MySQL Engine introduction

MysqlEngine IntroductionInnodbStorage Engine

2. support transactions, in OLTP support row-level lock, foreign key;

4. concurrency control via multiple versions MVCC to achieve high concurrency, and implement 4 isolation levels for SQL (default repeatable);

6. provides insert buffer,double write, adaptive Hash index, pre-read;

8. for storage of data in tables,InnoDB uses clustered. The storage of each table is stored in the order of the primary key, and if the table does not explicitly define a primary key,InnoDB generates a 6 -byte rowid for each row as the primary key.

MyisamStorage Engine

1. transactions are not supported, table locks, full-text indexes, Fast OLAP operation;

2. The storage engine has MYD and MYI composition,MYD put data files,MYI put index files;

3. starting with MySQL 5.0, 256T single- table data is supported by default ;

4. for the MyISAM Storage Engine table,the MySQL database caches only its index files, and the cache of the data files is done by the OS itself, as distinct from the use of LRU The algorithm caches most of the data in the database.

NDBStorage Engine

1. The data is put in memory, the primary key is very fast, can improve the database performance linearly, high availability, high performance cluster system;

2. the connection operation of the NDB storage engine is done at the MySQL database layer, not the storage engine layer, so complex connection operations require significant network overhead.

MemoryStorage Engine

1. put the table's data in memory, and if the database restarts or crashes, the data in the table is lost. A temporary table for storing temporary data, a latitude table in a data warehouse, a hash index by default , and a non- B + tree index;

2. only table locks are supported, poor concurrency, text and blob types are not supported, and when you store a variable-length field varchar, you are wasting space by using the fixed-length field char method.

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MySQL Engine introduction