What DB-Type do people use for Geo Information Systems as OODBs fade away

#11

Quote:

Hope this clears up some of the GIS and RDBMS relationships.
Thank You !!!!

Finally somebody with some on topic info :-)

Cheers, Wolfgang

#12

"Ed Yu" <ekyu (AT) sc (DOT) rr.com> wrote

Quote:

Most of the GIS systems out there use RDBMS. The major players are:

ESRI - Oracle, DB2, MSSQL, etc...
MapServer (open source) - PostgreSQL

There are a couple of indexing options available (e.g. grid indexing for
raster type objects, allowing one to spatially divide your features
(objects) into multiple grid levels).

The nature of GIS application are very different from data driven
applications and their tunning methdology centralized on how to
effectively
use RDBMS to minimize the number of features (objects) returning from the
underlying RDBMS when using maps as the primary user interface. You'll be
suprise that graph traversal is not such a common thing in GIS as compare
to
putting the icon on the map (which is the majority of what GIS application
does).

Hope this clears up some of the GIS and RDBMS relationships.

Yes... thank you.
--
Bob Nemec
Northwater Objects

#13

<...>

Quote:

In an OODB it would be object with object
references to its related nodes and the page storage pattern would
reflect
the usage pattern (or it could be explicitly set by the application ...
like with GemStone cluster buckets).

Yes, as I said, I would physically cluster the nodes according to the
usage pattern.

How do you 'cluster' nodes with an RDB?

Quote:

With an RDB I'm assuming a node would be
represented by rows in one or more tables.
Don't assume.

Fair enough. So how would you represent a 'node' in an RDB?

Quote:

So, if I have a cluster of 40 related nodes, how do I avoid the table
I/O for the join?

By physically clustering the related nodes according to the usage pattern.
Why do you demand I repeat myself?

I understand the theory (which is the point you keep repeating) but you have
not said 'how' you would implement node representation & clustering in an
RDB.

FWIW: I'd really like to keep this civil. I enjoy a good debate but not one
littered with personal insults. I 'demand' nothing of you; but if you (Bob
Badour) continue to fill your posts with snide remarks and put downs then
you'll be ignored.
--
Bob Nemec
Northwater Objects

#14

"Bob Nemec" <bobn (AT) rogers (DOT) com> wrote

Quote:

...
In an OODB it would be object with object
references to its related nodes and the page storage pattern would
reflect
the usage pattern (or it could be explicitly set by the application
....
like with GemStone cluster buckets).

Yes, as I said, I would physically cluster the nodes according to the
usage pattern.

How do you 'cluster' nodes with an RDB?

Physically. Oracle does it by defining a cluster key and by mapping that key
to attributes of tables to cluster.

Quote:

With an RDB I'm assuming a node would be
represented by rows in one or more tables.
Don't assume.

Fair enough. So how would you represent a 'node' in an RDB?

Physically? Any way I want.

Quote:

So, if I have a cluster of 40 related nodes, how do I avoid the table
I/O for the join?

By physically clustering the related nodes according to the usage
pattern.
Why do you demand I repeat myself?

I understand the theory

Physical clustering has nothing to do with relational theory; although, some
computing theory would apply.

Quote:

(which is the point you keep repeating) but you have
not said 'how' you would implement node representation & clustering in an
RDB.

Yes, I have. You either cannot comprehend the answer or you simply refuse
to.

Quote:

FWIW: I'd really like to keep this civil. I enjoy a good debate but not
one
littered with personal insults. I 'demand' nothing of you; but if you
(Bob
Badour) continue to fill your posts with snide remarks and put downs then
you'll be ignored.

So, ignore me. It's your loss.

#15

Wolfgang Keller wrote:

Quote:

Question: What do the Geo Information Systems guys use as their
databases?
* RDBs with performance problems
* RDBs which extensive tuning
* OODBs anyway - despite the fact that they are a bit off the mainstream
* a mixture of RDBs and BLOB data
* what else?

You seem to have already reached your conclusions.

An Object/Relational DBMS that supports objects as column values (domains) is a good
choice. People are using our ORDBMS for GIS applications.

--
Lee Fesperman, FirstSQL, Inc. (http://www.firstsql.com)
================================================== ============
* The Ultimate DBMS is here!
* FirstSQL/J Object/Relational DBMS (http://www.firstsql.com)

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

What DB-Type do people use for Geo Information Systems as OODBs fade away

comp.databases.object comp.databases.object

Re: What DB-Type do people use for Geo Information Systems as OODBs fade away - 09-12-2003 , 02:16 AM

Re: What DB-Type do people use for Geo Information Systems as OODBs fade away - 09-12-2003 , 06:55 AM

Re: What DB-Type do people use for Geo Information Systems as OODBs fade away - 09-12-2003 , 07:04 AM

Re: What DB-Type do people use for Geo Information Systems as OODBs fade away - 09-12-2003 , 07:36 AM

Re: What DB-Type do people use for Geo Information Systems as OODBs fade away - 09-23-2003 , 04:45 AM