Bug #74638 5.7.5 data dictionary installation and thoughts
Submitted: 30 Oct 2014 16:24 Modified: 31 Oct 2014 9:25
Reporter: Simon Mudd (OCA) Email Updates:
Status: Verified Impact on me:
None 
Category:MySQL Server: Data Dictionary Severity:S3 (Non-critical)
Version:5.7.5 DD OS:Linux
Assigned to: CPU Architecture:Any

[30 Oct 2014 16:24] Simon Mudd
Description:
I saw Morgan's post: http://www.tocker.ca/2014/10/15/experimenting-with-the-new-data-dictionary-labs-release.ht... but it didn't quite work for me.

I had a similar issue to him and needed to explicitly state the  --lc-messages-dir=/usr/local/mysql/share when running mysql_install_db. His post doesn't mention this.

Also as he mentions it helps a lot of the output of the command being run is shown to the user, so please ensure that this is kept and shown and not hidden. Perhaps mysqld/mysql_install_db should be a bit smarter as I had set this in /etc/my.cnf but it seemed to ignore the setting.

How to repeat:
see above.

Suggested fix:
Better reporting of errors.
Better documentation of other settings that may need to be set.

I usually use an rpm setup so already have existing /etc/my.cnf files and want to use these adjusting with the minimal settings I've been using, so an existing installed rpm files may interfere with the 5.7.5 DD installation unless I'm careful.

One thing as a general comment I miss for these lab feature is it is not clear exactly what feedback you are after and how you want us to provide this.  If we provide details then bugs.mysql.com doesn't seem the best place to provide site specific info and testing etc so providing information on what you want would be useful.

I did some simple tests by loading in about 6,000 table definitions from a live server (in 300 dbs) and found that 5.7.5 DD was slower than the original 5.6 box and I'd assume the data would be cached in RAM and so we'd see better performance. That's doing simple things like:
SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES or
SELECT TABLE_SCHEMA, COUNT(*) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA LIKE 'XXXXX%' GROUP BY TABLE_SCHEMA.

With something like DD releases having a way to convert to and from a normal release would make it much easier to test real servers converting them and making them live again. I assume that work is in place to do this conversion but please consider going both ways so even if initially DD is slow we can back out after testing and use a normal 5.7 binary more easily.
[31 Oct 2014 9:25] MySQL Verification Team
Hello Simon,

Thank you for the report and feedback.

Thanks,
Umesh
[31 Oct 2014 9:27] MySQL Verification Team
Also, please take a look at these reports which are related to new mysql_install_db

http://bugs.mysql.com/bug.php?id=73845 
http://bugs.mysql.com/bug.php?id=74469
[31 Oct 2014 11:17] Ståle Deraas
Thanks for your feedback. Our intention with the this labs release is to show this work to the community at an early stage, and as such show the direction we are taking.