Now we would love to get your feedback on this new feature:
- Does what we have right now improve performance for you?
- Are there other types of JOINs we should support in order to improve performance in you application (currently only eq_ref is supported)?
- What application are you using?
There are some limitations currently:
- node failure handling of SPJ is not complete, so if a data node crash, there are side-effects.
- only eq_ref is supported - other JOINs are executed as normal.
- Don't put this in production.
- You must know how to build MySQL Cluster from source
- www.severalnines.com/config includes "7.1 SPJ Preview" (the scripts will compile and distribute the binaries for you) - just select "MySQL Cluster 7.1.3-SPJ" from the Cluster Version drop down.
- The source code (if you don't use severalnines/config) can be found here.
- Run a JOIN query:
mysql> set ndb_join_pushdown=0;
mysql> run join query
mysql> set ndb_join_pushdown=1; //ENABLES SPJ
mysql> run join query again
Did it help?
- Run EXPLAIN on the queries (especially if SPJ did not help)
- Send us the EXPLAINs of the queries where SPJ did not help!
- Let us know if this feature was helpful for your application.
and in any case please include
- What kind of speed up (or decrease) was observed
- What kind of cluster configuration/hw was used.
spj-feedback (at) sun (dot) com. Thank you!
Read more about SPJ:
- More details about SPJ is in Jonas' MySQL UC 2010 presentation.