Adding funtions to postgresql (Not - )e: Please Help: PostgreSQL Query Optimizer

Ühel kenal päeval, P, 2005-12-11 kell 17:55, kirjutas Carlos Moreno:
> Hi,
>
> I'm very new to this list -- I've been using and advocating PostgreSQL for
> no less than 4 or 5 years now, and have participated in some of the other
> mailing lists, but never on this one.
>
> My question is (short version): how would one go about adding a new
> (built-in) function to PostgreSQL?

Ask your question as a separate post, not as an answer t another
thread :)

> I'm interested in adding additional hash functions -- PG supports, as part
> of the built-in SQL functions, MD5 hashing. So, for instance, I can simply
> type, at a psql console, the following:
>
> select md5('abc');
>
> My "feature request" (which again, I'd like to implement it myself) would
> be the ability to do:
>
> select sha1('xyz'), sha256('etc');
>
> (At least these two -- maybe for completeness it would be good to have
> sha224, 384, and 512, but I guess SHA1 and SHA-256 would be a very good
> and sound starting point)

Take a look at the pgcrypto contrib module (in src/contrib/pgcrypto )

Not only does it show how to add functions, but it also provides many of
the ones you need.

----------------
Hannu