Marc Schoechlin wrote:
Gert van der Kooij <ge**@invalid.n l> schrieb: I'm trying to port a PostgreSQL application to DB2 LUW 8.2.2 (Win32, if
Why are you doing that ? :-)
This no flame-question, I'm really interested which in which aspects
DB2 is the the better choice if you already have such a powerful DBMS.
Mark,
Postgresql is a cool little database. My shop tries to use it in place
of mysql whenever an open source database is used (usually for an
open-source application). It's prefered over mysql because it is so
much more mature: views aren't in a development release like they are
in mysql, they've been there for years, the optimizer is more than six
lines of code, etc, etc.
However, we still migrate databases from postgresql to db2 all the
time. The reasons include:
- minimize labor costs and improve admin/developer effectiveness:
- focus developers on a single database - which helps them in
their training on advanced sql, performance tuning, locking,
etc
- focus admins on a single database - which again helps with
all developer eduction; plus backups, auditing, configuration,
etc.
- enables greater sharing of resources as well as some dba
outsourcing
- handle large data volumes
- postgresql has no query parallelism capability to help with table
scans
- postgresql has no range partitioning to minimize impact of table
scans (tho union-all views or the like are in the works)
- postgresql has no hash partitioning to spread query across more
cpus
- postgresql has very primitive memory tuning (just one buffer
pool)
So, we end up saving quite a lot in labor, are able to outsource some
of our admin to a db2 group, and are able to get better performance out
of the same hardware with db2. The only downside is the licensing cost
- but there are many low-cost db2 licenses available to reduce this
impact anyway.
buck
