After compiling Percona Server with TokuDB, of course I wanted to compare InnoDB performance vs TokuDB. I have a particular workload I’m interested in testing – it is an insert-intensive workload (which is TokuDB’s strong suit) with some roll-up aggregation, which should produce updates in-place (I will use INSERT .. ON DUPLICATE KEY UPDATE statements [...]
ALTER TABLE: Creating Index by Sort and Buffer Pool Size
June 27, 2012 By 4 Comments
Today I was looking at the ALTER TABLE performance with fast index creation and without it with different buffer pool sizes. Results are pretty interesting. I used modified Sysbench table for these tests because original table as initially created only has index on column K which initially contains only zeros, which means index is very [...]
A case for MariaDB’s Hash Joins
May 31, 2012 By Leave a Comment
MariaDB 5.3/5.5 has introduced a new join type “Hash Joins” which is an implementation of a Classic Block-based Hash Join Algorithm. In this post we will see what the Hash Join is, how it works and for what types of queries would it be the right choice. I will show the results of executing benchmarks [...]
Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
This is the second blog post in the series of blog posts leading up to the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. This blog post is aimed at the optimizer enhancement Multi Range Read (MRR). Its available in both MySQL 5.6 and MariaDB 5.5 Now let’s take a look at [...]
Improved InnoDB fast index creation
November 6, 2011 By 4 Comments
One of the serious limitations in the fast index creation feature introduced in the InnoDB plugin is that it only works when indexes are explicitly created using ALTER TABLE or CREATE INDEX. Peter has already blogged about it before, here I’ll just briefly reiterate other cases that might benefit from that feature: when ALTER TABLE [...]
Using any general purpose computer as a special purpose SIMD computer
May 16, 2011 By 5 Comments
Often times, from a computing perspective, one must run a function on a large amount of input. Often times, the same function must be run on many pieces of input, and this is a very expensive process unless the work can be done in parallel. Shard-Query introduces set based processing, which on the surface appears [...]
MySQL Partitioning – can save you or kill you
December 11, 2010 By 44 Comments
I wanted for a while to write about using MySQL Partitioning for Performance Optimization and I just got a relevant customer case to illustrate it. First you need to understand how partitions work internally. Partitions are on the low level are separate table. This means when you’re doing lookup by partitioned key you will look [...]
Star Schema Bechmark: InfoBright, InfiniDB and LucidDB
January 7, 2010 By 48 Comments
In my previous rounds with DataWarehouse oriented engines I used single table without joins, and with small (as for DW) datasize (see http://www.mysqlperformanceblog.com/2009/10/02/analyzing-air-traffic-performance-with-infobright-and-monetdb/, http://www.mysqlperformanceblog.com/2009/10/26/air-traffic-queries-in-luciddb/, http://www.mysqlperformanceblog.com/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 [...]
How many partitions can you have ?
December 5, 2009 By 19 Comments
I had an interesting case recently. The customer dealing with large MySQL data warehouse had the table which was had data merged into it with INSERT ON DUPLICATE KEY UPDATE statements. The performance was extremely slow. I turned out it is caused by hundreds of daily partitions created for this table. What is the most [...]
InnoDB: look after fragmentation
November 5, 2009 By 12 Comments
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
1 2 3 4 5 6 7 8 | CREATE TABLE `c` ( `tracker_id` int(10) unsigned NOT NULL, `username` char(20) character set latin1 collate latin1_bin NOT NULL, `time_id` date NOT NULL, `block_id` int(10) unsigned default NULL, PRIMARY KEY (`tracker_id`,`username`,`time_id`), KEY `block_id` (`block_id`) ) ENGINE=InnoDB |
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 [...]
