You can use the save changed object function to reduce the amount of save media that you use. You can also complete your save process in a shorter period of time.
Related reference:
“Determining when an object was last saved” on page 8
If a library contains an object, you can use the Display Object Description (DSPOBJD) command to find out when the system saved the object.
Related information:
Lotus Domino reference library
Saving Changed Objects (SAVCHGOBJ) command:
Use the Save Changed Objects (SAVCHGOBJ) command to save only those objects that have changed since a specified time.
The options for specifying objects, object types, and libraries are similar to those for the SAVOBJ command:
v You can specify up to 300 different libraries by using the LIB parameter. You can use specific or generic values.
v You can omit up to 300 libraries by using the OMITLIB parameter. You can specify generic values for this parameter.
v You can omit up to 300 objects by using the OMITOBJ parameter. You can specify generic values for this parameter.
Note: Use the Command user space (CMDUSRSPC) parameter on the save commands to specify up to 32767 names for the parameters.
You can perform multiple concurrent SAVCHGOBJ operations against a single library. This can be helpful if you need to save different parts of a library to different media devices simultaneously, as shown in the following example:
SAVCHGOBJ OBJ(A* B* C* $* #* @* ...L*) DEV(media-device-name-one) LIB(library-name) SAVCHGOBJ OBJ(M* N* O* ...Z*) DEV(media-device-name-two) LIB(library-name)
Saving changed objects in directories:
This information describes how to use the CHGPERIOD parameter of the SAV command to save objects that have changed.
You can use the change period (CHGPERIOD) parameter on the Save (SAV) command to save objects that changed since a specified time, objects that last changed during a specific time period, or objects that were changed since they were last saved.
If you specify CHGPERIOD(*LASTSAVE), you get any object that changed since any save operation you performed for that object with UPDHST(*YES) specified. If you use this method several times during a week, the resulting media will look like Table 23 on page 71.
To perform a save operation that includes all objects that changed since the last complete save of a directory (similar to what is shown in Table 22 on page 70), do one of the following:
v Specify a date and time for the CHGPERIOD parameter.
v Specify UPDHST(*YES) for a complete save operation. Specify UPDHST(*NO) and CHGPERIOD(*LASTSAVE) when you save changed objects.
You can also use the SAV command to save objects that have not changed since a particular time by specifying CHGPERIOD(*ALL *ALL date time). This might be useful to archive old information before you remove it.
The system keeps a record of when it last changed the object. It also records whether it changed the object since the last save or not. The system does not store data for when it last saved the object.
Select option 8 on the Work With Object Links (WRKLNK) display to view the attributes that describe whether an object in a directory changed since you last saved it.
Note: If you use the operating system of a client workstation to save an object, the PC archive indicator will be set to 'No'. Since file systems accessed through the network system do not distinguish between save operations, the system archive indicator for those file systems will always match the PC archive indicator. Therefore, changed objects in the file systems accessed through the network system that have been saved by a client workstation save operation will not be saved by a save operation until they have been changed again.
The UPDHST parameter value controls updating of the system save history and PC save history:
v *NO - The system does not update the save history. The PC archive attribute and the system archive attribute do not change.
v *YES - The system updates the save history. For file systems that you access through the network server, the PC archive attribute is set to 'No'. For other file systems, the system archive attribute is set to 'No'.
v *SYS - The system updates the system save history. The system archive attribute is set to 'No'.
v *PC - The system updates the PC save history. The PC archive attribute is set to 'No'.
Related concepts:
“How the system updates changed object information with the SAVCHGOBJ command” on page 71 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.
“Using the Save (SAV) command” on page 77
This information explains how to use the SAV command with the OBJ parameter.
Saving changed document library objects:
You can use the Save Document Library Object (SAVDLO) command to save DLOs that have changed since a particular time.
When you specify SAVDLO DLO(*CHG), the default setting saves DLOs that changed since you saved all DLOs for that user ASP (SAVDLO DLO(*ALL) FLR(*ANY)). When you save changed DLOs, the system also saves the distribution objects in the QUSRSYS library, which are called unfiled mail.
Note: The system saves documents that a distribution (unfiled mail) refers to if they have changed since the last time that you saved them. If you have Version 3 Release 1 or later, the system does not save these documents when you specify DLO(*MAIL).
Related reference:
“Methods for saving IBM-supplied document library objects and folders” on page 99
This information describes common save methods for saving IBM-supplied document library objects.
Additional considerations for SAVCHGOBJ:
If you need to save changed objects as part of your save strategy, you must ensure that any partial save activity that occurs between your full save operations does not affect what you save with the
SAVCHGOBJ command.
If users occasionally save individual objects, you might want them to specify UPDHST(*NO). That prevents their save activity from having an impact on the overall SAVCHGOBJ strategy.
Note: The most common way to use the SAVCHGOBJ command is to specify REFDATE(*SAVLIB). If you have a new library that has never been saved, it is not saved when you specify SAVCHGOBJ
REFDATE(*SAVLIB).
Using SAVCHGOBJ–Example:
In a typical environment, you might use the SAVLIB command once a week and the SAVCHGOBJ command every day. Because the default for SAVCHGOBJ is from the last SAVLIB operation, the media that the SAVCHGOBJ command produces tends to grow during the week.
What follows shows an example of using SAVCHGOBJ during a typical week. Assume that you save the entire library on Sunday night and the SAVCHGOBJ command is used each evening during the week:
Table 22. SAVCHGOBJ Command: Cumulative
Day Files That Changed That Day Media Contents
Monday FILEA, FILED FILEA, FILED
Tuesday FILEC FILEA, FILEC, FILED
Wednesday FILEA, FILEF FILEA, FILEC, FILED, FILEF
Thursday FILEF FILEA, FILEC, FILED, FILEF
Friday FILEB FILEA, FILEB, FILEC, FILED, FILEF
If a failure occurred on Thursday morning, you would:
1. Restore the library from Sunday evening.
2. Restore all the objects from Wednesday's SAVCHGOBJ media volumes.
When you use this technique of saving everything that changed since the last SAVLIB, recovery is easier.
You need to restore only the media volumes from the most recent SAVCHGOBJ operation.
Changing the reference date and time:The default for the command is to save objects that have changed since the library was last saved using the SAVLIB command. You can specify a different reference date and time by using the reference date (REFDATE) and reference time (REFTIME) parameters on the SAVCHGOBJ command. This enables you to save only objects that have changed since the last SAVCHGOBJ operation.
This might reduce the amount of media and the time for the save operation. Here is an example:
Table 23. SAVCHGOBJ Command–Not Cumulative
Day Files That Changed That Day Media Contents
Monday FILEA, FILED FILEA, FILED
Tuesday FILEC FILEC
Wednesday FILEA, FILEF FILEA, FILEF
Thursday FILEF FILEF
Friday FILEB FILEB
You can restore the SAVCHGOBJ media from earliest to latest. Or you can display each media volume and restore only the latest version of each object.
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:
v Create commands v Change commands v Restore commands
v Add and remove commands v Journal commands
v Authority commands
v Moving or duplicating an object
These activities do not cause the system to update the change date and time:
v Message queue. When the system sends a message or when the system receives a message.
v 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:
v Using the Clear Physical File Member (CLRPFM) command v Updating a member by using source entry utility (SEU) v 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.
Related concepts:
“Saving changed objects in directories” on page 69
This information describes how to use the CHGPERIOD parameter of the SAV command to save objects that have changed.