ravivundavalli (10) [Avatar] Offline
#1
1. The data you have very recently given for Paris Points, Lines,Polygons may pl be integrated with
ch03_data.sql

2. As the ReadMe.txt of raw_data_files, where Paris Points, Lines,Polygons are given
says
"You don't need these files to complete the core of chapter 3 exercises. These are provided for reference or if you would like to go thru the whole preparation yourself"
So put them together as suggested.
Unless one is expected to be perseverent.

3. VACUUM ANALYZE ch03.paris_hetero;
this cannot work nested with other lines, my PostGIS admonishes.

4. Typo in SQL, where UNION is given as UNON
regina.leo (265) [Avatar] Offline
#2
Re: Postgis in Action Ebook Chapter-3
Ravi,

The typo we have fixed in our current version of the chapter which hasn't been published on MEAP yet.

We apologize for this chapter being really confusing. I was really tempted to just leave out the whole osm loading code listings since I find them kind of distracting to the lessons we were trying to convey in this chapter. Unfortuantely its too late for us to take those code snippets out.

-- The problem with this chapter is that there are 2 ways to approach it --

1) Run thru every code listing as you are doing smilie, for the more patient intense user.
For those people that choose to do that, they don't need ch03_data.sql file at all since the first set of code listings build the core tables included in ch03_data.sql.

or (which we assumed most users would fall into)

2) Just read the first couple of listings to get a backgrounder of how paris_hetero was built and move on with the core lessons of the chapter which are
a) using inherited tables
b) using triggers
c) using rules

Unfortunately trying to explain it sounds more confusing than not explaining it at all.

We'll update the readme to reflect that you can skip
1) Skip running the code that builds paris_hetero and just use ch03_data.sql

OR

2)
skip loading ch03_data.sql and load the osm* files and build ch03 from the ground up using the code in code03.sql
regina.leo (265) [Avatar] Offline
#3
Re: Postgis in Action Ebook Chapter-3
Ravi,

We've updated the ReadMe.txts included in

http://www.postgis.us/downloads/ch03_code_data.zip


Let us know if that is any clearer. Unfortunately we can't change chapter 3 too much at this point aside from errata corrections since its gone off to proof readers.
ravivundavalli (10) [Avatar] Offline
#4
Re: Postgis in Action Ebook Chapter-3
Glad that you have not succumbed to the temptation of skipping OSM.
It is this kind of interaction with other domains like OSM that interests the Open Source fans. How you have used OSM data which is in general line and points to extract polygons
is fun.
Ravi