In this example, two input partitioned data sets (DATASET5 and DATASET6) are copied to an existing output partitioned data set (DATASET1). In addition, all members on DATASET6 are copied; members on the output data set that have the same names as the copied members are replaced. After DATASET6 is processed, the output data set (DATASET1) is compressed in place. Figure 1 shows the input and output data sets before and after processing.

Figure 1. Compress-in-Place Following Full Copy with “Replace” Specified

  //COPY     JOB  ...
  //JOBSTEP  EXEC PGM=IEBCOPY
  //SYSPRINT DD  SYSOUT=A
  //INOUT1   DD  DSNAME=DATASET1,UNIT=disk,VOL=SER=111112,
  //             DISP=(OLD,KEEP)
  //IN5      DD  DSNAME=DATASET5,UNIT=disk,VOL=SER=111114,
  //             DISP=OLD
  //IN6      DD  DSNAME=DATASET6,UNIT=disk,VOL=SER=111115,
  //             DISP=(OLD,KEEP)
  //SYSUT3   DD  UNIT=SYSDA,SPACE=(TRK,(1))
  //SYSUT4   DD  UNIT=SYSDA,SPACE=(TRK,(1))
  //SYSIN    DD  *
  COPYOPER COPY  OUTDD=INOUT1,INDD=(IN5,(IN6,R),INOUT1)
  /*

The control statements are discussed below:

• INOUT1 DD defines a partitioned data set (DATASET1), which contains three members (A, B and F).
• IN5 DD defines a partitioned data set (DATASET5), which contains two members (A and C).
• IN6 DD defines a partitioned data set (DATASET6), which contains three members (B, C and D).
• SYSUT3 and SYSUT4 DD define temporary spill data sets. One track is allocated for each on a disk volume.
• SYSIN DD defines the control data set, which follows in the input stream. The data set contains a COPY statement.
• COPY indicates the start of the copy operation. The OUTDD operand specifies DATASET1 as the output data set.

  The INDD operand specifies DATASET5 as the first input data set to be processed. It then specifies DATASET6 as the second input data set to be processed. In addition, the replace option is specified for all members copied from DATASET6. Finally, it specifies DATASET1 as the last input data set to be processed. Since DATASET1 is also the output data set, DATASET1 is compressed in place. However, if DATASET1 is a PDSE, the compress-in-place operation will not be processed.

  Processing occurs as follows:

  1. Member A is not copied from DATASET5 into DATASET1 because it already exists on DATASET1 and the replace option was not specified for DATASET5.
  2. Member C is copied from DATASET5 to DATASET1, occupying the first available space.
  3. All members are copied from DATASET6 to DATASET1, immediately following the last member. Members B and C are copied even though the output data set already contains members with the same names because the replace option is specified on the data set level.

  The pointers in DATASET1's directory are changed to point to the new members B and C. Thus, the space occupied by the old members B and C is unused. The members currently on DATASET1 are compressed in place, thereby eliminating embedded unused space.