Re: Ad-hoc table type? - Mailing list pgsql-hackers

From tomas@tuxteam.de
Subject Re: Ad-hoc table type?
Date
Msg-id 20080929064631.GA19449@tomas
Whole thread Raw
In response to Re: Ad-hoc table type?  ("David E. Wheeler" <david@kineticode.com>)
Responses Re: Ad-hoc table type?  ("David E. Wheeler" <david@kineticode.com>)
List pgsql-hackers
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On Sun, Sep 28, 2008 at 09:24:48PM -0700, David E. Wheeler wrote:
> On Sep 28, 2008, at 17:46, Tom Lane wrote:
>
>> BTW, I think it is (or should be) possible to create an index on
>> hstore->'mycol', so at least one of the reasons why you should *need*
>> to switch to a "real" database column seems bogus.

[...]

> I'm not sure what that means. Can you create normal btree or hash indexes 
> on hstore columns? And is the index useful for both `@>` and `?`?

That means that those operations are supported by a GiST (or GIN) index,
that is:
 "find the records where col contains 'foo => 1, bar => 2'"

is supported by the index. Likewise for "is contained in" and "has key".
It's a bit like having mini-indexes on all keys (although I guess not
that efficient). Pretty cool, I'd say.

Regards
- -- tomás
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