Aleph Technologies Blog

Applications come and go, data stays.

Postgresql Performance on Ubuntu linux 18.04 and Amazon AWS EC2 iXL instance

Introduction This is a follow-up on our Postgresql Performance on Ubuntu 18.04 and Nutanix post. We document here the same pgbench tests on an Amazon EC2 i-XL instance with NVMe SSD storage. Disclaimer The following test results are not intended to give definitive numbers on the tested platform. These are only illustrative of the methodology used to test the platform for postgresql workloads. Sustained database benchmark with different linux kernel parameters We tested.. Read More

Postgresql Performance on Ubuntu linux 18.04 and Nutanix

Background On november 4, 2019, we were benchmarking a number of virtual machines on a new 12-node DELL 740XD-24 appliance under Nutanix AHV (and RDMA enabled). I was getting weird results and I tweeted the following: At the moment we were configuring both the Nutanix appliance and the Linux kernel parameters most suitable for a postgresql 9.5 specific workload. That was not a good idea and produced confusing test results since the actual.. Read More

Improving fuzzy searches in postgresql with pg_trgm

I have been researching postgresql search capabilities for quite a while. Besides the very powerful Full Text Search capabilities the engine offers today, there are a few less known index types that support string searches in the form : where foo like ‘%bar%’ For these cases, a regular b-tree index on ‘foo’ is guaranteed to never be used. The following example illustrates a case in which a relatively simple query is transformed to.. Read More