October 23, 2014

Is your MySQL Server Loaded ?

So you’re running the benchmark/stress test – how do you tell if MySQL server is really loaded ? This looks like the trivial question but in fact, especially when workload consists of simple queries I see the load generation and network really putting a lot less load on MySQL than expected. For example you may […]

Star Schema Bechmark: InfoBright, InfiniDB and LucidDB

In my previous rounds with DataWarehouse oriented engines I used single table without joins, and with small (as for DW) datasize (see http://www.percona.com/blog/2009/10/02/analyzing-air-traffic-performance-with-infobright-and-monetdb/, http://www.percona.com/blog/2009/10/26/air-traffic-queries-in-luciddb/, http://www.percona.com/blog/2009/11/02/air-traffic-queries-in-infinidb-early-alpha/). Addressing these issues, I took Star Schema Benchmark, which is TPC-H modification, and tried run queries against InfoBright, InfiniDB, LucidDB and MonetDB. I did not get results for MonetDB, will […]

InnoDB: look after fragmentation

One problem made me puzzled for couple hours, but it was really interesting to figure out what’s going on. So let me introduce problem at first. The table is

Table has 11864696 rows and takes Data_length: 698,351,616 bytes on disk The problem is that after restoring table from mysqldump, the query that scans data […]

MySQL File System Fragmentation Benchmarks

Few days ago I wrote about testing writing to many files and seeing how this affects sequential read performance. I was very interested to see how it shows itself with real tables so I’ve got the script and ran tests for MyISAM and Innodb tables on ext3 filesystem. Here is what I found: