Hi,
 
i am a new member of this list and interested in speeding up my sqlite 
queries.

I am using SQlite in a 3d environment which is close to Google Earth or 
Nasa WorldWind.

We have a city database that is being queried regurlarly depending on 
the lat/long position of the viewport in order to show city names and 
labels.

Plus, there are additional databases for special features, like natural 
hazards and catastrophies.

The city database has around 840.000 records,  the following schema and 
weights currently short under 40Mb:

sqlite> .schema cities
CREATE TABLE Cities (NAME_DDS TEXT, CLASS_DDS NUMERIC, POPEST_DDS 
NUMERIC, LONGI
TUDE_DDS NUMERIC, LATITUDE_DDS NUMERIC);
CREATE INDEX class ON Cities(CLASS_DDS ASC);
CREATE INDEX latlon on Cities(latitude_dds,longitude_dds);

My questions are:

- how do I speed up the queries? For small lat/long windows, and high 
classes for the cities, i get long query times (e.g. about 600ms)
Is this reasonable to ask for, or IS that already a top speed for this 
kind of query?

- I have indexed latitude AND longitude,as you can see above. Is this ok?

- I came across the EXLPAIN command, and have read an email by someone 
on this list on how to analyze my queries. I should probably do that, 
yet i am unfamiliar with reading the output of the Explain command.

Thanks for your time and eventual help,

-- 
Christophe Leske

www.multimedial.de - [EMAIL PROTECTED]
http://www.linkedin.com/in/multimedial
Lessingstr. 5 - 40227 Duesseldorf - Germany
0211 261 32 12 - 0177 249 70 31


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