Tagged Questions

0
votes
2answers
209 views

migrate SQL Server geography data to PostGIS geometry data

I'm trying to use SSIS to transfer point data from a Geography column in SQL Server 2008 R2 to a geometry column in a Greenplum (Postgres 8.2.15) database with PostGIS. I know there's a way to do the ...
1
vote
2answers
168 views

PostgreSQL : Is this because of locks(row level)?

I have a table with approximately 2.1 million tuples. Which has latitude and longitude columns. I am trying to convert this into a geographic type (point with SRID). The function(procedure) I have ...
1
vote
1answer
158 views

postgis problem with shortest distance calculation

while working with POSTGIS pgrouting, for calculateing the distance between two roads(lines) i got the shortest_path function. But the logic is based on Start_point(Start_id) and end_point(end_id) ...
0
votes
2answers
76 views

Trying to create PostGIS database

I am trying to create a spatially enabled PostGIS database. I am following the PostGIS documentation, http://postgis.refractions.net/documentation/manual-1.5/ch02.html#id2648455. In the short ...
0
votes
1answer
131 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 ...
7
votes
3answers
457 views

Can spatial index help a “range - order by - limit” query

Asking this question, specifically for Postgres, as it has good supoort for R-tree/spatial indexes. We have the following table with a tree structure (Nested Set model) of words and their ...
1
vote
0answers
106 views

PostGIS - Effects of polygons with large number of verticies [closed]

I have a large table that stores, among other attributes, a geometry type. I have a GIST index on this attribute. However, when I perform even the most basic queries [say, select count(*) from table ...
3
votes
2answers
397 views

How do I design a database for continents, countries, regions, cities and POIs?

I am not a database designer so I'm having trouble designing database with GIS information. The goal is to create a system with continents, countries, regions (including states, sub-regions, ...
1
vote
0answers
132 views

PostGIS: Remove stale/obsolete geometry columns from the geometry_columns table

I understand that the function Populate_Geometry_Columns() inserts records in the geometry_columns table for geometry columns that are not yet listed there. However, an invocation of ...
8
votes
2answers
3k views

PostgreSQL vs. MySQL - Advantages / Disadvantages with a spatial component

We are the in the process of building out a web application that has a spatial data component. In the beginning our spatial data comparisons will take a given point and return matched overlapping ...