hash key lookup with an EXTRA key ...

prabu · Post by **prabu** » Wed Aug 31, 2005 10:39 am

Hi DS folks,

i have 2 hash files . one is called streamhash and the other is called referencehash. there are 2 keys in streamhash and 3 keys in referencehash .

i mapped stream K1 to reference K1 and stream K2 to reference K2. i need the K3 in referencehash for some other purpose. so to shut up DS i give a lookup like referencehash.K3 for the Key K3. it shows a red line but compiles alright, when i run , the lookup donest seem to go thr.

i would appreciate a quick response froms someone

example:-

without the extra key in referencehash, it works fine

streamhash K1 , K2
referencehash K1, K2

but when
streamhash K1 , K2
referencehash K1, K2 , K3 and K3.referencehash=K3.referencehash in tranformer , it doesnt work.

please throw some light

thank you

roy · Post by **roy** » Wed Aug 31, 2005 1:32 pm

Hi,
Do you have any other columns besides k3 in your first lookup?
If not perhaps a multi value ok k3 at firt a k1 & k2 key columns later normalizing it to generate the new 3 column as key in a new hash file.

IHTH,

ray.wurlod · Post by **ray.wurlod** » Wed Aug 31, 2005 4:26 pm

It won't work using a Hashed File stage. A Hashed File stage can only perform a lookup against the entire key.

You can set it up to use a UV stage to perform the lookup against a partial key. Search the forum for methods. Search on-line help for multi-row returns from reference inputs.

prabu · Post by **prabu** » Thu Sep 01, 2005 11:53 am

[quote="ray.wurlod"]It won't work using a Hashed File stage. A Hashed File stage can only perform a lookup against the entire key.
[/quote]

Hi ray,
thanks a lot for the help. trying to get more clarity , can't i peform something like 1=1 , reference3rdKey=reference3rdKey in the [b]keyExpression[/b] to notify the DS to perform the partial key match.

when i have tried 1=1, it takes the key value to be 1 and the
reference3rdKey=reference3rdKey is always null.

please let me know if this is possible(partial key lookup) using Hashfile stage :oops:

thanks

[/b]

prabu · Post by **prabu** » Thu Sep 01, 2005 11:54 am

ray.wurlod wrote:It won't work using a Hashed File stage. A Hashed File stage can only perform a lookup against the entire key.

Hi ray,
thanks a lot for the help. trying to get more clarity , can't i peform something like 1=1 , reference3rdKey=reference3rdKey in the keyExpression to notify the DS to perform the partial key match.

when i have tried 1=1, it takes the key value to be 1 and the
reference3rdKey=reference3rdKey is always null.

please let me know if this is possible(partial key lookup) using Hashfile stage

thanks

[/b]

ray.wurlod · Post by **ray.wurlod** » Thu Sep 01, 2005 5:11 pm

No.

Only entire key lookup is possible using a Hashed File stage.