LISTCAT ALL Output Listing for a Non-VSAM Tailored Compressed Data Set

The following example illustrates the output produced for a non-VSAM tailored compressed data set. Tailored compression (used only with non-VSAM compressed data sets) creates dictionaries tailored specifically to the initial data written to the data set. Once derived, the dictionary is stored within the data set. This technique improves compression ratios over generic DBB compression.

Note: The following information is not an intended programming interface. It is provided for diagnostic purposes only.

The first byte of the dictionary token indicates the type of compression used for the data set.

X'100. ....': indicates compression has been rejected for the data set. No data is compressed.
X'010. ....': indicates generic DBB compression is used.
X'011. ....': indicates tailored compression is used.

Figure 1. Example of LISTCAT ALL Output for a Non-VSAM Tailored Compressed Dataset

     LISTCAT LEVEL(ZTAMS002) ALL
 NONVSAM ------- ZTAMS002.COMPRS.DATA01
      IN-CAT --- SYS1.MVSRES.MASTCAT
      HISTORY
        DATASET-OWNER-----(NULL)     CREATION--------2004.297
        RELEASE----------------2     EXPIRATION------0000.000
        ACCOUNT-INFO-----------------------------------(NULL)
        EATTR--------------(OPT)
      SMSDATA
        STORAGECLASS ---S1P03S12     MANAGEMENTCLASS---(NULL)
        DATACLASS ------SRX00001     LBACKUP ---0000.000.0000
      VOLUMES
        VOLSER------------1P0301     DEVTYPE------X'3010200F'
 FSEQN------------------0
        VOLSER------------1P0302     DEVTYPE------X'3010200F'
 FSEQN------------------0
      ASSOCIATIONS--------(NULL)
      ATTRIBUTES
        VERSION-NUMBER---------1
        STRIPE-COUNT-----------2

 ACT-DIC-TOKEN----X'6200000B000000000000000000000000000000000000000000000000000
 0000000000000'
        COMP-FORMT      EXTENDED
      STATISTICS
        USER-DATA-SIZE--------------------------------4509920
 COMP-USER-DATA-SIZE----------------------------351227
        SIZES-VALID--------(YES)