IAMRECVR—DECOMPRESS command
The DECOMPRESS command allows a compressed backup of an IAM file to be decompressed in the event that IAM is not available. The IAM VSAM Interface (VIF) does not have to be active.
[ FROMDDNAME= ddname ] ,KEYLEN= nnn
,RKP=nnnnn [,SCAN]
[,TODDNAME= ddname ]
The following table describes the DECOMPRESS command operands. The minimal abbreviation for each operand keyword is underlined.
Operand | Description |
|---|---|
FROMDDNAME= | Defines the DDNAME of the compressed IAM backup file. The default is DISKIN. |
KEYLEN= | (Required) Specifies the length of the key within the data records in the IAM file This value can be obtained from an IAMINFO or LISTCAT report on the original IAM data set. |
RKP= | (Required) Specifies the relative location of the key within the data record in the IAM file This value can be obtained from an IAMINFO or LISTCAT report on the original IAM data set. |
SCAN | Reads a compressed backup file and all records decompressed, but an output file is not created. SCAN can be used to verify a compressed backup file. |
TODDNAME= | Defines the DDNAME of the output uncompressed flat file. The default is TAPEOUT. |
The following example displays the JCL and control card for decompress (EX4504A). Assume an IAM file with 100 byte records, an 8 byte key length with a relative key position (RKP) of 10 has been backed up by an IDCAMS REPRO with the BACKUPCOMPRESSED option, and is now needed in its uncompressed state.
//SYSPRINT DD SYSOUT=*
//DISKIND DD SN=my.seqfile,DISP=OLD
//TAPEOUT DD DSN=my.uncomp.seqfile,DISP=(,CATLG),
//DCB=(RE CFM=VB,LRECL=104,BLKSIZE=32760),UNIT=TAPE
//SYSIN DD*
DECOMPRESSKEYLEN=8,RKP=10
/*