Data Storage

Innodb

See ha_innobase or read details about InnoDB internals:

• Innodb data lock instrumentation
• Innodb redo log
• Innodb Lock-sys
• Innodb utils

Temp table

Before 8.0, temporary tables were handled by heap engine. The heap engine had no feature to store bigger tables on disk.

Since 8.0, there is a brand new temptable engine, which is written from scratch using c++11. It has following advantages:

• it is able to store bigger tables on disk (in temporary files),
• it uses row format with variable size (can save memory for varchars),
• it is better designed (easier to maintain).

TempTable storage engine