Let's understand Mainframe
Home Tutorials Interview Q&A Quiz Mainframe Memes Contact us About us

Module 10: File processing

START statement

  • START statement is used to position the file pointer at a specific record location within indexed or relative file for subsequent sequential record retrieval
  • This statement can be used only for Indexed and Relative files which are opned either in INPUT or I-O mode.
  • Access mode of file must be sequential or dynamic. It cannot be coded for Random access
  • It establish the current location in the cluster for a READ NEXT statement.
  • It does not retrieve record; It only sets the current record pointer
  • Basic Syntax:-

    START file-name   [KEY IS  {IS EQUL TO/           IS = /           IS GREATER THAN /           IS >  /           IS NOT LESS THAN  /           IS NOT <  /           IS GREATER THAN OR EQUAL TO /           IS >=  }       key-data-name]   [INVALID KEY imperative-statement-1]   [NOT INVALID KEY imperative-statement-2] [END-START].

  • Where,
    • file-name is logical file name
    • KEY IS used to position file pointer at logical record in file whose key field satisfy the comparison
    • INVALID KEY imperative-statement-1 : This becomes true when record is not found for specified key and thus causes execution of imperative-statement-1
    • NOT INVALID KEY imperative-statement-2: This is used to specify statements to be executed when START operation succeeds

Example of START statement:-


© copyright mainframebug.com
Privacy Policy