Re: Drawbacks of using BYTEA for PK?

John Sidney-Woollett <johnsw@wardbrook.com>

From: "John Sidney-Woollett" <johnsw@wardbrook.com>
To: "Chris Travers" <chris@travelamericas.com>
Cc: pgsql-general@postgresql.org
Date: 2004-01-13T08:50:05Z
Lists: pgsql-general
Careful...

If two (or more) clients (in the same network) are going through a
firewall that performs NAT, then they could appear to have the same IP
address if the NAT address pool is small (single address).

Appending a sequence would help resolve that issue though.

John Sidney-Woollett

Chris Travers said:
>
> ----- Original Message -----
> From: "Alex Satrapa" <alex@lintelsys.com.au>
>> As long as you don't use RFC1918 addresses, the IPv4 address(es) of the
>> host should be unique for the Internet. Append/prepend a 32 bit
>> timestamp and you have a 64bit unique identifier that is "universally"
>> unique (to one second).
>
> Aarrgh...  So if you have 2 inserts in the same second, you have key
> collision?  Why not append a sequence to that so you have:  Unique address
> || timestamp || sequence value.  In a case such as this I can see why you
> might want to use md5() to hash that value.
>
> Best Wishes,
> Chris Travers
>
>
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