A spatial data infrastructure (SDI) is a data infrastructure implementing a framework of geographic data, metadata, users and tools that are interactively connected in order to use spatial data in an efficient and flexible way.

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6
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2answers
335 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 ...
3
votes
1answer
356 views

How does R-Tree outperform B-Tree for simple check if a point is within a rectangle

For things like find nearest neighbors, I can undertand that R=Tree can outperform B-Tree. R-Tree can kick out more obviously false points. However, for simple check of a point in a rectangle, it's ...
0
votes
1answer
183 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 ...
1
vote
0answers
107 views

Why do we need myisam spatial extension anyway?

If just to determine whether a point is within a rectangle, What is wrong with this query? EXPLAIN SELECT DISTINCT TB.ID, TB.Latitude, TB.Longitude FROM TableBusiness AS TB WHERE ...
1
vote
1answer
183 views

What is the SQL command to get 20 closest points from some center location

There are 1.6 million rows. Must not compute distance for all rows. Spatial index is available This is the table structure. The name of the table is businessauxiliary. So yes I used MyIsam, added ...
0
votes
2answers
1k views

How do I get spatial index feature if I mainly use innodb?

My current strategy is to create another table in myisam that contains those spacial information. Then if I want to find 20 closest business, I'll just use join. Is this a good idea?
10
votes
3answers
921 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 ...
2
votes
1answer
549 views

How to store GPS coordinate and search places in a radius from a NoSQL DBMS (like DynamoDB)

My team need a DBMS like DynamoDB to store large amount of data, principally places and coordinates. I've considered to use some GIS-based DBMS (like PostGIS) with an index on the POINT, but DynamoDB ...
1
vote
0answers
117 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 ...
1
vote
1answer
2k views

Repair with keycache in mysql runs EVERY time. Can't even log why it's happening

I have a MyISAM table w/ ~1million rows and two indexes - one's a three-column key, and the other is a spatial index for bounded SELECT statements on a separate point column. My insert statements ...
3
votes
3answers
697 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
55 views

sdo_tune.quality_degradation returning negative values

While running the sdo_tune.quality_degradation function on one of our Oracle databases most of the results were around 1 but a number had values like -556127.225. Does this mean that these indexes ...
4
votes
1answer
163 views

Spatial data modelling tools

Is there anything like MySQL workbench for PostGIS? Something that supports SQL output and geometry types would be nice. CLARIFICATION: I am trying to implement the Land Administration Domain ...
1
vote
0answers
208 views

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

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
4k 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 ...
2
votes
2answers
292 views

How do I set a geography point to be the North Pole?

I tried to execute this query on my SQL Server 2008 R2 instance: UPDATE ITEMS SET GEOG=geography::STPointFromText('POINT(0 90)', 4326); SQL Server returned the following error: ...
2
votes
1answer
268 views

Creation of spatial index locks the table for hours

I used this code to create a spatial index in SQL Server 2008 R2: BEGIN TRANSACTION SET QUOTED_IDENTIFIER ON SET ARITHABORT ON SET NUMERIC_ROUNDABORT OFF SET CONCAT_NULL_YIELDS_NULL ON SET ANSI_NULLS ...
3
votes
1answer
153 views

SQL Server - Using spatial data

I'm using SQL Server 2008 R2 for real-time location aware service. The service mostly receives location data (lat/lon) from a user and returns locations around the user. The data is being sent from ...
6
votes
1answer
342 views

Permission to create Spatial Index

Permissions required to create a Spatial Index on a table, for this BOL says: Requires ALTER permission on the table or view. User must be a member of the sysadmin fixed server role or the ...
8
votes
2answers
1k 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, ...