What Is Meant By Dirty Read In Vsam?

1.	What Is Meant By Dirty Read In Vsam?
Answer» HIGH degree of CONCURRENT access to VSAM files is achieved by dirty READ - It is done by avoiding the complications associated with CI and CA splits - The dirty read protocol is summarized as: The VSAM file mandatorily be defined with cross-region SHARE POINTS 4. - The file allocation must be with DISP=SHR - ENQ must be followed for all operations of the files, for data set - Data set name is specified for ENQ name - Any string can be used for the ENQ gname - The user’s buffer must be refreshed with GET request, after obtaining a lock - No lock is held during a wait - DEQ function should be called at the end of all the file operations of enqueue.

Answer»

HIGH degree of CONCURRENT access to VSAM files is achieved by dirty READ - It is done by avoiding the complications associated with CI and CA splits - The dirty read protocol is summarized as:
The VSAM file mandatorily be defined with cross-region SHARE POINTS 4. - The file allocation must be with DISP=SHR - ENQ must be followed for all operations of the files, for data set - Data set name is specified for ENQ name - Any string can be used for the ENQ gname - The user’s buffer must be refreshed with GET request, after obtaining a lock - No lock is held during a wait - DEQ function should be called at the end of all the file operations of enqueue.

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