure SQL Managed Instance

By Kendra Little in SQL Server, Azure SQL Managed Instance

February 29, 2024

It took me more than half hour to figure out how to start an XEvents trace on a read-scale out instance of Azure SQL Managed Instance. It’s hard to monitor read scale-out instances, so tracing is desirable! I started with a simple trace of sql_statement_completed. Hopefully this saves other folks some time.

Should You Use SQL Server Readable Secondaries if Queries Can Fail Repeatedly at Any Time?

By Kendra Little in SQL Server

February 21, 2024

If you use readable secondaries in Availability Groups or Read-Scale out instances in Azure SQL Managed Instance, you may have queries fail repeatedly if there is a glitch and statistics are not successfully “refreshed” on the secondary replica. Those queries may keep failing until you manually intervene.

It’s unclear if Microsoft will ever fix this. There is a well established support deflection article which documents the issue and provides ‘workarounds’.