> >> >>key relationships?
> >> >
> >> > MyISAM can't FK's.
> >> Yes it can, they're just not enforced.
> > LOL - that's just like saying that MyISAM supports transactions
> > if you only do transactions that are a single statement...
> > In other words: useles.
> Somehow I use these "useles" foreign keys to create relational databases.
> A foreign key is merely a column which references a primary key or a
> key in the same or another table.
> I think you're confusing referential constraints with foreign keys.
In my book, referential constraints and foreign key constraints (the full
are the same.
> Even in
> database systems that support referential constraints and cascade
> dependencies, the usage of such constraints on foreign keys is optional
> dependant on your desire to trade-off referential integrity for
> In some systems, the performance penalty of enforcing referential
> constraints and doing deletions in dependant tables simply cannot be
> afforded during high usage hours for databases that serve real-time
> (I work in telecom for example), and therefore one may choose to implement
> cleanup process during very low usage hours in the middle of the night to
> find orphaned records, delete them, and then optimize the table. This
> allows you to avoid deleting anything but the primary record while people
> are waiting on the phone, which for MyISAM has the added benefit of
> concurrent insert/select to continue in the dependent tables.
I'm not going to do a serious answer on this one if this is really what
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