2010/7/28 Craig Ringer
<craig@xxxxxxxxxxxxxxxxxxxxx>
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.
