Re: Returning bigint from C extension

From: Martijn van Oosterhout <kleptog(at)svana(dot)org>
To: Jason Armstrong <ja(at)riverdrums(dot)com>
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: Returning bigint from C extension
Date: 2009-11-23 08:37:24
Message-ID: 20091123083723.GA29028@svana.org
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On Mon, Nov 23, 2009 at 09:58:21AM +0200, Jason Armstrong wrote:
> How can I return a bigint value from a C extension function?
>
> I have a table with a bytea column:
>
> CREATE TABLE mydata(data bytea);
>
> I would like to select and index based on a subset of the data:
>
> CREATE FUNCTION get_key(bytea) returns BIGINT AS '/lib/data.so'
> LANGUAGE C IMMUTABLE;
> CREATE INDEX mydata_key_idx on mydata(get_key(data));

For a bigint you need to use the right return type: PG_RETURN_INT64()

> (And, as a side note, is the above code the correct way to use bytea
> data from C?)

Looks ok.

Have a nice day,
--
Martijn van Oosterhout <kleptog(at)svana(dot)org> http://svana.org/kleptog/
> Please line up in a tree and maintain the heap invariant while
> boarding. Thank you for flying nlogn airlines.

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