When teaching PostgreSQL trainings, both on basics and advanced topics, I often find out the attendees have very little idea how powerful the expression indexes may be (if they are aware of them at all). So let me give you a brief overview. So, let’s say we have a table, with a range of timestamps (yes, we have generate_series function that can generate dates): CREATE TABLE t AS SELECT d, repeat...

Although in the future most database servers (particularly those handling OLTP-like workloads) will use a flash-based storage, we’re not there yet – flash storage is still considerably more expensive than traditional hard drives, and so many systems use a mix of SSD and HDD drives. That however means we need to decide how to split the database – what should go to the spinning rust (HDD) and what...

In the previous blog post, I briefly explained how we got the performance numbers published in the pglogical announcement. In this blog post I’d like to discuss the performance limits of logical replication solutions in general, and also how they apply to pglogical. physical replication Firstly, let’s see how physical replication (built into PostgreSQL since version 9.0) works. A somewhat...

A few days ago we released pglogical, a fully open-source logical replication solution for PostgreSQL, that’ll hopefully get included into the PostgreSQL tree in a not-too-distant future. I’m not going to discuss about all the things enabled by logical replication – the pglogical release announcement presents a quite good overview, and Simon also briefly explained the advantages of logical...