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Re: MySQL on T2000

Chris Lawrence <chris@nrsys.org> writes:
> I've done a good amount of fine tuning of the database, but I'm
> finding any query of complexity taking sometimes as much as 30x longer
> to execute than on same-era x86 hardware running Debian.

MySQL query execution is single threaded (one query in one thread).

The T2000 chips (and T1000 before it) have absolutely awful single
threaded performance - they're all about concurrency, not single thread

So these are really not the machines to run complex single queries
on. They're more suited to many small queries at once.

What doesn't help is that unaligned memory accesses abound in the MySQL
server (I once switched the GCC flags for generating code to handle
unaligned access... urgh)

30x sounds a little high... but I wouldn't be surprised if you had said
10 or 20x.

It'll also very much depend on MySQL version you're using. ASsuming
current debian, 5.5 should be the best possible...

Stewart Smith

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