Databases Archives | n0derunner

Postgres pgbench scale-factors and WSS

Published: August 11, 2020 (Updated: August 11, 2020) in Postgres, pgbench, postgres by gary. Leave a Comment on Postgres pgbench scale-factors and WSS.

Scale factor to workingset size lookup for tiny databases

How to drop tables for HammerDB TPC-H on SQL Server

Published: June 9, 2020 (Updated: July 1, 2020) in SQL Server, Testing & Benchmarking, hammerDB, sqlserver, tpc-h by gary. Leave a Comment on How to drop tables for HammerDB TPC-H on SQL Server.

Use the following SQL to drop the tables and indexes in the HammerDB TPC-H schema, so that you can re-load it.

SQL Server uses only one NUMA Node with HammerDB

Published: October 7, 2019 (Updated: October 8, 2020) in SQL Server, hammerDB, sqlserver by gary.

Some versions of HammerDB (e.g. 3.2) may induce imbalanced NUMA utilization with SQL Server. This can easily be observed with Resource monitor. When NUMA imbalance occurs one of the NUMA nodes will show much larger utilization than the other. E.g. The cause and fix is well documented on this blog. In short HammerDB issues a […]

HammerDB: Avoiding bottlenecks in client.

Published: October 4, 2019 (Updated: October 8, 2020) in Databases, Testing & Benchmarking, benchmarking, database, hammerDB, sqlserver by gary.

How to avoid bottlenecks in the client generator when measuring database performance with HammerDB

Measuring CPU performance with X-Ray and pgbench.

Published: October 1, 2019 (Updated: October 8, 2020) in Postgres, postgres, x-ray by gary.

An X-ray workload for measuring application density

How to run vertica vioperf tool

Published: September 6, 2019 (Updated: October 8, 2020) in Databases, Testing & Benchmarking, database, fio, vertica by gary.

The vertica vioperf tool is used to determine whether the storage you are planning on using is fast enough to feed the vertica database. When I initially ran the tool, the IO performance reported by the tool and confirmed by iostat was much lower than I expected for the storage device (a 6Gbit SATA device […]

View from Nutanix storage during Postgres DB benchmark

Published: June 28, 2019 (Updated: March 15, 2020) in Nutanix, Postgres, database, postgres by gary.

Following on from the previous [1] [2] experiments with Postgres & pgbench. A quick look at how the workload is seen from the Nutanix CVM. The Linux VM running postgres has two virtual disks: One is taking transaction log writes. The other is doing reads and writes from the main datafiles. Since the database size […]

Benchmarking with Postgres PT2

Published: June 28, 2019 (Updated: March 15, 2020) in Postgres, benchmarks, database, postgres by gary.

In this example we run pgbench with a scale factor of 1000 which equates to a database size of around 15GB. The linux VM has 32G RAM, so we don’t expect to see many reads. Using prometheus with the Linux node exporter we can see the disk IO pattern from pgbench. As expected the write […]

Benchmarking with Postgres PT1

Published: June 28, 2019 (Updated: March 15, 2020) in Postgres, benchmarks, database, postgres by gary.

In this example, we use Postgres and the pgbench workload generator to drive some load in a virtual machine. Assume a Linux virtual machine that has Postgres installed. Specifically using a Bitnami virtual appliance. Once the VM has been started, connect to the console Allow access to postgres port 5432 – which is the postgres […]

Performance gains for postgres on Linux with hugepages

Published: March 7, 2019 (Updated: March 15, 2020) in Performance Tuning, hugepages, linux, postgres, tuning by gary.

For this experiment I am using Postgres v11 on Linux 3.10 kernel. The goal was to see what gains can be made from using hugepages. I use the “built in” benchmark pgbench to run a simple set of queries. Since I am interested in only the gains from hugepages I chose to use the “-S” […]

SuperScalin’: How I learned to stop worrying and love SQL Server on Nutanix.

Published: November 23, 2014 (Updated: March 15, 2020) in SQL Server, benchmark, hammerDB, sql-server, tpc-c by gary. 3 Comments on SuperScalin’: How I learned to stop worrying and love SQL Server on Nutanix..

TL;DR It’s pretty easy to get 1M SQL TPM running a TPC-C like workload on a single Nutanix node. Use 1 vDisk for Log files, and 6 vDisks for data files. SQL Server needs enough CPU and RAM to drive it. I used 16 vCPU’s and 64G of RAM. Running database servers on Nutanix is an […]