OK, the review is kinda lame, but the comments on this Slashdot book review
are pretty good, many of them really funny...but oh so true. I won't go into my opinions of MySQL
...ooops, too late.
And I just found this link for VistaDB, version 2.0 of which was recently released. I haven't heard of it before, anyone try it yet? Gotta admit, some of the praise ("I...cannot stop being thrilled with the speed") sounds pretty corny though. Don't know how it stacks up to REL, but at least it has PROPERLY FUNCTIONING foreign key constraints.
Lastly, if you do have to work with different flavors of SQL, or just want to see how the other side(s) live, SQL In a Nutshell from O'Reilly is a really good reference that covers every little nuance of all the SQL flavors out there: Oracle, SQL Server, MySQL, DB2, PostGreSQL, and some Sybase too. Kevin Kline is the author, and also President of PASS. He was kind enough to hand out a number of autographed copies at this year's PASS Community Summit, and is a terrific speaker/presenter as well. (probably gives himself the really choice presentations)