On Mon, 20 Sep 2004, Burke, S (Stephen) wrote:
> LHC Computer Grid - Rollout
> > [mailto:[log in to unmask]] On Behalf Of Steve Fisher said:
> > I am told that it is being caused by the new accounting code trying to
> > process 5 weeks of data - so MySQL is runnign *very* slowly.
>
> Can you give some guidance on what level of load R-GMA can cope with?
>
> Stephen
MySQL is trying to join 3 huge tables. It may be worth finding a smarter
way of doing this.
It is hard to define what load R-GMA can cope with, however I guess that
if we avoid very large tables then very long joins can be avoided. In the
LCG R-GMA implementation the result from the database is returned in one
big lump which can also be a problem if you simply do a "select * from
fred" and fred has lots of tuples. This problem will be avoided in the
gLite release. However what we really need is way to predict how long an
query will take.
Steve
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