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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2
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1answer
190 views

Scaling of PostGIS vs MySQL cos/sin calculations [closed]

I need to sort database rows according to GPS coordinates (or any other geographical representation). The way I've understood it, MySQL Spatial Indexes are too buggy at the time of writing (at least ...
1
vote
1answer
987 views

GeomFromText in trigger has error

I have this trigger: DELIMITER $$ CREATE TRIGGER geometrytrigger BEFORE INSERT ON users FOR EACH ROW BEGIN SET NEW.user_geometry=GeomFromText(NEW.user_geometry); END$$ DELIMITER ; when I insert a ...
3
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1answer
236 views

Geographic Hierarchies in a OLAP Cube / Data Warehouse

Are the following geographic hierarchies correct? Do any US/Canadian area codes cross state/province lines? Do any US/Canadian counties cross state/province lines? Are there countries with counties ...
3
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1answer
593 views

Insert performance with Geography column

I've been tasked with inserting data into a SQL Server table with a geography column. I've found that my times for doing inserts (same data 1.5 million rows) go up increasingly. I started out with no ...
2
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1answer
1k views

What is the syntax for querying a spatial column?

What is the right syntax to get all the points within the bounding box? The table consists of a lat and lng column and a spatial column "pt" generated from the lat/lng values. calculated the topleft ...
2
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1answer
684 views

Visualiser for spatial query results

This question Whats the easiest way to get sql 08 spatial data onto a map? (and many other articles) recommends Craig Dunn's Geoquery, but all the download links appear to be kaput. SQL Server ...
6
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2answers
9k views

What's the difference between POINT(X,Y) and GeomFromText(“POINT(X Y)”)?

I'd like to store some geometric positions in my MySQL database. For this I use the POINT datatype. Almost everywhere I read that the function GeomFromText should be used to insert data in the table. ...
1
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0answers
67 views

Combine Oracle locator instance with Oracle spatial instance with db link

we plan to have two oracle databases, one with oracle spatial installed, the other one just has the locator option. Is it possible to create an oracle database link between the two databases in order ...
4
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1answer
345 views

T-SQL and GPS co-ordinates

I'm looking to store GPS co-ordinates in an MS SQL Server DB for location matching of users with GPS-enabled mobile phones. I've read about STDistance on MSDN, but it only appears to exist in SQL ...
0
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2answers
780 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 ...
3
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1answer
1k views

MongoDB geospatial query with sort - performance issues

I have query (which is very slow ~2,5s): db.markers.find({ latlng: { '$within': { '$box': [ [ -16, -140 ], [ 75, 140 ] ] } } }).sort({_id: -1}).limit(1000) When I run explain for this query I get ...
1
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1answer
2k views

Convert spatial points data to line data for use in Line Layer in SQL Server Reporting Services (SSRS)

I have a query that returns the fields Order, Lat, Long, SpatialData, <OtherStuff>. SpatialData is a point. I want to create a line layer that draws lines between my points based on the order ...
1
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1answer
1k views

$nearSphere returns too many data. What am I missing? Am I wrong? Is it a bug? Does other see the same thing?

I noticed that $near and $nearSphere returns completely different data and I got suspicious. After all, when latitude is near equator it sphere distance shouldn't differ a lot from euclidean distance. ...
2
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2answers
810 views

Error updating sql server geography type in trigger

I have the following trigger in my database: CREATE TRIGGER dbo.triggerGeocodedAddressUpdate ON dbo.Party AFTER UPDATE AS IF UPDATE(Latitude) UPDATE pt SET pt.GeocodedAddress = ...
5
votes
1answer
6k views

Mongodb - Returning the points nearest to a location, with distance

What is the MongoDB's equivalent to this query: SELECT 111151.29341326 * SQRT( pow(-6.186753-`Latitude`, 2) + pow(106.772835-`Longitude`, 2) ...
3
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3answers
678 views

Which graph database for search engine and gis?

I just learned there are "graph databases" out there, which are more suited for two applications "search engine" and especially "gis". To avoid discussions weather a relational DB is better suited ...
1
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2answers
313 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 ...
2
votes
1answer
323 views

Problem with shortest distance calculation in PostGIS

While working with PostGIS pgrouting, for calculating the distance between two roads (lines) I'm using the shortest_path function. The logic is based on start_point(Start_id) and end_point(end_id) ...
1
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2answers
134 views

Trying to create PostGIS database

I am trying to create a spatially enabled PostGIS database by following the PostGIS documentation. In the short version, i executed, createdb yourdatabase createlang plpgsql yourdatabase But I did ...
0
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0answers
22 views

A spatial query return no result when obviously there is result [duplicate]

Possible Duplicate: Less restrictive query return less result due to simple removing one additional constraint SELECT DISTINCT TB.ID, TB.Latitude, TB.Longitude, ...
6
votes
2answers
431 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
418 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
195 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
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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
201 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 ...
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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?
12
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3answers
1k 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
720 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
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0answers
124 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
3k 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
820 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, ...
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0answers
60 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
194 views

Spatial data modelling tools [closed]

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
241 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 ...
10
votes
2answers
5k 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
356 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
279 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
165 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
430 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
2k 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, ...