Run the Snapshot Accessory

You must run Snapshot two times to clone a database, as follows:

  • First to create a parameter file for the database you specify
  • Second to actually perform the cloning

For subsequent runs of Snapshot, however, you can use the existing Snapshot parameter file for the database you are cloning. In other words, once you run Snapshot to create the parameter file, you do not need to create the parameter file again.

To replicate a DMSII database using Snapshot

  1. From CANDE, start Snapshot by entering one of the following commands. You must include the quotation marks.

    START WFL/DATABRIDGE/SNAPSHOT ("databasename" [,"logicaldatabasename"])

    For example:

    START WFL/DATABRIDGE/SNAPSHOT

    indicates that Snapshot should use the file (PROD)DESCRIPTION/INVENTORY ON DEVPACK.

    Where

    Is

    "databasename"

    The title of the DESCRIPTION file without the DESCRIPTION node. Quotation marks are required. The database name can include a usercode and pack, which are used to locate the database DESCRIPTION file, as follows:

    "(usercode)databasename ON packname"

    For example,
    ("(PROD)INVENTORY ON DEVPACK")
    creates a parameter file called DATA/SNAPSHOT/INVENTORY/CONTROL

    When you enter just a database name, Snapshot creates a parameter file named as follows:

    (usercode)DATA/SNAPSHOT/databasename/CONTROL ON familyname

    "logicaldatabasename"

    An optional name of a logical database when you want to do one of the following:

    • Clone the data sets and data items in the logical database instead of in the original database.
    • Create an alternate parameter file for the physical database, which is useful when you want to generate multiple support libraries for the same database but with different parameter files.

      When you enter a logical database name:

    • Snapshot uses DATA/SNAPSHOT/dbname/ldbname/CONTROL as the title of the parameter file, if it exists
    • Otherwise, Snapshot uses DATA/SNAPSHOT/ldbname/CONTROL as it did in previous releases, if it exists
    • Otherwise, if neither file exists, Snapshot creates one titled DATA/SNAPSHOT/dbname/ldbname/CONTROL

      The logical database name provides a means for having multiple parameter files for the same database. If ldbname is the name of a logical database within the dbname database, Snapshot uses that logical database. If not, it uses ldbname to specify an alternate parameter file.
  2. Use CANDE to edit the Snapshot parameter file to specify which data sets to clone and where to locate output files.
    • Modify the first part (Snapshot options) using the descriptions of the options listed in Snapshot Parameter File.
    • Modify the second part (each data set in the database) to reflect only the data sets you want to replicate. To do so, delete the comment sign (%) that precedes the name of the data set you want to clone.
  3. Run Snapshot again using the following syntax:

    START WFL/DATABRIDGE/SNAPSHOT ("databasename" [,"logicaldatabasename"])

    where databasename and logicaldatabasename indicate the name(s) you used in step 1.

    This time, Snapshot uses the Snapshot parameter file, clones the DMSII data, and outputs it according to the options you set.

  4. While Snapshot is working, you can display the number of records extracted and skipped as well as the current audit location and audit time by issuing an AX STATUS command. See Snapshot Commands for instructions.

    Note: If the following message appears, "DATABridge Engine: >>> [0027] datasetname does not have a set with a unique key <<<" and there are components of the data set that can form a unique key, you can create a primary key. See Creating a Primary Key for more information. Once you define the primary key, Snapshot will be able to clone the data set.

  5. Once the Snapshot accessory is finished, transport (download, copy to tapes, etc.) the DATA/SNAPSHOT/databasename/datasetname files or DATA/SNAPSHOT/logicaldatabasename/datasetname files to the client system and load the data into the target database.