Bad Data
A lot of the time when I see queries that are written with all sorts of gymnastics in the join or where clause and I ask some questions about it, people usually start complaining about the design of …
Blog
Making The Most Of Temp Tables Part 1: Parallel Inserts
Sing Along
If you have a workload that uses #temp tables to stage intermediate results, and you probably do because you’re smart, it might be worth taking advantage of being able to insert into the #temp table in parallel.
Remember …
Announcing The Darling Data Vantablack Friday Sale!
A Word From Our Sponsors
First, a huge thank you to everyone who has bought my training so far. You all are incredible, and I owe all of you a drink.
Your support means a lot to me, and allows …
SQL Ciderday
Tis The Season
Look, it’s the Friday after Thanksgiving, and we’re both too tired to deal with SQL Server. Rather than get all worked up and worn out by talking about databases, today we’re going to talk about how to …
An Edge Case When Working With Date Parameters
Wheeze Man
When people tell you that working with correct data types is important, it’s for a variety of very good reasons.
Not only can you avoid performance issues, but you can avoid strange query plan distractions, too.
Let’s look …
Be Careful Where You Use AT TIME ZONE
Universal
Databases really do make you pay dearly for mistakes, and new linguistic functionality is not implemented with performance in mind.
I’ve written before about how to approach date math in where clauses: Where To Do Date Math In Your …
Troubleshooting RESOURCE_SEMAPHORE_QUERY_COMPILE Helper Queries
Unfortunate
RESOURCE_SEMAPHORE_QUERY_COMPILE happens, in a nutshell, when SQL Server has allocated all the memory it’s willing to give out to compile query plans of a certain size and, throttles itself by making other queries wait to compile. For more details, …
Announcing The Darling Data Vantablack Friday Sale!
A Word From Our Sponsors
First, a huge thank you to everyone who has bought my training so far. You all are incredible, and I owe all of you a drink.
Your support means a lot to me, and allows …
Why You Shouldn’t Ignore Filter Operators In Query Plans Part 2
If You Remember Part 1
We looked at a couple examples of when SQL Server might need to filter out rows later in the plan than we’d like, and why that can cause performance issues.
Now it’s time to look …
Why You Shouldn’t Ignore Filter Operators In Query Plans Part 1
Source Of Frustration
Ahem.
*taps mic*
When we write queries that need to filter data, we tend to want to have that filtering happen as far over to the right in a query plan as possible. Ideally, data is filtered …