IDS Forum

RE: Useostime Question on Solaris

Posted By: Bruce Simms
Date: Thursday, 6 March 2008, at 10:58 a.m.

In Response To: Re: Useostime Question on Solaris (Art S. Kagel (Oninit))

Art,

Thanks for all you do for Informix and I was looking as I knew you had
something but had not been able to find it.

Bruce Simms
Data Base Services
TALX Corporation
2330 Ball Drive
St. Louis, MO 63146

Phone (314) 214-7703
FAX (314) 983-3238
bsimms@talx.com

-----Original Message-----
From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of
Art S. Kagel (Oninit)
Sent: Thursday, March 06, 2008 9:35 AM
To: ids@iiug.org
Subject: Re: Useostime Question on Solaris [11517]

Bruce Simms wrote:
> Does any one have any test/experience on the cost difference on
setting
> USEOSTIME to 1?
>

The cost is VERY low, Bruce. It was made an ONCONFIG parameter because
way back when, SCO Xenix and some other UNIXes did not have an efficient

system call to provide high resolution time data so it was costly on
some platforms. Today all OSes that IDS runs on provide an efficient
implementation of gettimeofday() (or the Windoze equivalent) which is
the system call that IDS now uses on UNIX. It is VERY cheap.

I used it to calculate the maximum resolution of gettimeofday() and
therefore DATETIME YEAR TO FRACTION(5) on different platforms calling it

in a tight loop up to 100 million times todetermine if there was any
value to storing more than FRACTION(2) resolution. I'm going from
memory here (and I posted the resolution results on CDI a few years
ago), but on Solaris the resolution was ~1/300 seconds and the test
program reported that an average of 300-500 calls to gettimeofday)()
returned the same time value within the loop which also had to include
the two integer value comparisons and possibly an if test. That makes
the runtime cost of a call somewhere in the neighborhood of 1/150000
seconds on 1.2GHZ single core UltraSparc II (or III?) processors (24 IB)

the last time I ran the test. Darned efficient I'd say.

I can give you the source for the test program if you want it.

Art S. Kagel
Oninit

> Bruce Simms
> Data Base Services
> TALX Corporation
> 2330 Ball Drive
> St. Louis, MO 63146
>
> Phone (314) 214-7703
> FAX (314) 983-3238
> bsimms@talx.com
>
>

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Messages In This Thread

• Useostime Question on Solaris
  Bruce Simms -- Thursday, 6 March 2008, at 10:06 a.m.
  • Re: Useostime Question on Solaris
    Art S. Kagel (Oninit) -- Thursday, 6 March 2008, at 10:34 a.m.
    • RE: Useostime Question on Solaris
      Bruce Simms -- Thursday, 6 March 2008, at 10:58 a.m.
    • Re: Useostime Question on Solaris
      Jonathan Leffler -- Saturday, 8 March 2008, at 2:28 a.m.
  • Re: Useostime Question on Solaris
    Walter Lowich -- Friday, 7 March 2008, at 10:08 a.m.

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