This document discusses how location-based services and GIS data can add a new dimension to business data by incorporating location. It provides an overview of key GIS concepts like objects, surfaces, and coordinate systems. It also explains how to represent GIS data in databases using datatypes, functions, and spatial indexing. Finally, it gives examples of practical uses of GIS data for mapping, analytics, and querying locations.

1. Building Location Based Services
What about adding a new dimension to your data?
Anders Karlsson
Principal Sales Engineer, MariaDB

2. Location based services and GIS
Do you know all there is to know about your business from
your data?
What if you could add another dimension to that data?
What if that dimension could be used to bring a new way to
use and view your data?
And what if that dimension could come more or less free?

3. Agenda
● GIS concepts explained
● GIS data in Databases
○ Datatypes
○ Functions
○ Indexing
● Practical examples of using Location Data in Databases

4. An introduction to GIS

5. GIS Systems and GIS Data
● GIS systems are systems that specialized in GIS applications
○ The leader in this field is ESRI
○ Research
○ Mapping
○ Exploration
● Today, with GPS receivers in almost every car and cellphone this is changing
○ Navigation
○ Mapping objects on maps
○ GIS data is become an important components of social networks

6. GIS objects
● A GIS object is something that is mapped in coordinates on some kind of map
or grid
○ A point
○ A line
○ A polygon
■ There are numerous specialized polygons of course. Square, rectangle etc.
○ Other geometric shapes

7. GIS Surfaces
● The surface the GIS objects are mapped on
can be anything
○ A simple 2d map
○ The earth
● The above are the most common uses
○ Of course a map is a subset of the earth, but many maps reflects such a small part of the earth
so it can be simplified as being flat
○ Note: If your earth is flat, many assumptions made on this and the following slides are largely
incorrect

8. Latitude and Longitude
Latitude
0
Longitude
0
40.715088, -74.015289

9. GIS Terms

10. GIS Terms – WKB and WKT
● WKT and WKB are standard GIS formats for representing GIS shapes (up to 4
dimensions)
● WKT – Well Known Text
● WKB – Well Known Binary
● Both are standardized by the Open GIS Consortium (OGC) and is used by
most database systems to represent GIS data

11. GIS Terms - MBR
● MBR (Minimum Bounding Rectangle) - A rectangular shape that is
the smallest one to encompass some other shape
● In the illustration to the right
○ Point A is within the Polygon
and within the MBR of the
Polygon
○ Point B is within the MBR
of the Polygon but not within
the Polygon itself
MBR
POLYGON
A
B

12. GIS Terms - SRID
● SRID (Spatial Reference Identifier) is what defines the Grid where we
place our shapes
○ In other words, the SRID defines how we map our flat map onto a
curved reality, such as the
earth
○ There are several different LAT/LONG
mappings
● There is also a “flat” or Euclidian SRID
○ This is what is used by MariaDB

13. GIS in databases

14. GIS Database types
● The supported shapes are arranged in a hierarchy
○ Top level is GEOMETRY
● There is also support for collections of shapes
○ MULTIPOLYGON for example

15. GIS Database types
● GIS datatypes are organized in a hierarchy (see below)
● To store any kind of GIS data, the type to use is GEOMETRY
● To create an index of a GIS datatype column, you create a SPATIAL INDEX
○ Note that you can also use BTREE indexes on GIS data, but these are usually only good for
exact matches and are far from as powerful as a SPATIAL index
GEOMETRY
POINTPOLYGONLINESTRING COLLECTION
MULTILINESTRING MULTIPOLYGON MULTIPOINT

16. GIS data indexing
● Rtree (Rectange Tree) - A way to index GIS shapes by creating a
tree-like hierarchy using the MBR of the shape
● Without Rtree indexes, we would be limited to exact location
searches for GIS data in databases
● Using Rtree indexes we can index
operations such as
○ Find all shapes that are
contained within another shape
○ Find all shapes that overlaps a given shape
○ Find all lines that crosses a given polygon
R2
R1
R6
R3
R4
R7
R5
R1 R2
R3 R4 R5 R6
R7

17. Creating a data tables containing GIS data
CREATE TABLE state(state VARCHAR(2) NOT NULL PRIMARY KEY,
name VARCHAR(25) NOT NULL,
state_fips VARCHAR(2) NOT NULL,
shape GEOMETRY NOT NULL,
UNIQUE(state_fips),
SPATIAL INDEX(shape));
CREATE TABLE road(id INTEGER NOT NULL PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(120) NOT NULL,
state VARCHAR(2) NOT NULL,
shape GEOMETRY NOT NULL,
length DOUBLE,
SPATIAL INDEX(shape),
FOREIGN KEY(state) REFERENCES state(state));

