Whats the use of SHAREOPTION in vsam

mkssampathkumar · New User Joined: 31 Aug 2006 Posts: 57 Location: chennai

Hi
Whats the use of shareoption in VSAM file

William Thompson · Posted: Wed Feb 21, 2007 6:25 pm

It is used to define the degree of sharing or exclusiveness for the dataset.

mkssampathkumar · New User Joined: 31 Aug 2006 Posts: 57 Location: chennai

Hi william.
Thanks for ur reply.

Am the beginner for mainframe.
The definition which is given by u in the high level(not only this post).
Some guys are giving a reply with good examples also.
Even this one line reply will not give any useful information abt SHAREOPTION.
In SHAREOPTION,there are 2 parameters are there.Whats the use of those parameters.

somnath · New User Joined: 21 Mar 2005 Posts: 18 Location: India

The SHAREOPTIONS parameter specifies how the component or cluster can be shared among
users within one system or across systems.

Syntax:
SHAREOPTIONS (Cross-region-value Cross-system-val)
The Cross-region option helps in concurrent data access on a stand-alone system ex: TSO&CICS
The Cross-system helps in data access for multiple computers (Two different computers that are interconnected)
The default is:
SHAREOPTIONS (1 3)
The values of the various possible values for the above are mentioned below with their meanings:
1.Multiple jobs can read only if no update takes place - Complete data integrity
2.Multiple jobs can read and at the same time one job can update - Write, but not read integrity
3.Multiple jobs can read & write simultaneously - No integrity
4.Same as option 3, but refreshes buffer after every read
The Share options 1 & 2 are not allowed for cross-system. For cross-region sharing, each batch job must
have DISP=SHR. For cross system sharing DISP parameter in the JCL is immaterial.

mkssampathkumar · New User Joined: 31 Aug 2006 Posts: 57 Location: chennai

Hi
Thanks for ur reply.Its very helpful for me