Entries by Mark Wong

Visualizing sar data

Hopefully you are now regularly collecting system statistics after reading Tomas Vondra’s defense of using sar.  If you don’t have anything in place that readily visualizes the data, I have some examples that you can hopefully build off on to see everything you need to see. In addition to sar, the sysstat package also has […]


I had the pleasure of speaking about PostgreSQL performance at The 14th Annual Southern California Linux Expo and meeting many enthusiastic database users in the expo hall. There was a great turnout of people attending the conference, and many PostgreSQL presentations to see. Simon Riggs also talked about SERIALIZABLE, Eventual Consistency and Really Scary Stuff. […]

Testing Postgres-XL with DBT-3

As people have been working on merging Postgres-XL with the PostgreSQL 9.5 branch, I’ve been trying out Postgres-XL’s ability to run a decision support-like workload.  The DBT-3 test kit, originally developed at the OSDL as a TPC-H derivative, has some new changes so that it can run against Postgres-XL. I’ll describe how to use DBT-3 […]

Index Overhead on a Growing Table

This another simple test in continuation from last time. We will start with the same lineitem table as in the previous example. We will measure the time it takes to load the same 7.2GB text file repeatedly until the table size grows to about 1TB. We create a baseline with a table that has no indexes built on […]