Thread: Checksum/Hash Functions

Checksum/Hash Functions

From
"Bryan White"
Date:
Does PostgreSQL have any built-in check sum or hash functions.

I want to be able to compute a checksum of a string as I display a record to
the user and when the user updates the record compare the checksum in the
update statement.  I can do the checksum on the client side but it would
save the overhead of an additional select statement at update time if the
checksum could be computed on the database backend.

I know I could write my own function to do this but I first wanted to check
if there was a function already setup to do it.  I have looked at the
documentation but did not find anything.

---------
Bryan White
This email represents the consensus opinion
of the many voices in my head.



Re: Checksum/Hash Functions

From
"Joshua b. Jore"
Date:
Look in contrib/crypto (I think it was crypto). There are some hash
functions and other crpto stuffs in there.

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On Thu, 30 May 2002, Bryan White wrote:

> Does PostgreSQL have any built-in check sum or hash functions.
>
> I want to be able to compute a checksum of a string as I display a record to
> the user and when the user updates the record compare the checksum in the
> update statement.  I can do the checksum on the client side but it would
> save the overhead of an additional select statement at update time if the
> checksum could be computed on the database backend.
>
> I know I could write my own function to do this but I first wanted to check
> if there was a function already setup to do it.  I have looked at the
> documentation but did not find anything.
>
> ---------
> Bryan White
> This email represents the consensus opinion
> of the many voices in my head.
>
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org
>


Re: Checksum/Hash Functions

From
"Joel Burton"
Date:
There are some hashes in the contrib/pg_crypto addition. You may need to
install this specifically (it's a separate RPM, or, if you install from
source, it's in the contrib/ folder).

- J.

Joel BURTON | joel@joelburton.com | joelburton.com | aim: wjoelburton
Knowledge Management & Technology Consultant

> -----Original Message-----
> From: pgsql-general-owner@postgresql.org
> [mailto:pgsql-general-owner@postgresql.org]On Behalf Of Bryan White
> Sent: Thursday, May 30, 2002 9:53 AM
> To: pgsql-general
> Subject: [GENERAL] Checksum/Hash Functions
>
>
> Does PostgreSQL have any built-in check sum or hash functions.
>
> I want to be able to compute a checksum of a string as I display
> a record to
> the user and when the user updates the record compare the checksum in the
> update statement.  I can do the checksum on the client side but it would
> save the overhead of an additional select statement at update time if the
> checksum could be computed on the database backend.
>
> I know I could write my own function to do this but I first
> wanted to check
> if there was a function already setup to do it.  I have looked at the
> documentation but did not find anything.
>
> ---------
> Bryan White
> This email represents the consensus opinion
> of the many voices in my head.
>
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org
>