How the system updates changed object information with the SAVCHGOBJ command

The changed object information kept by the system is a date and a timestamp. When the system creates an object, the system places a timestamp in the changed field. Any change to the object causes the system to update the date and timestamp.

Use the DSPOBJD command and specify DETAIL(*FULL) to display the date and time of the last change for a specific object. Use the Display File Description (DSPFD) command to display the last change date for a database member.

To display the last change date for a document library object, do the following:

  1. Use the Display DLO Name (DSPDLONAM) command to display the system name for the DLO and the ASP where it is located.
  2. Use the DSPOBJD command, specifying the system name, the name of the document library for the ASP (such as QDOC0002 for ASP 2), and DETAIL(*FULL).

Some common operations that result in a change of the date and time are:

  • Create commands
  • Change commands
  • Restore commands
  • Add and remove commands
  • Journal commands
  • Authority commands
  • Moving or duplicating an object

These activities do not cause the system to update the change date and time:

  • Message queue. When the system sends a message or when the system receives a message.
  • Data queue. When the system sends an entry or when the system receives and entry.

When you IPL, the system changes all of the job queues and output queues.

Change Information for Database Files and Members: For database files, the SAVCHGOBJ command saves the file description and any members that changed.

Some operations change the change date and time of the file and all of its members. Examples are the CHGOBJOWN, RNMOBJ, and MOVOBJ commands. If you save a file with 5 or more members, the system updates the change date for the library because it creates a recovery object in the library to improve save performance.

Operations that affect only the content or attributes of a member change only the date and time of the members. Examples are:

  • Using the Clear Physical File Member (CLRPFM) command
  • Updating a member by using source entry utility (SEU)
  • Updating a member with a user program.

The SAVCHGOBJ command can be useful for backing up typical source files. Normally, a source file has many members, and only a small percentage of members change every day.