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This article introduces what the mysql database engine has, the content is very detailed, interested friends can refer to, hope to be helpful to you.

View the database engine command: SHOW ENGINES

ISAM

ISAM is a well-defined and time-tested data table management method. When it is designed, it takes into account that the number of times the database is queried is much greater than the number of updates. As a result, ISAM performs read operations very quickly and does not consume a lot of memory and storage resources. The two main drawbacks of ISAM are that it does not support transactions and is not fault tolerant: if your hard drive crashes, the data files cannot be recovered. If you are using ISAM in mission-critical applications, you must back up all your real-time data frequently, and MYSQL can support such backup applications through its replication feature.

MYISAM

MYISAM is MYSQL's ISAM extension format and default database engine. In addition to providing a large number of functions of index and field management that are not available in ISAM, MYISAM also uses a table locking mechanism to optimize multiple concurrent read and write operations. The cost is that you need to run the OPTIMIZE TABLE command frequently to recover the space wasted by the update mechanism. MYISAM also has some useful extensions, such as the MYISAMCHK tool to repair database files and the MYISAMPACK tool to recover wasted space.

MYISAM emphasizes fast read operations, which is probably the main reason why MYSQL is so popular with WEB developers: a lot of the data operations you do in WEB development are read operations. Therefore, most web hosting providers and INTERNET platform providers are only allowed to use the MYISAM format.

HEAP

HEAP allows temporary tables that reside only in memory. Residing in memory makes HEAP faster than both ISAM and MYISAM, but the data it manages is unstable, and if it is not saved before shutting down, all data will be lost. HEAP doesn't waste a lot of space when data rows are deleted, and HEAP tables are useful when you need to use SELECT expressions to select and manipulate data. Remember to delete the form after you finish using it.

INNODB and BERKLEYDB

Both INNODB and the BERKLEYDB (BDB) database engine are direct products of the technology that makes MYSQL flexible, which is MySql++ API. Almost every challenge you face when using MySql stems from the fact that the ISAM and MYIASM database engines do not support transactions or foreign keys. Although much slower than the ISAM and MYISAM engines, INNODB and BDB include support for transactions and foreign keys that the first two engines do not have. As mentioned earlier, if your design requires one or both of these features, you will be forced to use one of the last two engines.

What about the mysql database engine to share here, I hope that the above content can be of some help to you, can learn more knowledge. If you think the article is good, you can share it for more people to see.

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