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InnoDB Table Fragmentation and Defragmentation, Free Space, Within MySQL Server (Doc ID 1338611.1)

Last updated on MAY 30, 2023

Applies to:

MySQL Server - Version 4.0 and later
Information in this document applies to any platform.

Goal

Check whether InnoDB tables are fragmented and optimise them if desired.


Solution

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In this Document
Goal
Solution
 Types of fragmentation
 1. Fragmentation within the filesystem when using innodb_file_per_table.
 2. Fragmentation within the shared tablespace, mainly if not using innodb_file_per_table
 3. Fragmentation of the data rows in the clustered index.
 4. Fragmentation within unique secondary index pages.
 5. Fragmentation within non-unique secondary index pages.
 6. Fragmentation of partitions
 7. Free space
 Combined defragmentation for all causes.
References


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