[OSGeo-Standards] Simple Text Format For Transfer of Simple Spatial Features (Killing the GML 3 Beast)

Jody Garnett jgarnett at refractions.net
Wed Aug 29 18:02:39 EDT 2007

Do look at the SimpleFeature profile and what ESRI did to make GML3 
"useful". Out of your list [3] is in contradiction with [1]... unless 
you want to use a hack I though of. Make a generic spatial index that 
tracks file offsets, use this to "filter" an input stream of your simple 
format (text?) (jumping around the file as needed) presenting the result 
as a flat stream that can be parsed in a simple manner. It will be 
murder to keep that index udpated.

You also left out one; do you need to edit the file? If so fixed length 
records is a good thing ...  and so on. You can see why most projects 
are taking an embeded database (making a file format is so 70s).

> We really don't want to pass around databases for various reasons. One
> of my own personal reasons is the added complexity of JDBC. We also want
> to support data transfer between programs written in languages other
> than Java.
> We know we want a file format that meets the following requirements:
> [1] Simple, Simple, Simple
> [2] Human readable, not binary.
> [3] Ability to be indexed for faster access to features.
> [4] No need for an external schema.
> [5] Easy to write and read (parse).
> If there is an existing format that meets these requirements please let
> me know. Jody is correct when he says we want to avoid duplicating a
> file format that already does this.
> I have my suspicions about the existence of such a format. I would think
> someone in the OpenJUMP community would have pointed it out by now, but
> I could be wrong.
> Maybe the C/C++ folks have an idea.
> Landon (A.K.A. - The Sunburned Surveyor)
> -----Original Message-----
> From: Jody Garnett [mailto:jgarnett at refractions.net] 
> Sent: Wednesday, August 29, 2007 2:50 PM
> To: Landon Blake
> Cc: standards at lists.osgeo.org
> Subject: Re: [OSGeo-Standards] Simple Text Format For Transfer of Simple
> Spatial Features (Killing the GML 3 Beast)
> Yet another format is never a great idea :-) If you really want another 
> format why not punt H2 databases around? It is what the SQLLite file 
> format crazy in the C++ world is all about ... think even FDO does 
> something like that?
>> [1] A CSV file in which the first row contains feature attribute 
>> names, the second row identifies feature attribute data types using 
>> standard XML data types and WKT for geometry attributes, and in which 
>> the other rows contain the actual attribute values, one feature per
> row.
> You are welcome to look at the property file format we use as an example
> in GeoTools.
>> [2] A restricted form of GML 2 that will eliminate the need for an 
>> external schema and simplify parsing. Think of this as "GML 2 
>> Resurrected".
> This is the way to go;
> - you will find that the OGC has a SimpleFeature profile of GML3 that 
> can be put to good use.
> - ESRI also has something insane to the same effect
> Not sure you will every eliminate the need for an external schema - but 
> why not put it inline at the top of the document? Consider it a "header"
> for the rest of the file ... that is how WSDL and MS does it.
> Cheers,
> Jody
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