@mrz1
2018-02-08T08:28:04.000000Z
字数 1459
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笔记
事物四大特性：ACID（原子性 一致性 隔离性 持久性）详解？
命令：
SHOW ENGINES; #查看所支持的数据引擎 表格显示MariaDB| [(none)]> SHOW ENGINES\G # 列表显示
| Feature | MyISAM | Memory | InnoDB | Archive | NDB |
|---|---|---|---|---|---|
| Storage limits | 256TB | RAM | 64TB | None | 384EB |
| Transactions | No | No | Yes | No | Yes |
| Locking granularity | Table | Table | Row | Row | Row |
| MVCC | No | No | Yes | No | No |
| Geospatial data type support | Yes | No | Yes | Yes | Yes |
| Geospatial indexing support | Yes | No | Yes[a] | No | No |
| B-tree indexes | Yes | Yes | Yes | No | No |
| T-tree indexes | No | No | No | No | Yes |
| Hash indexes | No | Yes | No[b] | No | Yes |
| Full-text search indexes | Yes | No | Yes[c] | No | No |
| Clustered indexes | No | No | Yes | No | No |
| Data caches | No | N/A | Yes | No | Yes |
| Index caches | Yes | N/A | Yes | No | Yes |
| Compressed data | Yes[d] | No | Yes | Yes | No |
| Encrypted data[e] | Yes | Yes | Yes | Yes | Yes |
| Cluster database support | No | No | No | No | Yes |
| Replication support[f] | Yes | Limited[g] | Yes | Yes | Yes |
| Foreign key support | No | No | Yes | No | Yes[h] |
| Backup / point-in-time recovery[i] | Yes | Yes | Yes | Yes | Yes |
| Query cache support | Yes | Yes | Yes | Yes | Yes |
| Update statistics for data dictionary | Yes | Yes | Yes | Yes | Yes |
[a] InnoDB support for geospatial indexing is available in MySQL 5.7 and later.
[b] InnoDB utilizes hash indexes internally for its Adaptive Hash Index feature.
[c] InnoDB support for FULLTEXT indexes is available in MySQL 5.6 and later.
[d] Compressed MyISAM tables are supported only when using the compressed row format. Tables using the compressed row format with MyISAM are read only.
[e] Implemented in the server (via encryption functions). Data-at-rest tablespace encryption is available in MySQL 5.7 and later.
[f] Implemented in the server, rather than in the storage engine.
[g] See the discussion later in this section.
[h] Support for foreign keys is available in MySQL Cluster NDB 7.3 and later.
[i] Implemented in the server, rather than in the storage engine.