Daniel Westermann

PostgreSQL 17: Allow “\watch” to stop based on the number of rows returned

psql already is really powerful but still it gets more features with almost every release of PostgreSQL. One example is the “\watch” meta command. This command was introduced in PostgreSQL 9.3 and hasn’t changed much(…)

PostgreSQL 17: pg_wait_events

As development of PostgreSQL 17 already started there are already some commits which bring in new functionality. One of them introduces a new catalog view called “pg_wait_events”. As the same implies, this view lists the known wait events for(…)

PostgreSQL 16: Playing with pg_stat_io (2) – evictions

In the last post in this little series we’ve looked at the “extends” statistic in pg_stat_io. In this post we’ll look at the “eviction” statistic. Before we go into the details:(…)

PostgreSQL 16: Playing with pg_stat_io (1) – extends

PostgreSQL 16 (currently in beta 2) will come with a new view for tracking I/O related statistics. I’ve written a very basic blog about pg_stat_io in the past. In this post(…)

Generated columns in PostgreSQL

Sometimes it becomes handy when you can auto-generate a column based on an expression. For this there is the concept of generated column. Those columns can be either of type “stored” (the derived value is computed when the column(…)

PostgreSQL: System catalog modifications are currently disallowed

Today at a customer I faced this: “System catalog modifications are currently disallowed” which, honestly, I’ve never seen before. Why would someone try to modify the system catalogs, at least in a productive environment? It turned out to be(…)

Between PostgreSQL Conference Germany 2023 and the Swiss PGDay 2023

The PostgreSQL Conference Germany 2023 is over and it was a success. We had 250 attendees which made this year’s edition of the conference the largest ever. For us the conference already started Monday evening with the(…)

PostgreSQL 16: More statistics in pg_stat_*_tables

PostgreSQL 16 is already in feature freeze and Beta1 has been released on May 25th. This is the time you should start testing and report any issues back to the community. There are plenty of new features, as usual,(…)

2023.pgconf.de and the Swiss PGDay are just around the corner

Time flies, we are in June already and at the end of this month two PostgreSQL conferences will take place: There is 2023.pgconf.de, this year in Essen, the 27th of June. For the first time(…)

How a merge join produced the wrong result in PostgreSQL

This was a really interesting customer case and I learned a lot by troubleshooting this. The original request was: We have two databases connected via postgres_fdw and when a merge join is chosen by PostgreSQL(…)