I have been working through Getting Started with Grails, Second Edition by Scott Davis and Jason Rudolph.
Throughout the process of working through their Racetrack sample application, I have been switching between MongoDB 2.0.6 and MySQL 5.5.25.
In the process, I have hit some bumps in the road regarding MongoDB Issues with Grails Scaffolding that do not occur in MySQL.
I posted these on StackOverflow and mentioned in LinkedIn discussions. This has led me down the path of going so far as to trying to download a tag from GitHub for newer builds of the MongoDB Plugin for Grails (as of today 2012-08-22, 1.0.0.GA is the latest official release for this plug-in).
I've also learned a lot about MySQL in the process of setting it up, securing it on Fedora 17.
Neat things I've learned:
- As of MySQL 5.5.5, InnoDB has replaced MyISAM as the default engine
- There is a bug with Hibernate 3.6.1 and MySQL when using MyISAM. On the Hibernate JIRA: HHH-5988 - HBM2DLL creates invalid Create Table statement on MySQL 5.5.x because keyword *TYPE* is forbidden now