Can you please recommend me the ORM that meets requirements in the title?
The standard in the industry is Hibernate of course, but it's so great and I am not sure I can master it in days. Or can I?
It's preferred to configure it via annotations, not XML (writing XML by hand is quite boring, isn't it?).
Actually, all I need is just to conveniently issue CRUD queries. Probably, I could do with simple JDBC and classes, but project can eventually grow and that means even more tedious work should be done again and again. Don't want to do anything so boring as writing same CRUD again and again ;)
Fast means at least not times slower than others because it's going to power server, that will coordinate some distributed calculations and thousands of PCs are going to hit it per minute may be.
Simple-to-learn means simple first-step tutorial for it does not go over 5 pages of text and does not go into something like ObjectDispatcherizationStrategyMubleHuble every now and again ;)
I think simple CRUD is doable with Hibernate in days, except for the complexities introduced by 1:m and m:n relationships, lazy loading, open sessions for transactions, etc.
This assumes that you've got a solid object design to map to. If you don't, you're missing the "O" in ORM.
I think iBatis can be a nice intermediate step between JDBC and full-blown ORM. Check it out.