[Mapserver-users] OGR Join index

[Richard Greenwood]

Frank Warmerdam wrote:

> Richard Greenwood wrote:
> 
>> Totally cool! The indexes reduced execution time from over 2 minutes 
>> to about 2 seconds. (Joining 12000 spatial rows to 300 attribute 
>> rows). The index only seemed to be required on the attribute table.
>>
>> But of course, there's always one more question: I can not get ogrinfo 
>> to create an index on just a dbf file. It seems to require the 
>> associated shp and shx files also, even tho there is no spatial data 
>> there. Ogrinfo recognizes the dbf, but fails to create an index. e.g.
>>
>> $ ogrinfo listing.DBF
>>   INFO: Open of `listing.DBF'
>>   using driver `ESRI Shapefile' successful.
>>   1: listing (None)
>>
>> $ ogrinfo -ro . -sql "create index on listing using Pidn"
>>   INFO: Open of `.'
>>   using driver `ESRI Shapefile' successful.
>>   ERROR 1: CREATE INDEX ON failed, no such layer as `listing'.
>>
>> I don't see what functional purpose the shp and shx files server in a 
>> table having no spatial data. Any insight here?
> 
> 
> Rich,
> 
> This is working fine for me on a standalone .dbf file.  What is your
> ogrinfo source?  Are you on windows or linux?  I did it directly on a dbf
> file with no .shp and .shx with no problem.  I was on linux using a
> build-from-cvs but this area hasn't changed for a couple months as far as I
> know.
> 
> Best regards,

Ahhhh. Apparently my problem was that I DID have an associated MapInfo 
.tab and .ind. Sorry that I didn't mention this before. I suspect 
ogrinfo was reluctant to overwrite the existing .ind file.

Once again - Thank you. I have been cc'ing the mapserver-users list 
because join functionality has been discussed frequently in the past and 
the OGR Join fills a very nice nitch between the RDBMS methods and the 
more limited LAYER JOIN object.

Regards,
-- 
Richard Greenwood
www.greenwoodmap.com