Posts

Sequential UUID Generators on SSD

After I shared the sequential UUID benchmarks a couple of weeks ago, one of the points raised in feedback was the choice of the storage space. I’ve intentionally used a fairly weak storage system (RAID10 on three 7.2k SATA drives) because I wanted to demonstrate the benefits. But a couple of readers suggested using SSDs might significantly reduce […]

PostgreSQL Meltdown Benchmarks

Two serious security vulnerabilities (code named Meltdown and Spectre) were revealed a couple of weeks ago. Initial tests suggested the performance impact of mitigations (added in the kernel) might be up to ~30% for some workloads, depending on the syscall rate. Those early estimates had to be done quickly, and so were based on limited […]

PostgreSQL Meltdown

Spectre and Meltdown have caused severe alarm in recent days. You may have read about up to 30% impact on PostgreSQL databases, which I believe to be overstated because of misunderstandings in the media. Let’s dig into this in more detail. TL;DR Summary: no PostgreSQL patch required, -7% performance hit In response to these new […]

Benchmark on a Parallel Processing Monster!

Last year I wrote about a benchmark which I performed on the Parallel Aggregate feature that I worked on for PostgreSQL 9.6.  I was pretty excited to see this code finally ship in September last year, however something stood out on the release announcement that I didn’t quite understand: Scale Up with Parallel Query Version 9.6 […]

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 […]

Benchmarking Postgres-XL

As you may have noted from my previous blog, the last few months were busy in getting Postgres-XL up-to-date with the latest 9.5 release of PostgreSQL. Once we had a reasonably stable version of Postgres-XL 9.5, we shifted our attention to measure performance of this brand new version of Postgres-XL. Our choice of the benchmark […]