[mapserver-users] testing mapserver large files rendering improvements

Stephen Woodbridge woodbri at swoodbridge.com
Thu May 15 12:21:44 EDT 2008

Daniel Morissette wrote:
> Paul Ramsey wrote:
>> I've been thinking about auto-building qix files... it would fix this
>> problem and also fix the problem of the shape file that gets updated
>> and out-of-synch with its index file.
>> I think programmers will hate the idea, but users, maybe they will
>> like it? What do you think?
> You guessed right... I, as a programmer, am not keen on that kind of 
> magic behavior. I like to think of dataset access by MapServer as a 
> read-only operation, for security and various reasons I would not want 
> to allow write access to the data dirs. But I'd be happy to see a 
> "Mapfile optimizer" tool that does this kind of stuff.
> BTW, a step we could easily take in the short term is add a msDebug() 
> message at level >= MS_DEBUGLEVEL_TUNING warning users that a given 
> shapefile hass no .qix and adding one could increase performance.
> There could also be a test added at the same debug level and if the .shp 
> file date is newer than the .qix then produce a warning saying that the 
> .qix may be out of date.
> Daniel

-1 on magic happens.
    1) performance issues if the files already exist
    2) what if the filesystem is readonly
    3) what if the filesystem overflows
    4) etc

+1 on optimizer tool(s)
    1) find <dir> -name \*.shp -exec shptree {} \;

But please keep up with your wonderful stream of ideas and improvements.

-Steve W

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