Relational databases are their for long time and going forward nothing seems to change that trend.
Object oriented database are now history and it seems that the idea was great but execution wasn’t. So we are pretty much goona live our life with RDBMS.
I was working in Computer graphics and we used to have 3D file formats like DWG ,DXN ,IGES etc and for couple of years i had absolutely no contact with databases.But as i am again working in JEE world and in this world DB’s are backbone of any application.
So how to be with current with this aspect of your programming world , well I’ll suggest http://www.databasecolumn.com/
And if you just want to hone up your Db skill’s than you can try these