Posts

PG Phriday: Postgres on ZFS

ZFS is a filesystem originally created by Sun Microsystems, and has been available for BSD over a decade. While Postgres will run just fine on BSD, most Postgres installations are historically Linux-based systems. ZFS on Linux has had much more of a rocky road to integration due to perceived license incompatibilities. As a consequence, administrators […]

On the impact of full-page writes

While tweaking postgresql.conf, you might have noticed there’s an option called full_page_writes. The comment next to it says something about partial page writes, and people generally leave it set to on – which is a good thing, as I’ll explain later in this post. It’s however useful to understand what full page writes do, because […]

PostgreSQL vs. Linux kernel versions

I’ve published multiple benchmarks comparing different PostgreSQL versions, as for example the performance archaeology talk (evaluating PostgreSQL 7.4 up to 9.4), and all those benchmark assumed fixed environment (hardware, kernel, …). Which is fine in many cases (e.g. when evaluating performance impact of a patch), but on production those things do change over time – […]

Tables and indexes vs. HDD and SSD

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 […]

On pglogical performance

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 […]