18. GIS Functions
● There are three groups of GIS functions
○ Constructors, for example
■ POINT to create a POINT
■ POINTFROMTEXT to create a POINT from a textstring
○ Geometry relations, for example
■ CONTAINS to determine of one geometry contain another
■ OVERLAPS to determine of one geometry overlaps another
○ Geometry attributes, for example
■ GEOMETRYN – Get a specific geometry from a GEOMETRYCOLLECTION
■ AREA – Get the area of a POLYGON
■ CENTROID – Get the mathematical center of a POLYGON or MULTIPOLYGON

19. GIS Data – Getting practical

20. GIS Data goes to work
● Mapping
○ Showing locations on maps
○ Showing venues given some condition and a current location
● Locating
○ Locating people
○ Finding the location of a car accident
○ Finding houses for sale in the current area
● Big data analytics, Visualization
○ Find trends in geographies
○ Where do my customers come from
○ Where do my customers NOT come from
● The use cases are many more than used to be the case
○ Cellphones have GPS receivers
○ GPS Location can be retrieved by a an application

21. Populating GIS Data
● There is a wealth of free GIS data available
○ Government
○ Research
○ Other sources
● The most data you find is find is, regrettably, in shape or .shp files
● The good thing is that the shape format is, for the most part, open and documented
○ ESRI, the leader in Geospatial applications, created and develops the shp format
○ For Linux, you will find GDAL (Geospatial Data Abstraction Library) real helpful
○ GDAL is available in Linux repositories and contains libraries and tools
○ Among them is ogr2ogr, a Geospatial data format converter
○ Note that you need all the files in a set, not just the shp file!
$ ogr2ogr -f MySQL MySQL: "db,host=h1,user=anka,port=3306" -nln
roads -a_srs "EPSG:4326" roads.shp -lco ENGINE=InnoDB

22. Querying GIS data
MariaDB> SELECT r.name, s.state_name
FROM roads r JOIN states s ON CROSSES(r.shape, s.shape)
WHERE r.name LIKE 'US Route 101%'
GROUP BY r.name, s.state_name
ORDER BY MIN(Y(CENTROID(ENVELOPE(r.shape))));
+-----------------------------+------------+
| name | state_name |
+-----------------------------+------------+
| US Route 101, State Route 1 | California |
| US Route 101 | California |
| US Route 101 | Oregon |
| US Route 101 | Washington |
+-----------------------------+------------+
Get all states that US 101 passes through, ordered from south to north

23. Querying GIS data
MariaDB> SELECT s.state_name, SUM(r.length) length
FROM roads r JOIN states s ON CROSSES(r.shape, s.shape)
WHERE r.name LIKE 'US Route 101%'
GROUP BY s.state_name
ORDER BY MIN(Y(CENTROID(ENVELOPE(r.shape))));
+------------+--------+
| state_name | length |
+------------+--------+
| California | 1.770 |
| Oregon | 2.276 |
| Washington | 3.196 |
+------------+--------+
Get the length of US 101 in all the states that is passes through, ordered from south to north

24. Querying GIS data
MariaDB> SELECT state_name
FROM states
WHERE contains(shape, PointFromText('POINT(-73.985170
40.758902)'));
+------------+
| state_name |
+------------+
| New York |
+------------+
In which state is Times Square?

25. Conclusion
● GIS data adds a new dimension to your data
● Combining GIS data with your business data provides valuable insights
● Using GIS data provides a base for new ways of visualize data
● There is a lot of free GIS data out there, for you to use
● GIS data fits nicely into a relational structure and is fully supported by
MariaDB
○ Functions
○ Data types
○ Indexing
○ GeoJSON

26. Resources and further reading
● MariaDB GIS Features reference
○ Knowledge base: https://mariadb.com/kb/en/mariadb/gis-functionality/
○ Future plans: https://mariadb.com/kb/en/mariadb/mariadb-plans-gis/
● Open GIS Consortium (OGC) – Simple Features Access SQL
○ Reference: http://www.opengeospatial.org/standards/sfs
● R-Tree indexes
○ Wikipedia: https://en.wikipedia.org/wiki/R-tree
○ MariaDB Knowledge Base: https://mariadb.com/kb/en/mariadb/spatial-index/
● MariaDB GIS Datatypes
○ MariaDB Knowledge Base: https://mariadb.com/kb/en/mariadb/geometry-types/
● Google maps API
○ Google: https://developers.google.com/maps/

27. Thank you!
Building Location Based Services
Anders Karlsson
Principal Sales Engineer, MariaDB
anders @mariadb.com