Latest blog posts

Buyer Beware: Azure SQL Managed Instance Storage is Regularly as Slow as 60 Seconds

By Kendra Little on December 18, 2024

What are your stories of unbelievably bad performance from cloud vendors? I’ll go first. For years, Azure SQL Managed Instance’s General Purpose Tier has documented “approximate” storage latency as being “5-10 ms." This week they added a footnote: “This is an average range. Although the vast majority of IO request durations will fall under the top of the range, outliers which exceed the range are possible.” How approximate is that 5-10 milliseconds, you might wonder?

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Query Hash Values are Meaningless in SQL Server: They May be Reset to be the Same Value as the Query Plan Hash

By Kendra Little on November 24, 2024

This is the worst bug I’ve found in SQL Server to date. Previously, my top find was SQL Server Online Index Rebuild sometimes happens offline without warning. This one has taken top slot because it makes my life more difficult on a daily basis. Background: SQL Server generates a query_hash for each query. This is stored in sys.query_store_query and it’s one of the primary ways you can identify what a query is across different Query Stores, or even the same Query Store over time, as surrogate query_id values get reset if Query Store is cleared or data ages on.

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What Is the CPU Wait in Datadog SQL Server Monitoring? How does it Compare to Waiting on CPU?

By Kendra Little on November 21, 2024

I use Datadog on a regular basis, and I’m a pretty huge fan. The monitoring pack for SQL Server (and its PAAS variants) is still pretty rudimentary, but it evolves regularly. That’s NOT what I’m a fan of, though. What makes me a raving fan is the flexibility of Datadog’s notebooks and dashboards, combined with the ability to create all sorts of custom metrics and monitors. There are always things in SQL Server monitoring packs that I have strong opinions about.

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How to Survive Opening A Microsoft Support Ticket for SQL Server or Azure SQL

By Kendra Little on September 23, 2024

Asking Microsoft for support for SQL Server or Azure SQL is a lousy experience these days. This is true whether you are using a cheaper service tier or the more expensive support tier formerly known as “Premiere Support.” Either way, I’ve found the same issues: as the person requesting support, I must know a whole lot about the root cause of my problem and how to solve it, or my request will be dismissed with misinformation. I need to have data and metrics that back up my claims in order to get the ticket escalated to someone who can help, and I will need to provide those receipts three or four times. Once something is escalated to the Product Group, I may get a helpful response, but it will generally take a while. If I’m not engaged directly with the Product Group and the answer is being relayed through a lower support tier, it often won’t make much sense.

These issues don’t happen due to bad work ethics or personal failings of support workers. These are good humans, who are trying their best! The problem is worse, because it’s systemic.

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Latest SQLComics

SQL Corgs Explain Inner Joins

on April 15, 2024

Joins are essential. The SQL Corgs introduce you to INNER joins in this animated short.

LOOK HERE

Awkward Unicorn Explains Database Normalization

on April 3, 2024

Why do we “normalize” relational databases, and what are the basics? Awkward Unicorn explains, with a little help from their friends.

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SQL Basics (SELECT, FROM, WHERE) with Freyja the Corgi

on April 1, 2024

Freyja the corgi shares her tips for learning SQL: SELECT, FROM, and WHERE.

Now that I’m getting the hang of this, I think I’m going to do a whole series of shorts on SQL syntax essentials, plus tips and tricks!

LOOK HERE

Rita the Raccoon Writes SQL

on March 28, 2024

I learned to make short form videos with my drawings this week, and, well… things are about to get weirder.

LOOK HERE