[mapserver-users] MS-SQL / OGR Query Length Problem

[Frank Warmerdam]

Ben Madin wrote:
> Roughly, it would seem that between about 1600 and 1700 characters of 
> SQL kills the process. It can be very simple query (just straight data), 
> and shorter more complex queries work. cutting excess white space can 
> make a difference.
> 
> So, is it a limit of OGR or ODBC that I can't find any reference to. I 
> can't see that it is a problem with SQL Server, and I have had (I think) 
> longer SQL queries working using postgis...
> 
> My question is, does anyone know where this might be breaking / 
> happening? (bonus points if you know whether it is a configuration 
> setting that we could tune!)

Ben,

I have reviewed the OGR ODBC driver and I see no obvious point at which
a long query should be a problem.  I have also skimmed the MapServer core
and php_mapscript code and I see no obvious problem.

I assume you are placing the SQL query in the DATA statement in the
map file?

I would suggest a few steps to try and isolate this:

  o See if you can reproduce it against other ODBC datasources.
  o See if you can reproduce it with mapserv instead of php_mapscript
  o See if you can reproduce it with just OGR and no MapServer.

If you can reproduce the problem in a form that I can run at my end without
undue complexity, I'd be willing to dig in somewhat deeper.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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