In the previous article of this series, we saw how to extract WAL records related to the exact SQL commands we want, INSERTs on heap tables, and what the structure of those records was. In this article we will focus on the heap specific information contained in those records and how to extract SQL queries from them.

Write-Ahead Logs is a critical part of PostgreSQL, that ensures data durability. While there are multiple configuration parameters , there was no easy to monitor WAL activity, or what is generating it.

Selectivity estimation error is one of the main cause of bad query plans. It’s quite straighforward to compute those estimation error using EXPLAIN (ANALYZE), either manually or with the help of explain.depesz.com (or other similar tools), but until now there were now tool available to get this information automatically and globally. Version 2 of pg_qualstats fixes that, thanks a lot to Oleg Bartunov for the original idea!

Coming up with good index suggestion can be a complex task. It requires knowledge of both application queries and database specificities. Over the year multiple projects tried to solve this problem, one of which being PoWA with the version 3, with the help of pg_qualstats extension. It can give pretty good index suggestion, but it requires to install and configure PoWA, while some users wanted to only have the global index advisor. In such case and for simplicity, the algorithm used in PoWA is now available in pg_qualstats version 2 without requiring any additional component.

This article is part of the PoWA 4 beta series, and describes the new powa-collector daemon.

This article is part of the PoWA 4 beta series, and describes the changes done in powa-archivist.

PoWA 4 is available in beta.

A new version of pg_stat_kcache is out, with support for Windows and other platforms, and more counters available.

You can now view the Wait Events in PoWA thanks to the pg_wait_sampling extension.

This blog post is a summary of a production issue I had to investigate some time ago with people from Oslandia, and since it’s quite unusual I wanted to share it with some methodology I used, if it can help anyone running into the same kind of problem. It’s also a good opportunity to say that upgrading to a newer PostgreSQL version is almost always a good idea.

After so much time missing this features, HypoPG implements hypothetical indexes support for PostgreSQl, available as an extension.

Last month, I had the chance to talk about PostgreSQL monitoring, and present some of the tools I’m working on at pgconf.ru.