It'd be interesting to do a FILE.UGAGE ON, run the program, look at the stats,
then do FILE.USAGE OFF. Another thing to look at is LIST.READU EVERY while the
program is running. If there appears to be an issue there, increase the lock
table sizing parameters in uvconfig. Troy is correct in asking about the select
method; no sense in processing the same data multiple times, so that's the
first thing to eliminate. The second is file sizing. If you have to follow
dozens of links to read & write for each record, that consumes a ton of
resources. You'll see that in the FILE.USAGE report, or you could just look at
ANALYZE.FILE to see if the file is poorly sized.
> From: [email protected]
> To: [email protected]
> Date: Mon, 30 Apr 2012 20:47:59 -0400
> Subject: Re: [U2] READU vs READ
>
> Depends on how much <twisted logic> you have... Seriously, I would guess
> that your bottleneck is disk access.
>
> Are you using basic SELECT and READNEXT ? Is your list in sorted order
> (SSELECT) or not (SELECT).
>
> Processing the updates in group order will minimize the I/O. I don't think
> the READU overhead on today's machines are anything that would slow it down.
> I just tested 100,000 records with and without locking and I get six seconds
> both ways. Because it was cached data, my test eliminates disk i/o and
> measures the lock overhead which seems to be negligible on universe 11.1.1.
>
>
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Dave Laansma
> Sent: Monday, April 30, 2012 5:33 PM
> To: [email protected]
> Subject: [U2] READU vs READ
>
> If I don't HAVE TO lock a record before modifying it writing it back, will a
> program run significantly faster if I just WRITE it back without locking it
> first? I'm updating about 700,000 records and it's just taking TOO long.
>
>
>
> I DO understand the risks of other users changing the record's content during
> so let's not go down that road. I'm interested in the SPEED dialog.
>
>
>
> Thank you folks!
>
>
>
> Sincerely,
>
> David Laansma
>
> IT Manager
>
> Hubbard Supply Co.
>
> Direct: 810-342-7143
>
> Office: 810-234-8681
>
> Fax: 810-234-6142
>
> www.hubbardsupply.com <http://www.hubbardsupply.com>
>
> "Delivering Products, Services and Innovative Solutions"
>
>
>
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