Pre-load file to memory-- HASHFILE STAGE

aaha_naga · Post by **aaha_naga** » Tue Feb 12, 2008 5:53 am

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?

asitagrawal · Post by **asitagrawal** » Tue Feb 12, 2008 6:18 am

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.

ray.wurlod · Post by **ray.wurlod** » Tue Feb 12, 2008 6:23 am

There is no such thing as a hash file stage, therefore your question is moot.

DS_FocusGroup · Post by **DS_FocusGroup** » Tue Feb 12, 2008 6:27 am

i think the poor guy meant "Hashed file " .....

hamzaqk · Post by **hamzaqk** » Tue Feb 12, 2008 6:32 am

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

MOHAMMAD.ISSAQ · Post by **MOHAMMAD.ISSAQ** » Tue Feb 12, 2008 7:06 am

Can anyone tell me what's the difference between hash "ed" file and "hash" file?

asitagrawal · Post by **asitagrawal** » Tue Feb 12, 2008 7:08 am

With Respect to DataStage, it is "HASHED FILE STAGE"...

ray.wurlod · Post by **ray.wurlod** » Tue Feb 12, 2008 3:28 pm

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.)

Pk39565 · Post by **Pk39565** » Sat Feb 23, 2008 12:39 am

Hashed file is one in which the links go out from file.
and Hash file is one in which links come in

ray.wurlod · Post by **ray.wurlod** » Sat Feb 23, 2008 4:04 am

That statement is complete rubbish. And 100% wrong.

It's always "hashed" file.

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Pre-load file to memory-- HASHFILE STAGE

Pre-load file to memory-- HASHFILE STAGE

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