Very often, database performance is affected by the inability to cache all the required data in memory. Disk IO, even when using the fastest devices, takes much more time than a memory access. With MySQL/InnoDB, the main memory cache is the InnoDB buffer pool. There are many strategies we can try to fit as much data as possible in the buffer pool, and one of them is data compression.

With regular MySQL, to compress InnoDB data you can either use “Barracuda page compression” or “transparent page compression with punch holes”. The use of the ZFS filesystem is another possibility, but it is external to MySQL and doesn’t help with caching. All these solutions are transparent, but often they also have performance and management implications. If you are using Percona Server for MySQL, you have yet another option, “column …

In this blog post, we’ll look at some of the facets of InnoDB page compression.

Somebody recently asked me about the best way to handle JSON data compression in MySQL. I took a quick look at InnoDB page compression and wanted to share my findings.

There is also some great material on this topic that was prepared and presented by Yura Sorokin at Percona Live Europe 2017: https://www.percona.com/live/e17/sessions/percona-xtradb-compressed-columns-with-dictionaries-an-alternative-to-innodb-table-compression. Yura also implemented …

MySQL has information_schema.tables that contain information such as “data_length” or “avg_row_length.” Documentation on this table however is quite poor, making an assumption that those fields are self explanatory – they are not when it comes to tables that employ compression. And this is where inconsistency is born. Lets take a look at the same table containing some highly compressible data using different storage engines that support MySQL compression:

TokuDB:

mysql> select * from information_schema.tables where table_schema='test' G
*************************** 1. row ***************************
TABLE_CATALOG: def
TABLE_SCHEMA: test
TABLE_NAME: comp
TABLE_TYPE: BASE TABLE
ENGINE: TokuDB
VERSION: 10
ROW_FORMAT: tokudb_zlib
TABLE_ROWS: 40960
AVG_ROW_LENGTH: 10003
DATA_LENGTH: 409722880
MAX_DATA_LENGTH: …