Google Summer of Code 2014
We participated in Google Summer of Code 2014. MariaDB and the MariaDB Foundation believe we are making a better database that remains a drop-in replacement to MySQL. We also work on making LGPL connectors (currently in C, Java, C++ in development) and on MariaDB Galera Cluster, which allows you to scale your reads & writes.
Contents
- Where to start
- LDAP authentication plugin
- Self-Tuning Optimizer
- Port InnoDB memcached interface to MariaDB
- GIS enhancements to MariaDB
- User defined events
- Indexes for BLOBs (in MyISAM and Aria)
- CREATE OR REPLACE, CREATE IF NOT EXISTS, and DROP IF EXISTS
- Statistically optimize mysql-test runs by running less tests
- Improved temporary tables
- Table UDFs
- GTID support in mysqlbinlog
- See Also
Where to start
Please join us at irc.freenode.net
at #maria to mingle with the community. Or subscribe to [email protected]. Or both.
Please keep in mind that in April we travel a lot (conferences, busy time), so if you have a question and nobody on IRC answers — do not feel disappointed, ask in an email to [email protected]. Asking on the mailing list means others benefit from your Q&A too!
LDAP authentication plugin
We would like the authentication system to be able to authenticate against a LDAP Directory Server.
Skills: C, working knowledge of LDAP
Mentor: Sergei Golubchik
Self-Tuning Optimizer
this project is taken
One of the reasons for bad query plans is inadequate cost estimation of individual operations. A cost of reading a row in one engine might be a lot higher than in some other, but the optimizer cannot know it. Also, it uses hard-coded constants, assuming, for example, that evaluating a WHERE clause is 5 times cheaper than reading a row from a table.
Obviously, some kind of calibration procedure is needed to get these cost estimates to be relatively correct. It is not easy, because the estimates depend on the actual hardware where MariaDB is run (a cost of a row read is different on HD and SSD), and also — somewhat — on the application.
A simple and low-maintenance solution would be to use self-tuning cost coefficients. They measure the timing and adjust automatically to the configuration where MariaDB is run.
See MDEV-350.
Skills: C/C++
Mentor: Sergei Golubchik
Port InnoDB memcached interface to MariaDB
MySQL 5.6 has a memcached plugin to InnoDB. MySQL 5.7 has improved performance of this. The task would be to port this to run against MariaDB, and make it work against XtraDB/InnoDB for the 10.1 series of MariaDB.
See MDEV-4674 for more.
Skills: C/C++
Mentor: Colin Charles
GIS enhancements to MariaDB
GIS enhancements for 10.1 that we want to work on include adding support for altitude (the third coordinate), as well as making sure we are fully OpenGIS compliant. MDEV-5813
Skills: C
Mentor: Holyfoot
User defined events
User defined events are supported on several other databases in different form and semantics. Events are used to signal a named event in the database. Applications can use named events instead of polling, which uses more resources.
See MDEV-5532 for more.
Skills: C/C++
Mentor: Jan Lindstrom, Sergei Golubchik
Indexes for BLOBs (in MyISAM and Aria)
MyISAM and Aria support special kinds of indexes that only store the hash of the data in the index tree. When two hashes match in the index, the engine compares actual row data to find whether the rows are identical. This is used in internal temporary tables that the optimizer creates to resolve SELECT DISTINCT
queries. Normal unique indexes cannot always be used here, because the select list can be very long or include very long strings.
This task is to provide a direct SQL interface to this feature and to allow users to create these indexes explicitly. This way we can have unique constraints for blobs and very longs strings.
Skills: C++
Mentor: Sergei Golubchik
CREATE OR REPLACE, CREATE IF NOT EXISTS, and DROP IF EXISTS
this project is taken
This task is to add support for OR REPLACE
and IF EXISTS
/ IF NOT EXISTS
to all CREATE
and DROP
variants for all objects (where it makes sense). MDEV-5359
Skills: C++
Mentor: Sergei Golubchik
Statistically optimize mysql-test runs by running less tests
this project is taken
This is a research not a coding task. See MDEV-5776
Skills: SQL, Perl/Python or other language of your choice, mathematical statistics
Mentor: Elena Stepanova, Sergei Golubchik
Improved temporary tables
It is a well-known and very old MySQL/MariaDB limitation that temporary tables can only be used once in any query; for example, one cannot join a temporary table to itself. This task is about removing this limitation. MDEV-5535
Skills: C++
Mentor: Sergei Golubchik
Table UDFs
Implement a new plugin type that adds support for table UDFs — loadable User-Defined Functions that return tables, not scalar values.
Skills: C++
Mentor: Sergei Golubchik
GTID support in mysqlbinlog
The mysqlbinlog
tool needs to understand global transaction ids. In particular, it should be possible to start and end the dump at the specified GTID. Both when reading binlog files and when connecting to a running server. See MDEV-4989.
If time permits, other client programs could be extended similarly, like mysqldump --master-data or the --sync-with-master command in mysqltest.
Skills: C++
Mentor:
See Also
- See also «GSoC 2014 tasks» list in Jira.