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Pre-load file to memory-- HASHFILE STAGE

Posted: Tue Feb 12, 2008 5:53 am
by aaha_naga
Hi,

In Hashfile stage it shows preload file to memory- Enabled and disable etc.

Which thing is used to increase the performance in hash file stage?

Re: Pre-load file to memory-- HASHFILE STAGE

Posted: Tue Feb 12, 2008 6:18 am
by asitagrawal
aaha_naga wrote:Which thing is used to increase the performance in hash file stage?
"Enable write to cache" , "Preload file to memory" can be configured to enhance the performance of hashed file stage

Best would be to go through the Server Job Developer's Guide.

Posted: Tue Feb 12, 2008 6:23 am
by ray.wurlod
There is no such thing as a hash file stage, therefore your question is moot.

Posted: Tue Feb 12, 2008 6:27 am
by DS_FocusGroup
i think the poor guy meant "Hashed file " ..... :lol:

Posted: Tue Feb 12, 2008 6:32 am
by hamzaqk
the performance of a Hash "ed" file and not a hash file depends on a few more factors than just this one. the Hash "ed" and not the hash file creates two files with the extension of .data and .overflow which need to be monitored. if the size of the .overflow file is greater than the .data file for a particular Hash "ed" file and not hashfile, you might want to read about modulus etc and set the thier number according to that for the Hash "ed" file and not the hash file your creating.

I hope it helps :P

Posted: Tue Feb 12, 2008 7:06 am
by MOHAMMAD.ISSAQ
Can anyone tell me what's the difference between hash "ed" file and "hash" file?

Posted: Tue Feb 12, 2008 7:08 am
by asitagrawal
With Respect to DataStage, it is "HASHED FILE STAGE"... :!:

Posted: Tue Feb 12, 2008 3:28 pm
by ray.wurlod
The data storage structure is called a hashed file because key values are "hashed" (passed through a hashing algorithm) to determine their physical location.

A hash file is a tool for shaping a block of hash. There is no such thing as a hash file in DataStage.

(There is also a "hash table". This is an IT term and refers to a table with a finite number of rows (or, sometimes, "slots") in memory. These can be used as part of a sorting algorithm or to index data.)

Posted: Sat Feb 23, 2008 12:39 am
by Pk39565
Hashed file is one in which the links go out from file.
and Hash file is one in which links come in

Posted: Sat Feb 23, 2008 4:04 am
by ray.wurlod
That statement is complete rubbish. And 100% wrong.

It's always "hashed" file.