Jonas in the Cluster team reported on his work on executing
joins in the NDB kernel for MySQL Cluster here.
This is a very interesting work we have in progress at
MySQL.
We are working on an extension of the Storage Engine API
where the MySQL Server will present an Abstract Query Tree
to the Storage Engine. The Storage Engine can then decide
to
execute the query on his own or decide that the MySQL
Server
should execute it in the classic manner. In the first
prototype
the optimisation will be done as usual and only after the
optimisation phase will we present the join to the storage
engine. However the specification also covers work on
integrating this with the optimiser and also enabling the
possibility for the storage engine to execute parts of the
query and not the entire one. The specification …
I had a very interesting conversation on the phone with
Jonas
Oreland today (he also blogged about it on his blog at
http://jonasoreland.blogspot.com).
There is a lot of interesting features coming up in MySQL
Cluster
version 6.4. Online Add Node is one of those, which can be
done
without any downtime and even with almost no additional
memory
needed other than the memory in the new machines added into
the
cluster. This is a feature I started thinking almost 10 years
ago
so it's nice to see the fourth version of the solution actually
be
implemented and it's a really neat solution to the problem,
definitely fitting the word innovative.
The next interesting feature is to use a more efficient
protocol
for handling large operations towards the data nodes. This makes
it
use less bits …
The newest development in the partitioning code
is WL#4571.
This new feature makes it possible to tie a
partition using MyISAM to a specific cache index.
The syntax for how to do is available in the
above worklog entry.
We found this feature to be useful for enabling
higher performance of parallel ALTER TABLE
(WL#2550). When adding
a primary key to a MyISAM table the key cache in
MyISAM limited scalability of Parallel ALTER TABLE
severely, so adding several key caches, essentially
one per partition we can ensure that the ALTER TABLE
can be fully parallelised (all other ALTER TABLE
on MyISAM already scales perfectly).
We also have some ideas on how to solve the base
…