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Re: (Re: Database is needed) PostGres95 is stronger then ...?
RHS Linux User wrote:
>
> On Thu, 3 Jul 1997, Shlomi Fish wrote:
>
> ...
> > consider PostGres95, which has a stronger SQL syntax and more features than
> > MySQL or miniSQL, but is probably considerably slower.
> >
> > Shlomi Fish
> >
>
> PostGres95 has a stronger SQL then ... ?
> I don't know about the other DBMS that you mentioned, but as much that I
> recall, PostGres95 basic SQL is quite limited. Perhaps if you do quite
> extensive programming yourself then what you wrote holds.
> Can you wrote some references and/or be more specific about where it is more
> strong ?
I worked for some time with Illustra, which is the commercial successor
to Postgres '95. (Michael Stonebraker of UC Berkeley developed Ingres,
its successor Postgres, then Postgres '95, and finally left academia to
go commercial with Illustra.) Ignoring the object-oriented extensions,
which were only fully developed in Illustra, AFAIK, there is something
you should understand about the SQL of these servers:
There is an early SQL standard, SQL 1, (I _think_ it's ANSI '89) which
is based on the original IBM SQL, that is (basically) supported by
Postgres. mSQL stands for mini-SQL, and contains only a subset of
that. In particular, it lacks joins, without which you can't do much in
a single query. Postgres builds off of the original SQL with many
non-standard extensions for constraints and so on, that are not part of
SQL per se, but are very useful AND powerful. Unfortunately, the
database engine itself does not do much in the way of performance
optimization, and unless you know what you are doing, it is NOT simple
to add these improvements in reliably. (It IS a BIG plus that you get
the source, though.)
The "SQL" that commercial databases like Informix and Oracle mean when
they talk about SQL is the later ANSI SQL, (SQL '92 ?) sometimes
referred to as SQL 2. From _that_ base each manufacturer adds their own
extensions. This is the "SQL" that you'll also find in most SQL books.
As I believe I've mentioned before, an EXCELLENT online resource for
selecting a database is Philip Greenspun's web site, where he has
published part of his book, "How to be a Web Whore Just Like Me," at
http://www-swiss.ai.mit.edu/wtr/dead-trees/index.html - in particular,
chapter 11, "Choosing a Relational Database" at
http://www-swiss.ai.mit.edu/wtr/dead-trees/53011.htm is a good read.
Good luck.
--
Eliyahu Skoczylas <eliyahu@pobox.com>
References: