On 07/29/2010 05:15 AM, Pierre Thibault wrote:
2010/7/28 Craig Ringer <cr...@postnewspapers.com.au
<mailto:cr...@postnewspapers.com.au>>
On 29/07/10 07:06, Pierre Thibault wrote:
I doubt anyone can make any useful recommendations without a more
complete explanation of what you're trying to achieve and why you want
to do what you have described.
Thank you Craig,
Yes, I was not very specific. I have an idea in mind. Everyone knows
about Craig's List and the hype about NoSql databases. This seems to
be cool to do full text searches in a lot of data. But what about
doing more formal searches based specific criteria like dates, numbers
or other kind values on specific fields? This where an SQL database
shines.
What I would like to do is enable users to create their own data
model. Enable them to create a model and make it evolve. For example,
it would be cool to create a model to represent car adds. Then, the
buyers can search adds using the previous model with specific criteria
like the color of the car they want.
I thought about using a table where each row would represents a field
in the dynamic model. The row would contain a fields for each possible
data type supported but only one of them would be used. This would
waste a lot space and it would also be hard to query efficiently but I
will not have to change the schema as users create new models.
Otherwise, I would create a standard data model and apply the changes
as users update their models.
I also like to support inheritance so we can have a simple model for
regular adds and more specfic models with more fields for car adds for
example.
I have a really hard finding how to implement my idea efficiently. So
the advice of experienced database developers is what I am looking for.
Re Pg-specific stuff, you should look into hstore. It might offer
a way
to avoid the need for dynamic table re-structuring.
I thought about using maps for the entities of my domain model. hstore
seems to be an interesting avenue.
You might want to take a look at TopicMaps, http://www.topicmaps.org/
One of the greatest topicmap-engines is opensource: http://www.ontopia.net/
It uses, if you want, an RDBMS (PostgreSQL is fully supported) underneath.
--
Andreas Joseph Krogh<andr...@officenet.no>
Senior Software Developer / CTO
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