PostgreSQL vs MySQL?

[Rasjid Wilcox]

Quick views on PostgreSQL vs MySQL (or even InterBase?)

I looking at teaching myself Java with the aim of building some cross 
platform database products.  My prefered platform is Linux, but I'd like to 
make things that work okay in the Windows world too (for strategic reasons 
only ;-).

MySQL has a reputation for being fast, but somewhat feature limited.  I note 
that its foreign key support is fairly recent and is still missing some 
features as far as I can tell.

PostgreSQL has a reputation for being slower (probably not a big issue for 
the type of apps I'm thinging of) but has a better feature set.

I didn't even know that there was an open source version of InterBase until I 
today.  It looks like a 'Mozilla' type of open source licence. 
Anyone got views on just how committed Borland is to open source?  (They have 
done Kylix as well...)

I guess my main issues are features (foreign key support would be good, and 
replication might be useful too) and portability.  In particular I was hoping 
for Windows 98 support (although I guess this will get less important over 
time as more people move to Linux - oh, and Windows XP etc rather than Win98 
I guess, but why anyone would do that is beyond me ;-).

I initially thought it was more portable than PostgreSQL, as I know it is 
Cygwin based and only claims to support NT etc.  However, I now notice that 
MySQL on Windows is also Cygwin based.  Anyone with any experience in how 
they compare running on Windows 98?  (Does PostgreSQL actually run on Windows 
98?)

Based on my reading of the various websites, InterBase is looking like the 
best option, with PostgreSQL second and MySQL third.  But I'd like to hear 
from people that have actually used them (on any platform).

Cheers,

Rasjid.