Dependent write

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Dependent Write: A dependent write is a data update that is not to be physically written or committed until a previous update has been successfully completed. This is a principle means of providing data consistency for computer write I/O operations.

In the large systems environments, the logic that determines the sequence in which systems issue “writes” is controlled by the application processing flow and supported by basic system functions. Usually, when data is to be written, control is passed from the application program to system subroutines to perform the actual write. Once the write has completed, control is returned to the application and processing continues.

This process provides an inherent synchronization and guarantees that record A has been successfully written before the write I/O of record B can be issued by the application.

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