Re: PostgreSQL vs. MySQL vs. Oracle, 2005 report card

Tom Lane wrote:
> Scott Marlowe <smarlowe(at)g2switchworks(dot)com> writes:
>>On Wed, 2005-02-16 at 11:13, Ron Mayer wrote:
>>
>>>Fermilab did have contact information ("mail comments to:") at the
>...
> Right. The question is whether we can get them to update it.

I think so... as mentioned earlier in the thread, they did update
some of the answers saying "postgresql version 8 has this" already.

I just sent them an email with links to the postgresql docs for
each of the answers I know have been already addressed.
The email I sent them is attached below. Feel free to send them
corrections to my corrections. :)

-------- Original Message --------
Subject: Your database comparison page
Date: Wed, 16 Feb 2005 14:35:02 -0800
From: Ron Mayer [XXX]
To: css-dsg(at)fnal(dot)gov

On your database comparison page here:
http://www-css.fnal.gov/dsg/external/freeware/mysql-vs-pgsql.html
where you write "Mail comments to:css-dsg(at)fnal(dot)gov"

I think there are a few new updates in postgresql that you
might not have been aware of...

* Partial rollback of transaction:
...
Oracle8: Rollback to savepoint.
PostgreSQL:No.

Savepoints and Rollback to Savepoint have been added
to postgresql in version 8.
http://www.postgresql.org/docs/current/static/sql-savepoint.html

* Incremental and on-line backups:
...
Oracle8: Yes.
PostgreSQL: No.

Postgresql now supports a form of on-line backups by
archiving it's logs that contain only incremental changes
from the last full backup.
http://www.postgresql.org/docs/current/static/backup-online.html

* Access to multiple databases in one session:
....
Oracle8: Each session can use data from many instances, using
transparent distributed SQL access.
PostgreSQL: Only switching between databases. No support
for selecting data from different databases.

The option "dblink" module provides a mechanism for
making a query that spans databases in a single session.
An example is hidden in here.
http://www.postgresql.org/docs/current/static/queries-table-expressions.html
It's not as transparent as Oracle's, but it's quite
useful in some cases. Note that it can even link
to Microsoft SQL databases, and (i think) oracle.

* Subqueries in SQL query:
...
PostgreSQL:Sql compliance with Oracle.

Actually, I think PostgreSQL deviates from Oracle in places
where Oracle deviates from the SQL spec; so PostgreSQL
follows DB2 (and the SQL standard)'s way of handling
subqueries instead. An example, is that Oracle
doesn't like "AS ..." after a subquery.