Re: Postgres performance comments from a MySQL user

On Thursday 12 June 2003 15:50, Ron Johnson wrote:
> On Thu, 2003-06-12 at 08:05, Martin Marques wrote:
> > On Mié 11 Jun 2003 12:29, Jonathan Bartlett wrote:
> > > 3) If your point was to move to a relational database, then you should
> > > choose Postgres. MySQL, although it's SQL, hardly qualifies as
> > > relational
> >
> > MySQL doesn't have relations at all, unless you put the InnoDB module,
> > which stamps down performance.
> >
> > An example I tried to do on a MySQL without InnoDB was:
> >
> > CREATE TABLE testing (
> > id INT,
> > word VARCHAR(20) REFERENCES other_table("word")
> > );
> >
> > (knowing that other_table exists (I prefiously created it) and has word
> > as a VARCHAR(20) field).
> >
> > An error is what I got.
>
> A table *is* a relation. You seem to be referring to foreign keys.
> Maybe MySQL has a different syntax?

It accepts syntax like this:

CREATE TABLE exmpl6 (
id INT,
blah TEXT,
INDEX(id),
CONSTRAINT id_fkey FOREIGN KEY (id) REFERENCES exmpl5(id) ON DELETE
NO ACTION
);

but ignores it silently if you omit the "type=innodb" after the table
definition (at least in 3.23.x versions).

(When developing for MySQL I have a list of gotchas which I
attach to the monitor, saves me many happy afternoons of
headscratching ;-)

Ian Barwick
barwick(at)gmx(dot)net