5
votes
2answers
197 views

Less restrictive query return less result due to simple removing one additional constraint

Look at this query SELECT DISTINCT TB.ID, TB.Latitude, TB.Longitude, 111151.29341326*SQRT(pow(-6.185-TB.Latitude,2)+pow(106.773-TB.Longitude,2)*0.98839228980165) AS Distance FROM ...
0
votes
1answer
132 views

What database do most mobile start ups use? [closed]

mongodb? MySQL? PostgreSQL? If someone would add pluses and minus, let me know. Why I ask: I am a mobile startup. I need a database that supports spatial indexes. The spatial index must be able to ...
0
votes
0answers
140 views

Nearest neighbor search for 1.6 million points in myisam mysql

Say I want to find 20 closest business near me. Latter I want to see the next 20 closest, etc. Yes I have myisam. I have spatial indexes on the point. I am looking for actual command. Note: I am ...
6
votes
2answers
790 views

How do Application Like Yelp Retrieve distance information from data base efficiently

For example, say I have a table: Business(BusinessID, Lattitude, Longitude) All are indexed of course. Also there are 1 million records Say I want to find businesses closest to 106,5, for example, ...