Re: [NOVICE] Guarantee uniqueness of PGP key

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
>
>
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