Advanced learning of MySQL -- Application -- storage engine

mysql Architecture of

Work of all levels

adjoining course

Mainly completes some similar to the connection processing , Authorized certification , And related safety programs , The server will also verify the operation authority of each client for secure access .

Service layer

The second layer mainly completes some core services , And complete the cache query , SQL Analysis and optimization of , Execution of some built-in functions , All the cross storage engine functions are also implemented in this layer . Like the process , Functions, etc .

Engine layer

The storage engine is really responsible for MySQL Storage and reading of data in , Server pass API Communicating with the storage engine , Different storage engines have different functions , In this way, according to our own needs , To choose the right storage engine .

Storage layer

It mainly stores the data on the file system , And complete the interaction with the storage engine

Introduction to storage engine

The storage engine is to store data , Index , to update / Implementation of query data and other technologies , The storage engine is table based , Not library based , So the storage engine is also called table type . ( To put it bluntly , In a database , The engine of each table may be different )

Query key table statement

Found that the default engine is InnoDB.

Query the storage engine supported by the current database

show engines ;

Specify the engine when creating the table

Storage engine features

InnoDB

InnoDB Logical storage structure

therefore
The table space corresponds to ibd file .

The obvious , Row is the smallest unit of storage , And what information does a line contain ?
Last transaction id, Some pointers , There are also field information .

stay InnoDB In the logic of
Page is the smallest unit of disk operation , And the size is fixed 16K, The size of the zone is fixed . yes 1M. It means that there are 64 page .

MyISAM

Files involved in disk

Comparison summary

Storage engine selection

There is no good or bad engine , See the demand