Monday, March 27, 2006

Partition and Scanning

If a query does a SELECT the optimizer will discover which partitions
that has to be scanned. In 5.1 these scans will still be made
sequentially on one partition at a time. However only those partitions
actually touched will be scanned which can improve performance on
certain queries by a magnitude.

The aim is to support parallel scan in a future release as it is to
support parallel sort on the first table selected by the optimizer.
This is an important long-term goal of partitioning to open up the
MySQL architecture for many performance improvements on
handling large data sizes. In 5.1 we have achieved quite a few of
those goals but expect to see more goals achieved as new versions
of MySQL hits the street burning :)

3 comments:

Anonymous said...

hello,Mikael
Hon does Mysql NDB cluster 5.0.27 Support Partition and parallel Scanning in full table scan and order index scan? Does it scan all node groups or nodes simultaneously?

thanks!
my name:zhibo.fu

please reply to email:fzb0717@sohu.com

David said...

Hi Mikael,

Any news on when the support for parallel scan will be included. We are currently about to choose whether to give up MySQL and use Oracle Enterprise edition instead because they support this feature. You really have a great product so I would hate to leave you.

Regards,

David

David said...

Please reply to mrdavidandersen@gmail.com