在高性能MYSQL上还说默认MYISAM,其实要看那个版本,我现在的默认就是InnoDB,手册上是这么说的:
InnoDB
is a high-reliability and high-performance storage engine for MySQL. Starting with MySQL 5.5, it is the default MySQL storage engine. Key advantages of InnoDB include:
-
Its design follows the
ACID model, with
transactions featuring
commit,
rollback, and
crash-recovery capabilities to protect user data. -
Row-level
locking and Oracle-style
consistent reads increase multi-user concurrency and performance. -
InnoDB
tables arrange your data on disk to optimize common queries based on
primary keys. Each
InnoDB
table has a primary key index called the
clustered index that organizes the data to minimize I/O for primary key lookups. -
To maintain data integrity,
InnoDB
also supports
FOREIGN KEY
referential-integrity constraints. -
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 from
InnoDB
andMEMORY
tables in a single query.
To determine whether your server supports InnoDB
use the
SHOW ENGINES
statement.
Before MySQL 5.5.5,
is the default storage engine. (The default was changed to
MyISAM
InnoDB
in MySQL 5.5.5.) MyISAM
is based on the older (and no longer available)
ISAM
storage engine but has many useful extensions.
Table 13.10. MyISAM
Storage Engine Features
Storage limits | 256TB | Transactions | No | Locking granularity | Table |
MVCC | No | Geospatial data type support | Yes | Geospatial indexing support | Yes |
B-tree indexes | Yes | Hash indexes | No | Full-text search indexes | Yes |
Clustered indexes | No | Data caches | No | Index caches | Yes |
Compressed data | Yes[a] | Encrypted data[b] | Yes | Cluster database support | No |
Replication support[c] | Yes | Foreign key support | No | Backup / point-in-time recovery[d] | Yes |
Query cache support | Yes | Update statistics for data dictionary | Yes |