Andy Levy shares some thoughts:

I’ve spent a lot of time over the past 8 or years trying to “right the ship.” Systems that have been built and evolved over 10-15 years and the cracks are starting to show. Yes, there’s always the hot spot code that desperately needs attention, the stored procedure that runs in 6 hours but could be 20 minutes with the right adjustments. But I’m looking at a macro level today, more “operational” than “surgical.” When I see __ in a chunk of code, it’s a signal to me that there are overarching problems in how the whole system I’m working on was built and it’s going to take me a good, long while to undo that to deliver constant performance as data grows or improve maintainability.

Andy’s main topic is pre-populated temp tables serving as lookup tables in queries. Though if Andy wants eldrich temp table horrors, I raise him global temp tables (##table) created from a separate session and a SQL Agent job that runs every minute to create it, with people ignoring the failures because “That’s how it’s supposed to work.”

I’ve never seen that in practice, but now I kind of want to do it.

Bonus comment: leading semi-colons for CTEs. I rarely do that, but when I do, it’s because a semi-colon on the same line as a batch separator doesn’t count. In other words,

GO;

WITH records as (...)

returns an error. There might be some workable variant, admittedly, but in those cases, I do put the semi-colon in front of the CTE. The rest of the time, when I know there isn’t a batch separator right before the common table expression, I of course don’t. Commas and semi-colons belong at the end, not the beginning.

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Mala Mahadevan takes advantage of an extra week:

I just managed to get a post in for this landmark T-SQL Tuesday, hosted by Brent Ozar. Brent was kind enough to keep the submission window open for two weeks instead of the usual one, and I was able to sneak a post in last – minute.

His invitation is to write about the things that immediately stand out as “bad signs” when reviewing a SQL query.

Click through for Mala’s list. It’s a good list. While some items Mala calls out are defensible and quite reasonable, there are some of them (such as a LEFT OUTER JOIN whose columns show up in the WHERE clause for filtering) that are simply not.

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Todd Kleinhans provides a suggestion:

What is a linter? Does it work on actual lint?

No, not really. It comes from what could be called or referred to as best practices or guidance originally from the C programming language to perform static program analysis. It helps prevent bugs and follows the concept of “prevention is the cure”.

Click through for a bit of advice around linting, comments, and more.

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Thomas Williams has a list:

Nowadays I look after 3rd-party databases more than internally-developed ones, so I accept there’s a whole lot of ex-best practices, vendor preferences, and possibly shortcuts in queries I might come across – whether it’s a poorly-performing query, a blocker, or an error.

(Although, when I developed software more frequently, I was guilty of all the gripes below. My start in SQL, last century, was poring over a big yellow “For Dummies” book. I was the dummy.)

Click through for the list. I particularly hate tibbling, a rather derisive term for the malformed version of Hungarian notation. This would just lead me down a rant about how systems Hungarian notation was a mess, whereas apps Hungarian notation can be useful in certain circumstances. Tibbling provides no semantically valuable information, which is why I dislike it so much.

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Rob Farley has a few:

I feel like I should preface this with a disclaimer. I added “potentially-” to the title, because there are many queries that might seem bad but can actually perform just fine. There are queries that on the surface can be great, but are nasty without a particular index, and there are queries that make me cringe a little when looking at them, but are actually okay. Brent Ozar is asking about signs of bad code for this month’s T-SQL Tuesday (the 200th – and I have a response for all 200 if you look back through my history of posts), and he wants us to write this for 2004 Brent, rather than 2026 Brent.

Click through for what Rob has come up with. I agree with all of Rob’s examples and do appreciate his usage of the APPLY operator as a way of solving one common problem.

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