added chapter 3

Author: Nick Gauthier

chapter-2/01-fks.md

@@ -62,7 +62,7 @@
 
 !SLIDE
 # Foreigner Gem
-### [http://github.com/matthuhiggins/foreigner](http://github.com/matthuhiggins/foreigner])
+### [http://github.com/matthuhiggins/foreigner](http://github.com/matthuhiggins/foreigner)
     @@@ ruby
 
     gem 'matthuhiggins-foreigner', 

chapter-3/01-geo.md

@@ -0,0 +1,110 @@
+!SLIDE
+# Chapter 3
+## Geospatial
+
+!SLIDE center
+# Not your typical index
+![K-D Tree](kdtree.png)
+#### [http://en.wikipedia.org/wiki/K-d\_tree](http://en.wikipedia.org/wiki/K-d_tree)
+
+!SLIDE center
+# PostGIS
+## Geospatial indexing and querying for PostgreSQL
+
+!SLIDE
+# Easy Ubuntu Install
+### Add PPA ppa:ubuntugis/ubuntugis-unstable
+### Install postgresql-8.4-postgis
+
+!SLIDE
+# Setup the language
+    @@@ sql
+    createdb my_db
+    createlang plpgsql my_db
+    psql -d my_db -f /usr/share/postgresql/8.4/
+      contrib/postgis-1.5/postgis.sql
+    psql -d my_db -f /usr/share/postgresql/8.4/
+      contrib/postgis-1.5/spatial_ref_sys.sql
+    psql -d my_db -f /usr/share/postgresql/8.4/
+      contrib/postgis_comments.sql
+
+!SLIDE
+# Setup your database
+    @@@ sql
+    CREATE sequence points_id_seq;
+    CREATE TABLE points (
+      id integer PRIMARY KEY
+      DEFAULT NEXTVAL('points_id_seq')
+    );
+    SELECT AddGeometryColumn(
+      'points', 'location', 4326, 'POINT', 2
+    );
+    CREATE INDEX points_location_idx 
+      ON points USING GIST ( location );
+ 
+!SLIDE
+# Create a point
+    @@@ sql
+    INSERT INTO points(location) VALUES (
+      ST_GeomFromText(
+        'POINT(-76.615657 39.327052)'
+      )
+    );
+ 
+!SLIDE
+# Find points in a radius
+    @@@ sql
+    SELECT * FROM points
+    WHERE ST_Distance(
+      location,
+      ST_GeomFromText('POINT(-76 39)')
+    ) < 1;
+
+!SLIDE
+# In Rails
+## GeoRuby
+### [http://georuby.rubyforge.org/](http://georuby.rubyforge.org/)
+## Spatial Adapter
+### [http://github.com/fragility/spatial\_adapter](http://github.com/fragility/spatial_adapter)
+
+!SLIDE
+# Will it blend?
+
+!SLIDE
+# 8,000,000 points
+
+!SLIDE
+# 5 years of data
+
+!SLIDE
+# Single EC2 Large @ 400rpm
+
+!SLIDE
+# Query: "What happened on my block last week?"
+
+!SLIDE
+# Avg 23ms response time
+## Database: 2.0ms
+## ActiveRecord: 6.8ms
+## Controller action + JSON: 14ms
+
+!SLIDE center
+# Remember compound indices from chapter 1?
+## Compound index on space and time
+![Spacetime](spacetime.png)
+#### [http://en.wikipedia.org/wiki/Spacetime](http://en.wikipedia.org/wiki/Spacetime)
+
+!SLIDE
+# There's more
+### Lines and polygons
+### Intersection operations
+### Partial and full containment
+### Distance calculation
+### Area computation
+
+!SLIDE
+# Can't touch this
+### MongoDB: flat earth model, only distance calculation
+### MySQL: containment via rectangles, no compound indexing
+### SQL Server: pretty good ... just icky
+### Sphinx + Solr: additional layer and pretty immature

chapter-3/kdtree.png

@@ -4,6 +4,7 @@
     {"section":"intro"},
     {"section":"chapter-1"},
     {"section":"chapter-2"},
+    {"section":"chapter-3"},
     {"section":"conclusion"}
   ]
 }