postgresql or mysql

[gustavo halperin <ggh.develop@gmail.com>]

Hello

I'm starting to work with DB, and I have a doubt about if learn and use 
postgresql or mysql. From the links:
  http://linas.org/linux/db.html
  http://www-css.fnal.gov/dsg/external/freeware/mysql-vs-pgsql.htm
I understand that postgresql is better, but if  I'm right  why SQL looks 
more popular ???
Which DB you recommend like the best one ??


          Thank you,
              Gustavo Halperin