Обсуждение: Fw: Oracle2PostgreSQL Migration with PL/pgSQL

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Fw: Oracle2PostgreSQL Migration with PL/pgSQL

От
"Christopher Kings-Lynne"
Дата:
Saw this in the Oracle newsgroup...

Chris

----- Original Message -----
From: "DA Morgan" <damorgan@exesolutions.com>
Newsgroups:
comp.databases.oracle.server,comp.databases.oracle.misc,comp.databases.oracl
e.tools,comp.databases,comp.infosystems.www.databases
Sent: Sunday, March 09, 2003 6:40 AM
Subject: Re: Oracle2PostgreSQL Migration with PL/pgSQL


> Guido Stepken wrote:
>
> > Hi, out there !
> >
> > I am writing on a Oracle to PostgreSQL migration handbook.
> >
> > Seems, that PostgreSQL 7.4 (still beta) works quite fine in emulating
> > pl/SQL language. Clustering, MVCC (Multi Versioning Concurrency
> > Control), hot backup ... large databases (> 1 Tera), Query
> > caching/hashing, server side scripting with pl/pgSQL emulation seems to
> > work now. Very powerful RAD tools exist for postgresql. Oracle tools can
> > be used for development, due to compatibility.
> >
> > PostgreSQL IMHO more and more becomes a Oracle killer. Worth, writing a
> > small book about it ;-)
> >
> > I am still seeking small documentation / experiences, perhaps pl/SQL ->
> > pl/pgSQL code for comparisons, benchmarks (yes, i know, difficult to
> > interpret), experiences with toolkits (RAD, UML ...)....code should be
> > unter a free license for being published, if possible.......
> >
> > any hints welcome
> >
> > tnx in advance, Guido Stepken (mailto:stepken @ little - idiot.de)
>
> I love this from the PostgreSQL web site:
>
> "Multi-version concurrency control(MVCC)
>
> This removes our old table-level locking, and replaces it with a locking
> system that is superior to most commercial database systems. In a
> traditional system, each row that is modified is locked until committed,
> preventing reads by other users. MVCC uses the natural multi-version
nature
> of PostgreSQL to allow readers to continue reading consistent data during
> writer activity. Writers continue to use the compact pg_log transaction
> system. This is all performed without having to allocate a lock for every

> row like traditional database systems. So, basically, we no longer are
> restricted by simple table-level locking; we have something better than
> row-level locking."
>
> Apparently copying the design of the Oracle counts as doing something not
> done by "traditional" database systems. Nothing like marketing folks to
lack
> in integrity. If Oracle isn't a "traditional" database system ... I'd like
> to know what is.
>
> The day PostgreSQL and Oracle killer? I'd check the label on the
> medication.  ;-)
>
> Not that it is a bad product. But anytime they get in Larry or Bill's way
> ... they'll do to them what was done to Fox and Informix.
>
> Daniel Morgan
>