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From:Roger Baklund Date:June 7 2002 5:10pm
Subject:Re: Maximum JOINED tables
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* Victoria Reznichenko
> RB> mysql is considered to be platform independant, and I suppose
> RB> MySQL AB is trying to keep it that way...?
>
> Roger, MySQL is platform independent.

I did not say it was not... :)

> It works on any platform with
> the same data, but if the architecture is 64 bit, you can use it for more
> power than on 32 bit.

If the feature set is different on different platforms, the product is not
truly platform independant. The number of joins in a query is a part of the
feature set, IMHO.

It is fully possible that right now someone is developing an application on
a 64bit platform, not knowing that the system will not work on 32bit
platforms simply because they have too many joins.

It is not the 'lack of power' on 32bit platforms that will prevent it from
working, it's the _platform dependant_ limitation in the number of joins.

Ok, _now_ I am saying that mysql is not platform independant, but of course,
this 'incompatibility' is not something most users will run into, so I guess
we could say it is 99% true that mysql is platform independant, or that
mysql is 99% platform independant... :)

(There are also issues with letter casing in table names and different
implementations of the floating point methods.)

> You can change it (set 63) in 32 bit CPU by hack in compilation, but
> making join map 64 bit on 32 bit box makes the work of MySQL slower.

And in this case 'slower' means...? (If we are talking about milliseconds
per query, I don't see the problem. If we are talking about milliseconds per
traversed row, there would be a problem.)

Has anyone ever done this hack, and if so, was the result usefull?

Thank you for the info, Victoria! :)

...and sorry to those who got fooled by me pointing at crashme telling them
the limit was 64 in 3.23.x...

--
Roger
sql

Thread
Maximum JOINED tablesArthur Fuller5 Jun
  • Re: Maximum JOINED tablesRoger Baklund5 Jun
RE: Maximum JOINED tablesWalt Weaver5 Jun
  • RE: Maximum JOINED tablesAndrew Hazen5 Jun
RE: Maximum JOINED tablesWalt Weaver5 Jun
RE: Maximum JOINED tablesWalt Weaver5 Jun
  • Re: Maximum JOINED tablesSabine Richter5 Jun
    • Re: Maximum JOINED tablesDan Nelson5 Jun
  • Re: Maximum JOINED tablesRoger Baklund5 Jun
    • Re: Maximum JOINED tablesHarald Fuchs6 Jun
      • RE: Maximum JOINED tablesRoger Baklund6 Jun
        • Re: RE: Maximum JOINED tablesVictoria Reznichenko6 Jun
          • Re: Maximum JOINED tablesRoger Baklund6 Jun
            • Re: Maximum JOINED tablesBenjamin Pflugmann7 Jun
              • Re: Maximum JOINED tablesRoger Baklund7 Jun
                • Re: Re: Maximum JOINED tablesVictoria Reznichenko7 Jun
                  • Re: Maximum JOINED tablesRoger Baklund7 Jun
                • Re: Maximum JOINED tablesBenjamin Pflugmann7 Jun
                  • Re: Maximum JOINED tablesRoger Baklund8 Jun
                    • Not using indexes???Jon Frisby8 Jun
                      • Re: Not using indexes???Erv Young8 Jun
                      • Re: Not using indexes???bvyas38 Jun
                        • RE: Not using indexes???Jon Frisby8 Jun
                          • Re: Not using indexes???Benjamin Pflugmann8 Jun
                            • Re: Not using indexes???Erv Young10 Jun
                            • RE: Not using indexes???Jon Frisby10 Jun
                              • php+mysql+multiple lines qrycristian ditoiu10 Jun
                                • Re: php+mysql+multiple lines qryBrent Baisley10 Jun
                                  • Re: php+mysql+multiple lines qrycristian ditoiu10 Jun