PostgreSQL is an Object Relational DataBase? Management System.
It is Free Software available from http://www.postgresql.org
Usually PostgreSQL's default configuration is not optimal, but works even on small machines.
To achieve better performance, you'll want to modify some settings. For example, here's what I've put in my
postgresql.conf file on my Dual-PIII 1Ghz machine with 1 Gb RAM with PostgreSQL 7.4.x :
IMPORTANT : Don't try to modify these settings if you don't understand what they do. Please give a look at http://www.varlena.com/GeneralBits/Tidbits/perf.html and http://www.postgresql.org/files/documentation/books/aw_pgsql/hw_performance/ for more details.
Finally, if you've got several thousand users which you plan to delete in a single shot, increasing the
max_expr_depth value (PostgreSQL 7.x) or the
max_stack_depth value (with 8.x) may be required.