The PostgreSQL documentation has some information about row locks. But typically, you cannot see them in pg_locks, and not […]
ALTER TABLE ... ADD COLUMN … done right in PostgreSQL
Running ALTER TABLE … ADD COLUMN can cause serious issues in production. Understand how to cleanly change PostgreSQL data structures.
Transaction anomalies with SELECT FOR UPDATE
by
Laurenz Albe |
06.2022© Laurenz Albe 2022 I was recently confronted with a nice example of how adding FOR UPDATE to a query […]
Fixing out-of-sync sequences in PostgreSQL
This post shows how to deal with out of sync PostgreSQL sequences in underlying tables using open-source pg_sequence_fixer extension
Subtransactions and performance in PostgreSQL
by
Laurenz Albe |
03.2020 (Last updated on 2023-01-24) Recently, while troubleshooting PostgreSQL performance problems, I ran into problems with subtransactions twice. So I […]
"LOCK TABLE" can harm your database's health
by
Laurenz Albe |
03.2019 Many people know that explicit table locks with LOCK TABLE are bad style and usually a consequence of bad […]
xmax is a PostgreSQL system column that is used to implement Multiversion Concurrency Control (MVCC). The documentation is somewhat terse: […]
