A journal receiver holds journal entries that you might use for recovery and entries that the system might use for recovery. For example, you might use record level entries, such as database record changes, and file level entries, such as the entry for opening or closing a file. Also, the system writes entries that you never see or use, such as entries for explicitly journaled access paths, for SMAPP, or for commitment control.
When you create a journal with the Create Journal (CRTJRN) command, the Change Journal (CHGJRN) command, or iSeries™ Navigator, you can specify options that will limit the data that gets deposited into these journal entries, or increases the maximum allowable size for the journal receiver. These options are as follows:
- The RCVSIZOPT parameter of the CRTJRN command
- The RCVSIZOPT parameter of the CHGJRN command
- The Advanced Journal Attributes dialog box of iSeries Navigator
- The Journal Properties dialog box of iSeries Navigator
The following subtopics explain the benefits of some of the values for receiver size options.
Remove internal entries
When you specify to remove internal entries the system periodically removes internal journal entries from the attached journal receiver when it no longer needs them for recovery purposes. Removing internal entries may have a very slight impact on system performance, because the system has to manage these internal entries separately and periodically remove them.
To remove internal entries specify the RCVSIZOPT(*RMVINTENT) parameter. The iSeries Navigator equivalent to the RCVSIZOPT(*RMVINTENT) parameter is Remove internal entries in the Advanced Journal Attributes or Journal Properties dialog.
Specifying to remove internal entries has these benefits:
- It reduces the impact that SMAPP may have on journal receivers for user-created journals.
- It reduces the size of journal receivers that are on the system.
- It reduces the amount of time and media required to save journal receivers, because unnecessary entries are not saved.
- It reduces the time that it takes to apply journal entries, because the system does not have to evaluate unnecessary entries.
- It reduces the communications overhead if the remote journal function is being used because unnecessary entries are not sent.
Minimize fixed-length portion of entries
Minimizing the fixed-length portion of entries has the following effects:
- All information selectable by the FIXLENDTA parameter is not deposited in the entries.
- Minimizing the fixed-length portion of entries reduces auxiliary storage space and some CPU time as well.
- When you view journal entries with this information removed, the displayed value is *OMITTED, blanks, or zeros, depending on the type of data.
- To determine if a journal receiver was attached to a journal while minimizing the fixed-length portion of entries, use the Display Journal Receiver Attributes DSPJRNRCVA command display.
- Do not use minimize the fixed-length portion of entries if you require an audit trail.
- Minimizing the fixed-length portion of entries limits the selection criteria
you can use on the following:
- Apply Journaled Changes (APYJRNCHG) command
- Apply Journaled Changes Extend (APYJRNCHGX) command
- Compare Journal Images (CMPJRNIMG) command
- Display Journal (DSPJRN) command
- Receive Journal Entry (RCVJRNE) command
- Remove Journaled Changes (RMVJRNCHG) command
- Retrieve Journal Entry (RTVJRNE) command
- Retrieve Journal Entries (QjoRetrieveJournalEntries) API
- Minimizing the fixed-length portion of entries reduces the communications overhead if the remote journal function is being used because unnecessary data is not sent.
To minimize the fixed-length portion of entries specify RCVSIZOPT(*MINFIXLEN). The iSeries Navigator equivalent to RCVSIZOPT(*MINFIXLEN) is Minimize fixed portion of entries in the Advanced Journal Attributes or Journal Properties dialog.
If you are using minimizing the fixed-length portion of entries, you cannot use the FIXLENDTA parameter. See Fixed-length options for journal entries for more information about the FIXLENDTA parameter.
Maximum receiver-size options
Use the following options to specify the maximum allowable size for your journal receivers and to specify the largest allowable sequence numbers for journal entries. There is no iSeries Navigator equivalent to the following options.
RCVSIZOPT(*SYSDFT)
- Using RCVSIZOPT(*SYSDFT) is currently the same as specifying RCVSIZOPT(*RMVINTENT *MAXOPT2). This the default.
- RCVSIZOPT(*MAXOPT1)
- Use RCVSIZOPT(*MAXOPT1) to set the maximum size of a journal receiver attached to your journal to approximately one terabyte (1 099 511 627 776 bytes) and a maximum sequence number of 9 999 999 999. Additionally, the maximum size of the journal entry which can be deposited is 15 761 440 bytes.
- RCVSIZOPT(*MAXOPT2)
- Use RCVSIZOPT(*MAXOPT2) to set the maximum size of a journal receiver attached to your journal to approximately one terabyte (1 099 511 627 776 bytes) and a maximum sequence number of 9 999 999 999. However, with RCVSIZOPT(*MAXOPT2), the system can deposit a journal entry as large as 4 000 000 000 bytes.
- RCVSIZOPT(*MAXOPT3)
- Use RCVSIZOPT(*MAXOPT3) to set the maximum size of a journal receiver
attached to your journal to approximately one terabyte (1 099 511 627 776
bytes). In addition, with RCVSIZOPT(*MAXOPT3) the journal receiver can have
a maximum sequence number of 18 446 744 073 709 551 600.
With RCVSIZOPT(*MAXOPT3), the system can deposit a journal entry as large
as 4 000 000 000 bytes. You cannot save or restore these journal
receivers to any releases before V5R3M0. Nor can you replicate them to any
remote journals on any systems at a release before V5R3M0.
If you use RCVSIZOPT(*MAXOPT3) you must use the FROMENTLRG and TOENTLRG parameters to specify a journal entry sequence number larger than 9 999 999 999 when you perform the following commands:
- APYJRNCHG
- APYJRNCHGX
- CMPJRNIMG
- DSPJRN
- RCVJRNE
- RMVJRNCHG
- RTVJRNE
Recovery count
A value of *SYSDFT resets
the journal's recovery count to the system default journal recovery count.
The Work with journal attributes (WRKJRNA) command will indicate the Journal
recovery count on the panel display and in the printed output. A value of
*SYSDFT will be displayed if the system default journal recovery count is
being used.
The Retrieve Journal Information (QjoRetrieveJournalInformation) API will also return the Journal Recovery Count. A value of ‘0’ will be returned if the system default journal recovery count is being used.