Solaris lseek when reading shape files

[Frank Warmerdam]

> > Don Drake wrote:
> > > I'm using street-level data broken out by counties (tileindexed) and
> > > I'm running into some performance problems on Solaris.  We have this
> > > working on Linux, similar maps take 5 seconds max and on Solaris they
> > > take 45 seconds.
...
> > > The seeks continue on for about a million more lines (seriously) and
> > > this takes forever.
> > >
> > > This is a really inefficient way to scan a file, what can I do?
> > >
> > > I"m running Mapserver 4.2.5 on Solaris 9.

Don,

Looking at the pattern of seeks and reads, it would seem that stuff
is getting read in 8K chunks which I would presume is being done by
the C stdio library in response to lots of little reads in mapserver.
Similarly it would seem that the low level seeks are being generated
by the stdio library.

In other words, I don't think this is under the control of MapServer.
I'm not sure why things are so much slower on your Solaris box.
As SteveW mentions, you didn't have the qix before but you say
it didn't help.  The qix should ensure that only (roughly) the right
data is getting read.   Are you essentially rendering everything?
Have you verified that it is really the IO that is slowing you down?

Best regards,
--
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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and watch the world go round - Rush    | Geospatial Programmer for Rent