Od: "Bob Hall" <[EMAIL PROTECTED]>
Temat: Re: [PHP-DB] Re: PostgreSQL versus MySQL
> > > The implication is that MySQL is not an RDBMS. The only attempt I
> > > know of to define an RDBMS was Codd's, and no DBMS has ever met the
> > > criteria he published in a paper in the late 80s (1986?). Even though
> > > Oracle doesn't meet the criteria of the best known definition (only
> > > definition?) of an RDBMS, we all seem to agree that Oracle is an
> > > RDBMS. An RDBMS is a DBMS designed to manage a relational database,
> > > and a database is relational because it stores data in linked,
> > > normalized tables.
> >
> >The only thing I question in this is that without transaction support,
> >what exactly is MySQL "managing"?
>
> The data in the normalized tables.
Of 12 Codd's rules (1985), MySQL doesn't meet four:
5 - full internal language implementation with transactional processing
support;
6 - using views for data modification;
10 - autonomous referential integrity mechanism built into database;
11 - autonomous data distribution.
Of SQL-92 instructions MySQL doesn't implement following:
CREATE | DROP SCHEMA, DECLARE LOCAL TEMPORARY TABLE, CREATE | ALTER | DROP
DOMAIN, CREATE | DROP CHARACTER SET, CREATE | DROP COLLATION, CREATE | DROP
TRANSLATION, CREATE | DROP VIEW, ALLOCATE | DECLARE | OPEN | CLOSE CURSOR,
COMMIT, ROLLBACK, FETCH, CLOSE, CREATE | DROP ASSERTION, SET CONSTRAINTS
MODE, SET SESSION AUTHORIZATION, SET TRANSACTION MODE, SET NAMES, SET
SCHEMA, SET TIME ZONE, ALLOCATE | SET | GET | DEALLOCATE DESCRIPTOR,
DESCRIBE, PREPARE, DEALLOCATE PREPARE, EXECUTE, EXECUTE IMMEDIATE, GET
DIAGNOSTICS
This set is about 85% of SQL-92 standart, but i didn't see any DBMS that
implements that all.
Of SQL-92 keywords, about 65% is absent in MySQL, but they are not too often
used even if they are present with significant exception of trigger and
procedural language.
Cheers
Jarek Zgoda
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