Ivan's Blog

This is a shortlist of the questions raised during the webinar MySQL Enterprise Performance and Benchmarking that I presented the 9th of April.

The slides are available here.
The full recording of the webinar is available here.

Questions and Answers:

Q from Chris: Are you able to monitor all versions (non-Enterprise and 4.1) with MySQL enterprise monitor ?
A: Yes, you can, but some advisors will not work with versions prior to 5.0.

Q from Chris: If for example I have a couple of Enterprise systems but also some non-enterprise systems (we will be migrating over time) then would we be able to use the monitor (which we will have access to with the enterprise license) to monitor our legacy servers?
A: Yes, you can certainly do that. You can purchase the subscriptions, but you do not need to install or migrate to the certified binaries.

Q from Zenon: Where can I find details of Enterpise Subscription costs?
A: All the costs and the information are here: https://shop.mysql.com/enterprise/

Q from Douglas: if you buy the platinum licence for one server which comes with the performance advisor, will it monitor a servers performance which only has the gold licence?
A: You will be able to collect all the information, but the advisors associated to the platinum subscription will not work.

Q from Wojtek: Can I know the database usage per database user?
A: Not with the standard advisors. You need need to create your own advisor to present this information.

Q from Ole: Will we see any improvements to the optimizer in 5.1? Especially in handling subqueries and views?
A: With 5.1 we have improvements in the efficiency of the fulltext indexing. You have to wait 6.0 to see even more improvements, for example with subqueries

Q from Zenon: Is query cache just for static data? How does it handle data that has changed between the same query calls?
A: Query cache is invalidated by any write operation applied to one of the tables that are part of the stored query. It is very efficient if data don't change very often.

Q from Ronny: Novell ships the Enterprise license of mySQL with NetWare, can I monitor it with a platinum license to get the advisor?
A: Unfortunately Netware is not one of the supported platforms - there isn't an agent available for Netware.

Q from Rotem: I really want to use partitions - When will 5.1 become GA? Is it considered safe to use it now before it becomes GA?
A: 5.1 is now release candidate, we plan to deliver it GA by the end of Q2 2008. There are still some issues associated to partitioning that may or may not affect you. You should check the list of issues and bugs here: http://bugs.mysql.com

Q from Eleonora: Hi, I have a doubt about the MEMORY storage engine. Is it able to gaurantee no loss of data? What happens if the server dies before writing data to disk?
A: the MEMORY storage engine does not write any data to disk, therefore if you shutdown the server of in case of fault of the mysql daemon, the data in the MEMORY tables is lost. You may setup a backup to disk using a scheduled job, but this will not prevent some loss of data.

Q from Michael: Is it possible to tune parameters for different connections to the same MySQL server?
A: Yes, there are parameters that are session based, therefore they will affect only a specific session.