Hi.
On Thu 2002-06-06 at 19:17:10 +0200, [EMAIL PROTECTED] wrote:
[...]
> But... is this the only feature of mysql which is dependant on the
> processor architecture?
See it the other way: You are not garantueed more than 31 tables in a
join. If you happen to have a 64Bit architecture, you can use more.
> I'm kind of nervous about this, because I'm currently working on a 'very
> normalized' database schema, and it is possible I will need more than 31
> tables in a single select... including multiple joins to the same tables, of
> course. It would be very bad if my design turned out to be 64-bit
> dependant...
AFAIK, if you need so many tables, you get a major problem: MySQL
figures out the best join order by trying all combinations. This
becomes increasingly slow as you are going to join more tables. In
other words: Trying to use 30 tables in one select probably will be
too slow as that it would matter whether so many tables are allowed in
a join or not.
Of course, you could work around it by using STRAIGHT_JOIN, but I
assume it is to cumbersome to figure out the optimal join order for
all SELECTs.
Bye,
Benjamin.
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