I am working with Solaris on SPARC almost exclusively and I believe Josh said that Sun was the one who found the bursty behavior with scans. Has it been confirmed that this is the case on all/most platforms?
Myron Scott -----Original Message----- From: Tom Lane <[EMAIL PROTECTED]> Subj: Re: [HACKERS] Support Parallel Query Execution in Executor Date: Sun Apr 9, 2006 11:48 am Size: 1K To: Gregory Maxwell <[EMAIL PROTECTED]> cc: pgsql-hackers@postgresql.org "Gregory Maxwell" <[EMAIL PROTECTED]> writes: > On 4/9/06, Tom Lane <[EMAIL PROTECTED]> wrote: >> So before we go inventing complicated bits of code with lots of added >> overhead, we should first find out exactly why the system doesn't >> already work the way it's supposed to. > But is that really the behavior we should expect? Certainly. If the OS has readahead logic at all, it ought to think that a seqscan of a large table qualifies. Your arguments seem to question whether readahead is useful at all --- but they would apply *just as well* to an app doing its own readahead, which is what is really getting proposed in this thread. Before we go replacing a standard OS-level facility with our own version, we need to have a much clearer idea of why the OS isn't getting the job done for us. Otherwise we're likely to write a large amount of code and find out that it doesn't work very well either. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq