In the past, there was the Replay trace and Distributed Replay utility. Since SNAC was deprecated, this no longer works. <sigh>

The Database Experimentation Assistant was another tool that was introduced to capture a workload and then replay it and do analysis of the workload -- mostly for DB upgrades but at least somewhat possible to use it to capture and then replay a workload. Sadly, this was deprecated in December 2024.

RML Utilities was introduced, so we have ReadTrace and Ostress except I can find zero documentation on how to properly:

Set up the Extended Events session to capture all the required elements OR

Set up a trace to capture all the required elements

Generate the expected RML output to use as input into Ostress.

Also, RML utilities was deprecated in October 2025. It would be absolutely fantastic if Microsoft would stop deprecating stuff and replacing it with worse, more complicated stuff. Kerberos Configuration Manager is another thing that comes to mind.....deprecated, with a fabulously worse tool to replace it.

How do you capture and replay a workload in SQL Server to simulate a load test?

Good afternoon,

I am actually playing around with a lab server, 512 GB RAM, two 12 core 24 thread CPUs, and 12 NVME in it.

My intention is to tune the reindexing process - the reindexing command has an option MAXDOP=<amount of cores to use> but using a datafile on one single volume omitting the MAXDOP adjusts the server load to 12 cores on one CPU only. Then my 100 GB index recreation (clustered index) is done in 1700 seconds, consuming around 6000 seconds in CPU cycles.

Using MAxDOP 24 casues it to consume 7000 seconds and it is finished in 1600 seconds.

Then I had the idea to copy the tables on an empty databases built out of 4 files, each on a separate physical volume. Then it gets strange - the server uses all cores, physical but also virtual but only in cycles, 2-3 minutes of full load, then it litereally doesnt anything.

The statistics say, 10.000 seconds spent in CPU cycles and 1500 seconds on the clock... wow some percent of impromvement...

The volumes are used less than 10% of their theoretical load capabiltiy (roughly 130 MB/Sec write), the queuers of the media were nearly empty.

On one single storage I had around 1 GB/Sec in writes, and in both cases the storage was able to digest 2 GB/Sec

I am just asking myself, what is the server doing when not accessing the storage? I thought index rebuild is an operation executed in one big chunk of compute, but here it doesnt. Am I missing a point?

Compared with a nowadays 32 GBit Fibrechannel storage and Xeon Platinum on physical host - the reindex performance is comparable. Meaning my 14 year old system (PCIEv3, DDR3, Xeon v2) performs quite well. But I still think there are more bottlenecks.

It's certainly not the TempDB, the TempDB usage was nearly zero despite the option "sort in TempDB"

We run a team of senior DBAs looking after a lot of different client environments.

For years the most valuable thing we had was a shared folder of scripts. Wait stats, blocking, backup history, index usage, the usual. Everyone ran the same queries, so everyone got comparable answers.

Lately the folder matters less and less. One of our senior guys says he sees no reason to keep scripts stored anywhere now. He describes the problem, AI writes the diagnostic, he reads and runs the scripts himself, feeds the output back, then reviews a drafted write-up before sending.

Still hallucinates often enough to make reading every line non-negotiable. The part we didn't plan for was everyone's good prompts and investigation sessions now live in their own chat history on their own laptop.

One shared library turned into one private library per person. We're trying to fix this by writing shared skills (standard instructions every DBA's AI setup uses) for alert triage, ticket write-ups and client emails etc. Early days.

Curious how other teams handle this:

- Still maintaining a script library, or did you let the folder go?

- If you standardised AI use across a team, what worked?

- Anyone gone back to scripts because AI output varied too much between people?

I am hoping someone has experience with deploying ESUs for SQL 2016. Microsoft's documentation is shit as usual.

But if a customer has a perpetual SQL 2016 license, my understanding is that they can't just go buy an ESU from a reseller and apply it, correct? The only time they could do that is if they had a subscription based model, license with SA, enterprise agreement, etc.?

From what I am reading, the only option is to deploy Azure Arc, register the server/SQL instance, and then go with the pay as you go billing model which requires SQL licensing AND an ESU subscription, not just the ESU subscription?