Hi, working on DS 7.x . whats the need to use Hash files for joins when we can do the same with tables ? and if it is about hashing which makes it faster. in Teradata you can hash the key columns .... so when to choose what ? and why prefer hashfiles over indxed tables to carry out a join of the sequential file on the base table .
Thanks !
Hash file or indexed tables ?
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Hi
The advantage of using hashed file is that it will be stored in the server where the DS server is running . The turnaround time to read and write will be faster than reading/writing the data to database.
Added to this there are some more advantages using Hashed File.
Any one correct me if i am wrong .
Thanks
Ravi
The advantage of using hashed file is that it will be stored in the server where the DS server is running . The turnaround time to read and write will be faster than reading/writing the data to database.
Added to this there are some more advantages using Hashed File.
Any one correct me if i am wrong .
Thanks
Ravi
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It's possibly even better than being local; DataStage hashed files can be cached in memory, so that the fast key-based access (via the hashing algorithm) is at least three orders of magnitude faster than disk-based access.
In DataStage the term is "hashed" file, not "hash" file.
In DataStage the term is "hashed" file, not "hash" file.
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Any contribution to this forum is my own opinion and does not necessarily reflect any position that IBM may hold.
Any contribution to this forum is my own opinion and does not necessarily reflect any position that IBM may hold.