Opening a File (ESDS, KSDS, or RRDS)

   How you code your OPEN statement for a VSAM file depends on whether the

   file is an empty file or a loaded file.

   To open a file that has never contained records (an empty file):

 |     Use OPEN OUTPUT for ESDS files.

     Use OPEN OUTPUT or OPEN EXTEND for KSDS and RRDS files.  (Either

     coding has the same effect.)  If you have coded the file for random or

     dynamic access, you can also use OPEN I-O if the file is optional.

   To open a file that already contains records (a loaded file):

       Use OPEN INPUT, OPEN I-O, or OPEN EXTEND

       °   For an ESDS or RRDS file opened EXTEND, the added records are

           placed after the last existing records in the file.

       °   For a KSDS file opened EXTEND, each record you add must have a

           record key higher than the highest record in the file.

   A file that once contained records, all of which have been deleted, can be

   opened as I-O or EXTEND.

   In every case, you should check the file status key after each OPEN statement.

Subtopics:

       1 Initially Loading a File Sequentially

       2 Initially Loading a File Randomly or Dynamically

       3 Loading a VSAM Data Set with Access Method Services

           

 Loading a VSAM Data Set with Access Method Services

   You can load or update a VSAM data set with the IDCAMS REPRO command.  See

   your Access Method Services Reference manual.  REPRO should be used

   whenever possible.