compression feature was
recommended primarily for read-only or read-mostly
workloads, such as in a
configuration. The rise of SSD
storage devices, which are fast but relatively small and
expensive, makes compression attractive also for
OLTP workloads: high-traffic, interactive web
sites can reduce their storage requirements and their I/O
operations per second (IOPS) by
using compressed tables with applications that do frequent
Configuration options introduced in MySQL 5.6 let you adjust the way compression works for a particular MySQL instance, with an emphasis on performance and scalability for write-intensive operations:
innodb_compression_levellets you turn the degree of compression up or down. A higher value lets you fit more data onto a storage device, at the expense of more CPU overhead during compression. A lower value lets you reduce CPU overhead when storage space is not critical, or you expect the data is not especially compressible.
innodb_compression_failure_threshold_pctspecifies a cutoff point for compression failures during updates to a compressed table. When this threshold is passed, MySQL begins to leave additional free space within each new compressed page, dynamically adjusting the amount of free space up to the percentage of page size specified by
innodb_compression_pad_pct_maxlets you adjust the maximum amount of space reserved within each page to record changes to compressed rows, without needing to compress the entire page again. The higher the value, the more changes can be recorded without recompressing the page. MySQL uses a variable amount of free space for the pages within each compressed table, only when a designated percentage of compression operations “fail” at runtime, requiring an expensive operation to split the compressed page.
innodb_log_compressed_pageslets you disable writing of images of re-compressed pages to the redo log. Re-compression may occur when changes are made to compressed data. This option is enabled by default to prevent corruption that could occur if a different version of the
zlibcompression algorithm is used during recovery. If you are certain that the
zlibversion will not change, disable
innodb_log_compressed_pagesto reduce redo log generation for workloads that modify compressed data.
Because working with compressed data sometimes involves keeping
both compressed and uncompressed versions of a page in memory at
the same time, when using compression with an OLTP-style
workload, be prepared to increase the value of the