InnoDBConcepts and Architecture
InnoDBPerformance Tuning and Troubleshooting
InnoDBFeatures for Flexibility, Ease of Use and Reliability
InnoDBStartup Options and System Variables
InnoDB is a general-purpose storage engine that
balances high reliability and high performance. In MySQL
5.6, issuing the
TABLE statement with no
Key advantages of
InnoDB tables include:
InnoDB tables arrange your data on disk to
optimize queries based on
You can freely mix
InnoDB tables with tables
from other MySQL storage engines, even within the same
statement. For example, you can use a
join operation to combine data
tables in a single query.
InnoDB offers significant new
features over MySQL 5.1 and earlier. These features focus on
performance and scalability, reliability, flexibility, and
Fast index creation: add or drop indexes without copying the data.
Data compression: shrink tables, to significantly reduce storage and I/O.
More efficient storage for
large column values: fully off-page storage of long
Barracuda file format: enables new features while protecting upward and downward compatibility
tables: information about compression and locking
Performance and scalability enhancements: includes features such as multiple background I/O threads, multiple buffer pools, and group commit.
Other changes: for flexibility, ease of use and reliability.
InnoDB Storage Engine
|Storage limits||64TB||Transactions||Yes||Locking granularity||Row|
|MVCC||Yes||Geospatial data type support||Yes||Geospatial indexing support||No|
|B-tree indexes||Yes||T-tree indexes||No||Hash indexes||No[a]|
|Full-text search indexes||Yes[b]||Clustered indexes||Yes||Data caches||Yes|
|Index caches||Yes||Compressed data||Yes[c]||Encrypted data[d]||Yes|
|Cluster database support||No||Replication support[e]||Yes||Foreign key support||Yes|
|Backup / point-in-time recovery[f]||Yes||Query cache support||Yes||Update statistics for data dictionary||Yes|
[a] InnoDB utilizes hash indexes internally for its Adaptive Hash Index feature.
[b] InnoDB support for FULLTEXT indexes is available in MySQL 5.6.4 and higher.
[c] Compressed InnoDB tables require the InnoDB Barracuda file format.
[d] Implemented in the server (via encryption functions), rather than in the storage engine.
[e] Implemented in the server, rather than in the storage engine.
[f] Implemented in the server, rather than in the storage engine.
InnoDB has been designed for maximum performance
when processing large data volumes. Its CPU efficiency is probably
not matched by any other disk-based relational database engine.
InnoDB storage engine maintains its own
buffer pool for caching data
and indexes in main memory. By default, with the
enabled, each new
InnoDB table and its associated
indexes are stored in a separate file. When the
innodb_file_per_table option is
InnoDB stores all its tables and
indexes in the single system
tablespace, which may consist of several files (or raw disk
InnoDB tables can handle large
quantities of data, even on operating systems where file size is
limited to 2GB.
InnoDB is 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/.