Re: My honours project - databases using dynamically attached entity-properties

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On Thu, Mar 15, 2007 at 12:49:10PM -0400, Andrew Dunstan wrote:
> Gregory Stark wrote:
> >"Ron Mayer" <rm_pg(at)cheapcomplexdevices(dot)com> writes:
> >
> >
> >>I have a system with many essentially user-defined fields, and was
> >>thinking of creating something similar to an Array type and writing
> >>some GIST indexes for it.

[...]

> >I think that's what hstore does. Honestly I'm not entirely certain though.

> Does hstore nest? My impression is that it doesn't. Which might well not
> matter, of course.

If what you mean is to have "mappings of mappings" then no.

Hstore implements a data type for a (finite) mapping (a set of key -> value
pairs, think "hash" for perl folks), with operations like "H1 contains
H2" (in the sense that all key-value pairs in H2 are also in H1)
supported by an index. Keys and values are strings.

But I don't see why it couldn't be extended to more structured data
types (one of the good things of hstore at the moment is its surprising
simplicity, because it provides a good example of what GiST is good for,
therefore I'd understand if the authors don't wanted to add that much
hair without need).

In my view it's one of the cutest applications of GiST.

Regards
- -- tomás
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