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What are the advantages and disadvantages of VSAM

 
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mframes

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Joined: 29 Apr 2004
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PostPosted: Thu Apr 29, 2004 1:38 pm    Post subject: What are the advantages and disadvantages of VSAM
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what are the advantages and disadvantages of VSAM ?
which other dataset organisation has all the features to override its disadvantages ?
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superk

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PostPosted: Thu Apr 29, 2004 3:25 pm    Post subject:
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As compared to what? icon_question.gif
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mframes

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PostPosted: Thu Apr 29, 2004 5:06 pm    Post subject:
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superk,
i wanted to know abt the
1.advantages of VSAM over other data management systems ?
2.also advantages of VSAM applications over IMS ,DB2 applications?
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superk

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PostPosted: Fri Apr 30, 2004 12:33 am    Post subject:
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Since VSAM is only a storage access method, I can't see how you can make a comparison between it and a data management system such as DB2. You are talking about two entirely different things.

Maybe someone who does storage management and/or database management will have a different point of view.
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mframes

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PostPosted: Fri Apr 30, 2004 10:22 am    Post subject:
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superk ,
atleast give me the advantages and disadvantages of VSAM over other access methods ?
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anuradha

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Joined: 06 Jan 2004
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PostPosted: Fri Apr 30, 2004 6:29 pm    Post subject: vsam advantages
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Hello mframes,

Vsam is one coherent file storage system used to store and retrieve data.It is not a database management system like IDMS or DB2.It does not provide for relationships among the data.The existing databases like IMS or DB2 may be implemented using VSAM

If you see the advantages........

VSAM provides protection of data against unauthorized access through password facility
Cross-system (MVS & VSE) compatibility.VSAM datasets can be imported ans exported in MVS and VSE systems.
Also DEVICE Independence(Access via catalog).

Check out this link for some comparison (IAM vs. VSAM)

http://www.bmc.com/technews/003/IAMvsVSAM.html

hope this helps.

Thanks,
Anu
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mframes

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PostPosted: Mon May 03, 2004 11:51 am    Post subject:
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anu,
thanx for the info
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prasanth_thavva

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PostPosted: Thu Sep 08, 2005 11:09 am    Post subject: vsam and db2
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vsam is virtual access storage method its access method to retrieve data and orgnaize data..
db2 data base manage
if u query the table
select * from table;
it first pass control to db2 db2 fetches the data ... gives control to the vsam
vsam fetches the data and returns to db2.. so we dont know the internal accessing ...
interm given access to vsam only
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amalli

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PostPosted: Thu Sep 08, 2005 12:14 pm    Post subject: what are the advantages and disadvantages of VSAM ?
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vsam is virtual access storage method its access method to retrieve data and orgnaize data.
ESDS,KSDS,LDS,RRDS are the datasets of VSAM

dB2 IS RELATIONAL DATABASE MANAGEMENT SYSTEM.
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nitin_agr

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PostPosted: Fri Sep 09, 2005 12:08 am    Post subject:
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Advantages of using VSAM

? One method to support all types of data retrieval (KSDS, ESDS etc.)
? Can be a stand alone file or within a DBMS
? Supports fixed and Variable Records
? One utility, IDCAMS, to manage everything (IEBGENER for seq files, IEBCOPY for PDS, IEBISAM for ISAM files)
? Supports alternate index
? Device Independence (EXPORT and IMPORT)
? Portable across systems
? Modular, catalog contains all the information
? Catalogs are protected by internal security


Disadvantages of VSAM

? Require lot of DASD space
? For KSDS, primary key cannot be changed
? Performance can be slow because of complexity of Index
? Only resides on DISK
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