Mysql storage engine Overview

Different from most databases, mysql has a storage engine. For different needs, you can select the storage engine that best suits you. How many storage engines are there in mysql, what are their advantages and disadvantages,

The mysql tutorial is different from most database tutorials. There is a storage engine in mysql. You can select the storage engine that best suits your needs. How many storage engines are there in mysql, what are their advantages and disadvantages,

Mysql engines include myisam, innodb, bdb, memory, merge, example, ndb cluster, archive, csv, blackhole, federated, and other innodb engines, and bdb provide transaction security tables, and other storage engines are non-transaction security tables.

Next, let's take a look at the conciseness of different tables.

1. myisam

Myisam is the default storage engine of mysql. It does not support transaction processing and Foreign keys. Its advantage is that it is fast and has no requirements on transaction integrity,

Myisam is a data table that has three table files on the hard disk:. frm (storage table definition). myd (Data Storage table). myi (storage index table)

Ii. innodb

The auto-increment column of the innodb table, which can be manually input. However, if the value is 0 or null, the actual inserted value will automatically increase, the automatic growth of innodb tables must be set as indexes, and myisam is not required. It also supports foreign key constraints,

Iii. memory

The memery storage engine uses the content stored in the memory to create a table. Each memory table corresponds to only one hard disk file. The format is. frm and memory access speed is faster than the above two because the data is stored in the memory and the default engine uses hash indexes. However, when the server is disabled, the data in the table will be lost.

Iv. merge

The merge storage engine is a combination of a group of myisam tables. These myisam tables must have the same structure. merge itself has no data and can query, delete, and update merge tables, these operations are actually performed on the internal myisam. For merge-type table insertion operations, the inert_method clause is used to define the inserted Table. There can be three different values, first, last, table no cannot insert merge.

Well, the above is a simple description of the commonly used mysql storage engine,

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