Administration – Page 3

Postgres vs Kubernetes container_memory_working_set_bytes

Published 2026-08-19 by Kevin Feasel

Jeremy Schneider provides an alternative:

Kubernetes metric container_memory_working_set_bytes is used for evicting/killing pods with too much memory use, especially if memory request < limit (don’t do this with Postgres). The metric is calculated from cgroups v2 memory.stat as current-inactive_file [source].

You’d assume it’s a good metric for memory usage in kubernetes. But with Postgres, this metric is very inaccurate for memory utilization and doesn’t tell you at all if you’re going to OOM crash your database.

Click through to understand what goes wrong, why it does, and what you can use instead.

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The Importance of Disaster Recovery Testing

Published 2026-08-18 by Kevin Feasel

Vlad Drumea performs some tests:

After the ANCPI hack that took down Romania’s land registry, Andrei Avădănei, CEO of Bit Sentinel and founder of DefCamp, published on LinkedIn a detailed proposal for a national offensive security program.
It covered pentesting frameworks, vulnerability disclosure, continuous monitoring, and accountability measures. The proposal was thorough, logical, and exclusively focused on prevention and detection.

I left a comment suggesting one addition: mandatory disaster recovery simulations.
Can institution X recover after their entire production environment is encrypted? If so, how long does it take and what data is lost? Are there backups? And if yes, are they actually viable, or are they Schrödinger’s backups, where you only find out whether they work at the exact moment you need them?

This exchange made me realize that organizations, especially in the public sector, rarely consider doing disaster recovery tests.

I’ve been on the edges of DR scenarios at prior jobs, including one at a state agency. Most of the time, the tests have to be hypothetical or piecemeal because we rarely had the hardware to support a full switch-over, or the budget to spin up an equivalent set of hardware in a different region.

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Diagnosing High-Cardinality Workloads in Postgres

Published 2026-08-14 by Kevin Feasel

Ryan Booz has a video:

In Part 6 of this special Postgres in Production deep dive series, Ryan Booz asks a question that determines how useful pg_stat_statements can be for you at all: do you have a high cardinality workload? This episode covers what that actually means, why ORMs, dynamic SQL, and AI-assisted development tools generate more unique queries than you might expect, a side by side demo of the same workload on Postgres 17 and Postgres 18, and the concrete checks that tell you whether pg_stat_statements is losing the data you need for query tuning.

Click through for the video and transcript.

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Deletion and Ghost Cleanup in SQL Server

Published 2026-08-13 by Kevin Feasel

Martyn Jones hunts down the ghosts:

The concepts discussed in the previous blog post can also be seen in the transaction log. The logical removal of rows (by marking them as ghost records), the associated allocation metadata updates, and the eventual physical removal of those rows by the ghost cleanup process are recorded as individual transaction log operations.

The demo code uses the undocumented function fn_dblog(), this provides a clear view of the internal sequence of events that SQL Server performs during a delete operation so the individual physical changes required to implement ghosting, and later, cleanup can be studied.

Click though to see how SQL Server marks ghost records, tracks where they are, and performs cleanup.

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Building an Attack Profile for msdb

Published 2026-08-11 by Kevin Feasel

Fabiano Amorim takes us through a thought process:

SQL Server DBAs routinely rely on automation: SQL Server Agent jobs, maintenance plans, refresh processes, restore scripts, replication cleanup, CDC operations, cross-database modules, and temporary objects. These workflows are often trusted because they’re normal – and that’s precisely why they deserve more attention.

The goal of this article is not to provide exploit recipes. Instead, it’s to help DBAs answer a practical question: how do I know whether my SQL Server instances are exposed to this kind of risk, what should I monitor, and what should I change when I find a problem?

Click through for the process.

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Building Oracle’s Automatic Workload Repository in Postgres

Published 2026-08-05 by Kevin Feasel

Kellyn Gorman simulates some functionality:

Moving from Oracle to PostgreSQL means losing one of Oracle’s most-loved diagnostic tools: the Automatic Workload Repository (AWR). The good news? Most of AWR’s core capabilities – snapshot history, wait event sampling, Top SQL analysis, and buffer cache inspection – have direct, open-source equivalents in PostgreSQL.

This guide translates Oracle AWR concepts into practical PostgreSQL diagnostics using extensions like pg_profile, pg_wait_sampling, and pg_stat_statements – complete with runnable SQL you can apply to your own environment today.

Read on to see how.

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DOP Non-Feedback

Published 2026-08-04 by Kevin Feasel

Rebecca Lewis tries to get some feedback:

In my DOP Feedback post last month, I shared something very frustrating. I had all the documented prerequisites for DOP Feedback in place. Query Store in READ_WRITE mode, DOP_FEEDBACK enabled at the database scope, Compatibility Level 160, MAXDOP set to 14, and a repeatable workload generating real parallelism waits — but the DOP feedback never fired. No dop_feedback_eligible_query event. No entries in sys.query_store_plan_feedback. Nothing.

I said I’d follow with a sequel when I found a workload that does become eligible, and then I’d compare it against the one that did not. Well. This is that sequel, but I still don’t have it. Today is honestly my fourth full-day of testing without triggering any DOP Feedback.

Click through to learn what doesn’t work. Or at least didn’t work for Rebecca.

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Optimized Locking in SQL Server 2025

Published 2026-07-30 by Kevin Feasel

Louis Davidson tries out a new feature:

A feature I have been trying to find time to write about since it arrived is Optimized Locking, which first shipped in SQL Server 2025. This is a feature that changes the way SQL Server locks manages concurrency in a very interesting number of ways. Most of which, as I start writing this blog, I don’t understand. And I probably won’t when I finish.

What I can promise you is an example rich blog where I examine the impact of this feature.

Read on to see what Louis was able to learn.

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Test and Validate Azure SQL Database Migrations

Published 2026-07-27 by Kevin Feasel

Marlon Ribunal has a tool:

Introducing azsql-migration-test, a small open-source CLI that validates your Azure SQL Database migrations against a local Azure SQL Database Developer container — the same engine as the cloud, running on your machine.

The problem: proving a migration works shouldn’t require the cloud

The tool is AI-generated and it looks like the blog post is as well, but it does look to be useful.

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MSDB 110_upgrade.sql Failed with Error 574

Published 2026-07-22 by Kevin Feasel

Jordan Boich troubleshoots an issue:

SQL Server won’t start and at first, I couldn’t figure out why. When I logged off for the day on Friday, everything was happy, but when I logged on Monday morning, a heavily used test instance of SQL was not running and wouldn’t start.

Quick side note, and it’s funny looking back on now, but in the moment it sucks. You ever have to start the SQL Server Service from Configuration Manager, and when you right click -> Start, or right click -> Restart you see that green progress bar start to go and under normal healthy circumstances, it probably gets a third of the way through before SQL kicks over. But when you start to see that progress bar start to make more and more progress, you know before it even fails on you that something isn’t going to work right. You start to get that sinking feeling in your stomach. That was me.

Click through for the troubleshooting process as well as the end result.

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Category: Administration