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KSDS V/S Internal Array


IBM Mainframe Forums -> JCL & VSAM
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Sowmya Ramachandra

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Joined: 11 May 2007
Posts: 20
Location: Canada

PostPosted: Wed Jul 30, 2008 1:26 am
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Hi ,

Could anyone let me know whether accessing a record stored in KSDS file by passing a Key is better or Storing a data in sequential file and loading it into an internal array in the program and then accesing it is better from the performance perspective.
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Terry Heinze

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Joined: 14 Jul 2008
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Location: Richfield, MN, USA

PostPosted: Wed Jul 30, 2008 2:30 am
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It depends on several factors: Number of records in the VSAM file, total number of VSAM reads vs. table searches will be done on the average, how often the VSAM file is updated, total amount of memory an internal table will use (usually not a problem these days). You need to provide more detail to get a good answer.
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Terry Heinze

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PostPosted: Wed Jul 30, 2008 2:32 am
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Since I cannot edit my posts, I wanted to add that memory searches will outperform I/O almost always, but there are other considerations, too.
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Sowmya Ramachandra

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PostPosted: Wed Jul 30, 2008 3:28 am
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The no. of the records in the file is supposed to me low volume say abt 50-100 records.
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Terry Heinze

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PostPosted: Wed Jul 30, 2008 3:37 am
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And what about the other factors I mentioned? They all play a part.
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dick scherrer

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Joined: 23 Nov 2006
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PostPosted: Wed Jul 30, 2008 6:39 am
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Hello,

How many records are in the "real" file (rather than this reference data?

Can the real file be put in sequence by the value that is used to search the array/vsam data?

As Terry mentioned, the other info requested could help us help you.
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