There are two tables and their default engine is InnoDB.

I want know the following

  • What's inside the ibdata file ?
  • How does InnoDB store these two tables ?

1 Answer 1


InnoDB Architecture

InnoDB Architecture

Percona created this picture a long time ago. As you can see, ibdata1 contains many classes of data structures. There are as follows:

  • Table Data Pages (if innodb_file_per_table disabled)
  • Table Index Pages (if innodb_file_per_table disabled)
  • Data Dictionary (Tablespace IDs, Logical-to-Physical Mapping to Tables)
  • Double Write Buffer (Handles Data Redundancy to Support Crash Recovery)
  • Insert Buffer (Handles Updates to Secondary Indexes)
  • Rollback Segments (Manages Reverse Engineering of Uncommitted Transactions)
  • Undo Space (Containers of Information for Rollback Operations)

BTREEs in InnoDB

If you are concerned how indexes are stored, please read my earlier posts about InnoDB indexes

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