How does InnoDB store tables in ibdata file?

Question

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 ?

Answer 1

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

• Apr 04, 2012 : How does innodb_stats_on_metadata relate to query execution plan stability?
• Jun 28, 2012 : Benefits of BTREE in MySQL
• Oct 26, 2012 : How badly does innodb fragment in the face of somewhat out-of-order insertions?
• Jan 09, 2013 : Is ANALYZE useful immediately after creating an InnoDB index?
• Mar 27, 2013 : Are there implicit indexes in InnoDB like MyISAM?
• Jun 14, 2013 : Does the size of the primary key contribute to table size?