Re: Apparent deadlock for simultaneous sequential scans

Dear Tom,
>
>
> pgsql-bugs@postgresql.org writes:
> > Apparent deadlock for simultaneous sequential scans
>
> > However, if more than one application is run at once, the performance
> > deteriotates drastically.
>
> So is it a deadlock, or a slowdown?  How many is "more than one"?

With two processors running the same query, it appears to be a
slowdown.  When I look at the system calls, the backends were
executing about one read per second. With six processors running the
same query, it appeared to be a deadlock -- no I/O's were being issued
over the time that I watched.

"More than one" means two or more.

Thanks. --Bob

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