Re: Hashes from composite keys?
Date: Mon, 26 Jul 2010 17:04:02 -0700
Message-ID: <Knp3o.49212$Ls1.48395_at_newsfe11.iad>
On 7/26/2010 4:03 PM, Bob Badour wrote:
> Daniel Pitts wrote:
>
>> On 7/23/2010 1:14 PM, Karsten Wutzke wrote:
>>
>>> Hello,
>>>
>>> what are the best practices for generating hash codes from composite
>>> keys? I need to mimic something like what a composite index does. In
>>> fact, it's for mapping between relational keys and object IDs.
>>>
>>> Can anyone point me into the right direction please?
>>
>> Yes, don't use Hashing, but use a composite key. Aggregate the keys
>> into one value (eg, the BIT pattern of that one key value is the
>> concatination of the bit patterns of all the other values.)
>
> That's rather dumb advice.
Really? The OP said "I need to mimic something like what a composite
index does" Well, I suggested a simplified (yet correct) version of
what a composite index does.
-- Daniel Pitts' Tech Blog: <http://virtualinfinity.net/wordpress/>Received on Tue Jul 27 2010 - 02:04:02 CEST