Re: Oracle / PostgreSQL comparison...

On 06/23/2011 10:28 PM, Stephen Frost wrote:
> Next, PG doesn't even use the same basic technology as Oracle regarding
> how transaction isolation and versioning works. Oracle using rollback
> segments to store 'old' rows in, while PG uses a Multi-Version
> Concurrency Control (MVCC) system. They're fundamentally different
> things, so the notion that PG is somehow a 'reverse engineered' Oracle
> is complete bunk.

I stole some inspiration from this comment for my own response, which I
just posted to the site. I'll save a copy here in case the author
becomes so embarrassed by his mistakes he deletes it:

The idea that PostgreSQL is reverse engineered from Oracle is
ridiculous. Just a look at the vast differences in the MVCC
implementation of the two; Oracle's redo logs vs. PostgreSQL WAL are
completely difference designs.

As for there being no unique features in PostgreSQL, that's completely
wrong too. A good example is how deep the transactional DDL
<http://wiki.postgresql.org/wiki/Transactional_DDL_in_PostgreSQL:_A_Competitive_Analysis>
features go--Oracle has started to catch up recently, but PostgreSQL
still has a lead there. The ability extend the type system and indexes
with your own custom items are also better in PostgreSQL than any other
database. This is why the PostGIS add-on (built using the type extension
facility) is busy displacing installations of the weaker Oracle Spatial
at installations all over the world right now.

As for support, there are half a dozen companies in the world you can
buy PostgreSQL support from at a fraction of the rate Oracle charges for
it. I routinely fix bugs in the database itself within hours of report
for my customers, as part of a service contract, which is an option on
top of the free community support. Because PostgreSQL is open-source,
there are multiple vendors available who provide this service. With
Oracle as a closed source product, there can only be one who is capable
of offering this quality of support. And that single source vendor has
quite a history of squeezing as many dollars out of its customers as its
can. Since there is choice among PostgreSQL support companies, you'll
never get into that position with it.

--
Greg Smith 2ndQuadrant US greg(at)2ndQuadrant(dot)com Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.us
"PostgreSQL 9.0 High Performance": http://www.2ndQuadrant.com/books