MySQL 8.0 Release Notes
MySQL 8.0 Source Code Documentation
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InnoDB is a general-purpose storage engine that
balances high reliability and high performance. In MySQL
8.0, InnoDB is the default MySQL
storage engine. Unless you have configured a different default
storage engine, issuing a CREATE
TABLE statement without an ENGINE=
clause creates an InnoDB table.
Key Advantages of InnoDB
Its DML operations follow the ACID model, with transactions featuring commit, rollback, and crash-recovery capabilities to protect user data. See Section 15.2, “InnoDB and the ACID Model” for more information.
Row-level locking and Oracle-style consistent reads increase multi-user concurrency and performance. See Section 15.7, “InnoDB Locking and Transaction Model” for more information.
InnoDBtables arrange your data on disk to optimize queries based on primary keys. EachInnoDBtable has a primary key index called the clustered index that organizes the data to minimize I/O for primary key lookups. See Section 15.6.2.1, “Clustered and Secondary Indexes” for more information.To maintain data integrity,
InnoDBsupportsFOREIGN KEYconstraints. With foreign keys, inserts, updates, and deletes are checked to ensure they do not result in inconsistencies across different tables. See Section 15.6.1.5, “InnoDB and FOREIGN KEY Constraints” for more information.
Table 15.1 InnoDB Storage Engine Features
| Feature | Support |
|---|---|
| B-tree indexes | Yes |
| Backup/point-in-time recovery (Implemented in the server, rather than in the storage engine.) | Yes |
| Cluster database support | No |
| Clustered indexes | Yes |
| Compressed data | Yes |
| Data caches | Yes |
| Encrypted data | Yes (Implemented in the server via encryption functions; In MySQL 5.7 and later, data-at-rest tablespace encryption is supported.) |
| Foreign key support | Yes |
| Full-text search indexes | Yes (InnoDB support for FULLTEXT indexes is available in MySQL 5.6 and later.) |
| Geospatial data type support | Yes |
| Geospatial indexing support | Yes (InnoDB support for geospatial indexing is available in MySQL 5.7 and later.) |
| Hash indexes | No (InnoDB utilizes hash indexes internally for its Adaptive Hash Index feature.) |
| Index caches | Yes |
| Locking granularity | Row |
| MVCC | Yes |
| Replication support (Implemented in the server, rather than in the storage engine.) | Yes |
| Storage limits | 64TB |
| T-tree indexes | No |
| Transactions | Yes |
| Update statistics for data dictionary | Yes |
To compare the features of InnoDB with other
storage engines provided with MySQL, see the Storage
Engine Features table in
Chapter 16, Alternative Storage Engines.
InnoDB Enhancements and New Features
For information about InnoDB enhancements and new
features, refer to:
The
InnoDBenhancements list in Section 1.4, “What Is New in MySQL 8.0”.The Release Notes.
Additional InnoDB Information and Resources
For
InnoDB-related terms and definitions, see the MySQL Glossary.For a forum dedicated to the
InnoDBstorage engine, see MySQL Forums::InnoDB.InnoDBis published under the same GNU GPL License Version 2 (of June 1991) as MySQL. For more information on MySQL licensing, see http://www.mysql.com/company/legal/licensing/.