From: | "D(dot) Duccini" <duccini(at)backpack(dot)com> |
---|---|
To: | andre <andre(at)liquidprivacy(dot)net> |
Cc: | pgsql-sql(at)postgresql(dot)org, pgsql-novice(at)postgresql(dot)org |
Subject: | Re: Guarantee uniqueness of PGP key |
Date: | 2002-05-21 02:37:33 |
Message-ID: | Pine.GSO.4.03.10205202136460.18715-100000@ra.bpsi.net |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-novice pgsql-sql |
good grief
yeah, look at using the MD5 or SHA1 hash of the key itself
-d
On Mon, 20 May 2002, andre wrote:
> Hi,
>
> More generically, how do I best guarantee that any large varchar is unique
> before inserting?
>
> In my application, I need to ensure that each e-mail address and
> corresponding PGP public key are both unique.
>
> I originally implemented this by adding a uniqueness contrainst to both
> columns. easy.
>
> The problem is that some PGP keys are over 2713 bytes, and postgres (7.2)
> gives the error:
>
> ERROR: btree: index item size 4336 exceeds maximum 2713
>
> I thought perhaps I could use a hash or rtree index, but neither of them work
> for unique-ness.
>
> I saw in another posting that it may be possible to raise this limit to 8k or
> so, but I don't want to do this because 1) it requires a recompile of
> postgres (and rollout to dev, stage, prod machines), and 2) a key could
> theoretically be longer than 8k anyway.
>
> I can guarantee unique-ness by removing the index and doing a select before
> the insert. If there is a matching row, then I am trying to insert a dup.
> bail.
>
> My concern is that doing this without an index will be monumentally slow for
> any large-ish number of keys.
>
> Any bright ideas? All suggestions appreciated.
>
> /andre
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 6: Have you searched our list archives?
>
> http://archives.postgresql.org
>
-----------------------------------------------------------------------------
david(at)backpack(dot)com BackPack Software, Inc. www.backpack.com
+1 651.645.7550 voice "Life is an Adventure.
+1 651.645.9798 fax Don't forget your BackPack!"
-----------------------------------------------------------------------------
From | Date | Subject | |
---|---|---|---|
Next Message | Bruno Wolff III | 2002-05-21 11:54:42 | Re: Guarantee uniqueness of PGP key |
Previous Message | Joel Burton | 2002-05-21 00:21:53 | Re: [SQL] Guarantee uniqueness of PGP key |
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 2002-05-21 02:47:40 | Re: [SQL] Bug with Daylight Savings Time & Interval |
Previous Message | Command Prompt, Inc. | 2002-05-21 02:25:11 | MacOS X Shared Buffers (SHMMAX)? |