Re: Asssociative Arrays: Best practices / snippets?

2009/5/23 Stefan Keller <sfkeller(at)gmail(dot)com>

> I have a use case where the I want to put an unforeseable number of
> key/value pairs in a column.
> Now, PostgreSQL has arrays as first class types.
> Are there any best practices and snippets (preferrably in plpgsql) for
> handling key/value pairs?
> -- S.
>

common relational practice is to use entity-attribute-value model to attach
any number of key/value pairs to any object, for example:
object( object_id, ... )
attribute ( attr_id, attr_name )
object_attribute ( object_id, attr_id, attr_value )

if your a lazy DBA and text key/values are all you need, did you look at
hstore? it might be enough.

my personal hstore experience is:
1) keep your key/values reasonably small; if you need structured data - do
not put it into hstore.
2) keep in mind that hstore indexing is limited, many search operations
require full table scan

--
Filip Rembiałkowski
JID,mailto:filip(dot)rembialkowski(at)gmail(dot)com
http://filip.rembialkowski.net/