A much awaited release from the MariaDB project is now stable (GA) – MariaDB Galera Cluster 10.0.12. This is a complete merge of MariaDB 10.0.12 and Galera Cluster, with additional features and bug fixes. This gives you the entire power of Galera Cluster as well as the benefits of all the MariaDB 10 features.
This is the fourth release in the 10.0 Galera Cluster series, and for more changes, please review the changelog and release notes. What are you waiting for, download it now!
Update: In this release there is known regression on certain foreign key use cases using multi-part multi-byte foreign keys. Insert to child table causes server crash. For example the following can cause a server crash:
create table p(v varchar(10), i int, primary key(v,i)) engine=innodb character set = utf8;
create table c(k int primary key, v varchar(10), i int, foreign key(v,i) references p(v,i)) engine=innodb character set = utf8;
insert into p values ('a»a',1); insert into c values (1, 'a»a',1);
MariaDB 10 is nearing GA, and it makes sense to make sure that the test suite from MySQL 5.6 is merged into MariaDB 10. Svoj is doing a lot of this work, and then we like to look at features, especially ones that are deprecated upstream. We don’t do that on blogs, but on the maria-developers mailing list.
I bring to your attention: Intermediate status for test cases merge. We see that INSERT DELAYED and SHOW PROFILE for example are deprecated in MySQL 5.6. The only way for feedback to the MySQL team seems to be comments on Morgan’s blog. However with MariaDB, especially with the feedback plugin enabled, we have an additional layer of information besides just comments on a blog or mailing list.
We see from the features being used, INSERT DELAYED and SHOW PROFILE are still being used. The rest of the thread is an interesting read, as for example we should probably follow 5.6 in making NO_ENGINE_SUBSTITUTION to be the default. Also if you’re interested in the reason behind YEAR(2) existing, there is reasoning to why it exists.
The list continues. If you’re interested in MariaDB development, please ensure that you’re subscribed to the maria-developers mailing list, and if you’re a user, please consider enabling the user feedback plugin.
First, congratulations Oracle on the GA of MySQL 5.6! Well done!
In this post I walkthrough the features of the first two alpha versions of MariaDB 10.0. The first, 10.0.0-alpha, which was made available in November, and 10.0.1-alpha that saw daylight yesterday. I will go through the features by placing them in the following categories:
- MariaDB 10.0-only Features (features that aren’t in MySQL 5.6)
- MariaDB 10.0 Merged Features (features merged from MySQL 5.6)
- MariaDB 10.0 Reimplemented Features (features reimplemented from features in MySQL 5.6)
- MariaDB 5.x Features now in MySQL 5.6 (features introduced in earlier MariaDB versions which have now been introduced in MySQL 5.6)
- MariaDB 5.x Features Backported from MySQL 5.6 (features introduced in earlier MariaDB versions which were backports of features from MySQL 5.6 development versions)
Some of the features will have links to the MySQL manual for the documentation Oracle has made available on the feature.
MariaDB 10.0-only Features
Features in this section are unique to MariaDB 10.0 and aren’t found in MySQL 5.6.
Available since 10.0.0
- Multi-source replication (MDEV-253)
- Multi-source replication is a longtime wish of many users. In scenarios where you partition your data over many masters you can then replicate the data from all masters onto one slave. Typical use cases are:
- Data partitioned over many masters can be pulled together onto one slave for analytical queries
- Many masters can replicate to the same slave and a complete backup can be done on the slave
- Newer hardware usually provides more performance. Usually all hardware isn’t upgraded at once and multi-source can be used for replicating many masters to a powerful new slave.
- Original code from Taobao
- Even faster Group Commit
- Further enhancements have been made to group commit. A couple of blog posts about the improvements by the developer, Kristian Nielsen, can be found here.
- SHOW EXPLAIN
- Get the query plan of a running statement.
Now available in 10.0.1
- Cassandra Storage Engine
- An integration of the NoSQL database Apache Cassandra. Cassandra is seen as a storage engine to MariaDB. The integration enables:
- Combining data from Cassandra and MariaDB
- Reading and writing to Cassandra from MariaDB. SQL’s SELECT, INSERT, UPDATE and DELETE all work.
- Engine independent statistics
- Optimizer statistics is the collection of data that describe more details about the database and the objects in the database.
- Statistics are now provided separately from storage engines. Before, statistics were supplied by the storage engines themselves and the quality of the statistics were usually quite poor. Also, since before this they were provided through the storage engine interface, a lot of restrictions were put on them.
- These statistics are used by the query optimizer to choose the best execution plan for each SQL statement. Better statistics results in better execution plans and end users will experience faster results in general.
- Statistics are collected also for non-indexed columns. InnoDB’s statistics, for example, were previously only for indexes.
- Improved Dynamic Columns
- Dynamic Columns has been in MariaDB for a while already. This feature allows you to store a different set of columns for every row in a table. In that manner Dynamic Columns can be called NoSQL-like.
- Since MariaDB introduced Dynamic Columns there has been user feedback and research going on to improve it further. Dynamic Columns has some new capabilities that now are in mainline MariaDB:
- Database interoperability: It’s pretty rare that companies use only a single type of database and even critical business systems are often built on several different types of databases. Usually the data from those different databases is combined in an upper application level. MariaDB introduces the possibility of doing this at a low level inside the MariaDB database. The first implementation of this is integration with Cassandra. With Dynamic Columns and the Cassandra Storage Engine you can now combine data residing in Cassandra with data inside MariaDB and this is done through normal looking queries on the MariaDB side.
- Data interchange: JSON has become a very popular standard for data interchange. In Dynamic Columns one can now request a row in JSON format.
- Per thread memory usage (MDEV-4011)
- Based on a patch by Taobao, INFORMATION_SCHEMA and SHOW STATUS enables the analysis of thread specific memory usage
- Faster ALTER TABLE with UNIQUE key (MDEV-539)
- Significant speed up of ALTER TABLE with unique keys (for Aria and MyISAM storage engines)
MariaDB 10.0 Merged Features
Features listed in this category have been directly merged from MySQL 5.6.
Already available since MariaDB 10.0.0
- InnoDB and Performance Schema
- Most InnoDB enhancements, but some, for example InnoDB’s fulltext capabilities, will come in an upcoming version of 10.0.
MySQL Manual: InnoDB.
- The full new performance schema with all the new event filtering, instrumentation, and other goodies.
MySQL Manual: Performance Schema
- ORDER BY … LIMIT -optimization
- A useful optimization for showing only a few rows of a bigger resultset.
MySQL Manual:Limit Optimization
Now added in 10.0.1
- Plugin-load-add (MDEV-3860)
- Used to avoid specifying a large set of plugins in a single long argument
MariaDB 10.0 Reimplemented Features
These features are re-implementations of the corresponding functionality in MySQL 5.6. In future versions of MariaDB 10.0 there will be a few more features in this category. I’ll cover them in a future blog post.
- Add full support for auto-initialized/updated timestamp and datetime
MariaDB 5.x Features now in MySQL 5.6
Earlier MariaDB 5.x versions included features that have now been introduced in MySQL 5.6. It should be noted that the corresponding features in MySQL 5.6 haven’t been merged from MariaDB. Oracle has re-implemented them.
MariaDB 5.x Features Backported from MySQL 5.6
These features were merged from MySQL 5.6’s development trees to MariaDB, where they were then hardened for production use.
- Binlog checksums, were introduced in MariaDB 5.3. It is backport of the corresponding feature in MySQL 5.6.
As you can see above there are quite many features in MariaDB 10.0 already, but more is coming. Stay tuned for an update on features going into MariaDB 10.0.2.