MariaDB与MySQL——特性比较

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更多的存储引擎

　　除了提供标准的MyISAM、BLACKHOLE、CSV、MEMORY、ARCHIVE和MERGE引擎外，在MariaDB源码与二进制包中还提供下列存储引擎：

• Aria
• XtraDB （与InnoDB对等替换）
• PBXT（在MariaDB 5.1、MariaDB 5.2与 MariaDB 5.3提供，MariaDB 5.5己不提供了）
• FederatedX （与Federated对等替换）
• OQGRAPH （在MariaDB 5.1、MariaDB 5.2与 MariaDB 5.3提供，MariaDB 5.5己不提供了） [size=0.6em]—5.2版添加
• SphinxSE [size=0.6em]—5.2版添加
• IBMDB2I.　Oracle公司从MySQL 5.1.55移除该引擎，MariaDB将在代码中保留其至版本5.5。
• TokuDBMariaDB 5.5与MariaDB 10.0
• Cassandra　MariaDB 10.0
  • 我们正忙于给MariaDB添加NoSQL存储引擎。
    
• CONNECT　MariaDB 10.0
• SEQUENCE 　 MariaDB 10.0
• Spider　MariaDB 10.0
  

速度提升

• 在MariaDB 5.3中进行了大量的优化提升，子查询真正可用了！完整的列表及与的比较请点击此处，性能指标请在此处查看。
• Faster and safer replication: Group commit for the binary log. This makes many setups that uses replication and lot's of updates more than 2x times faster.
• Improvements for Innodb asynchronous IO subsystem on Windows.
• Indexes for the MEMORY(HEAP) engine are faster. According to a simple test, 24% faster on INSERT for integer index and 60% faster for index on a CHAR(20) column.
• CHECKSUM TABLE is faster.
• We improved the performance of character set conversions (and removed conversions when they were not really needed). Overall speed improvement is 1-5 % (according to sql-bench) but can be higher for big results sets with all characters between 0x00-0x7f.
• Pool of Threads in MariaDB 5.1 and even better in MariaDB 5.5. This allows MariaDB to run with 200,000+ connections and with a notable speed improvement when using many connections.
• There are some improvements to the DBUG code to make its execution faster when debug is compiled in but not used.
• Our use of the Aria storage engine enables faster complex queries (queries which normally use disk-based temporary tables). The Aria storage engine is used for internal temporary tables, which should give a speedup when doing complex selects. Aria is usually faster for temporary tables when compared to MyISAM because Aria caches row data in memory and normally doesn't have to write the temporary rows to disk.
• The test suite has been extended and now runs much faster than before, even though it tests more things.
  

扩展&新特性

我们为MariaDB添加了很多新特性，假如一个补丁或特性是涉及可用性、安全与稳定性——我们会积极地将其添加到MariaDB中。特别值得一提如下：

• Microseconds in MariaDB [size=0.6em]— new in 5.3
• Microsecond Precision in Processlist
• Table Elimination
• Virtual Columns [size=0.6em]— new in 5.2
• Extended User Statistics [size=0.6em]— new in 5.2
• Segmented Key Cache for MyISAM [size=0.6em]— new in 5.2
• KILL all queries for a user [size=0.6em]— new in 5.3
• Pluggable Authentication [size=0.6em]— new in 5.2
• Storage-engine-specific CREATE TABLE [size=0.6em]— new in 5.2
• Enhancements to INFORMATION SCHEMA.PLUGINS table [size=0.6em]— new in 5.2
• Group commit for the binary log. This makes replication notably faster![size=0.6em] — new in 5.3
• Added --rewrite-db mysqlbinlog option to change the used database [size=0.6em]— new in 5.2
• Progress reporting for ALTER TABLE and LOAD DATA INFILE. [size=0.6em]— new in 5.3
• Faster joins and subqueries. [size=0.6em]— new in 5.3
• HandlerSocket and faster HANDLER calls. [size=0.6em]— new in 5.3
• Dynamic Columns support. [size=0.6em]— new in 5.3
• GIS Functionality[size=0.6em] — new in 5.3
• Multi-source replication. [size=0.6em]— new in 10.0
• SHOW EXPLAIN gives the EXPLAIN plan for a query running in another thread.[size=0.6em] — new in 10.0
  

For a full list, please see features for each release

更充分的测试

• More tests in the test suite.
• Bugs in tests fixed.
• Test builds with different configure options to get better feature testing.
• Remove invalid tests. (e.g. don't test feature ''X'' if that feature is not in the tested build)
  

更少的警告与缺陷

• Bugs are bad. Fix as many bugs as possible and try to not introduce new ones.
• Compiler warnings are also bad. Eliminate as many compiler warnings as possible.
  

真正开源

• All code in MariaDB is released under GPL, LPGL or BSD. MariaDB does not have closed source modules like the ones that can be found in MySQL Enterprise Edition. In fact, all the closed source features in MySQL 5.5 Enterprise Edition are found in the MariaDB open source version.
• MariaDB includes test cases for all fixed bugs. Oracle doesn't provide test cases for new bugs fixed in MySQL 5.5.
• All bugs and development plans are public.
• MariaDB is developed by the community in true open source spirit.