Re: Dynamic data model, locks and performance

On 29/07/10 11:15, Pierre Thibault wrote:

> What I would like to do is enable users to create their own data model.

Then, really, SQL databases aren't wonderful for your needs. You can use
them for dynamic, user-defined schema, but you'll always be swimming up
hill.

> 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.

Google "EAV"

This has known problems. It works, but it's kind of like bolting floats
onto a car and trying to use it as a boat. Not very nice.

Really, I'd be researching dynamic schema databases, object stores,
key/value set stores, etc. Such things are outside my personal
experience, though, and I can't really advise you much on technologies.
Beware of the latest No-SQL fad platforms, though; you might land up
being better off with something older and more stable even if it's less
fashionable than CouchDB or whatever is currently "in" today.

--
Craig Ringer

Tech-related writing: http://soapyfrogs.blogspot.com/