DISK JOURNAL Statements

 
idms19
 
The DISK JOURNAL statements create, alter, drop, display, or punch the definition of a disk journal file from the dictionary.
Authorization
  • To create, alter, or drop a disk journal file, you must have the following privileges:
    • DBADMIN on the dictionary in which the disk journal file definition resides
    • ALTER on the DMCL with which the disk journal file is associated
  • To display or punch a disk journal file, you must have DISPLAY privilege on the DMCL with which the disk journal file is associated or DBADMIN on the dictionary in which the disk journal file definition resides.
Syntax
CREATE/ALTER DISK JOURNAL
►►─┬─ CREATE ─┬─ DISK JOURNAL ─┬──────────────┬─ journal-file-name ───────────►    └─ ALTER ──┘                └─ dmcl-name. ─┘    ►─┬────────────────────────────────┬─────────────────────────────────────────►    └─ FILE SIZE block-count blocks ─┘    ►─┬───────────────────────────────┬──────────────────────────────────────────►    └ ASSIGN TO ─┬─ ddname ─────────┤                 ├─ filename ───────┤                 └─ NULL ───────────┘    ►─┬────────────────────┬─────────────────────────────────────────────────────►    └┬─┬─ NONVSAM ◄──┬─┬─┘     │ └─ BDAM ──────┘ │     └─ VSAM ──────────┘  ►─┬─────────────────────────────┬────────────────────────────────────────────►    └─ DSNAME ─┬ 'data-set-name' ─┤               └─ NULL ◄──────────┘    ►─┬─────────────────┬────────────────────────────────────────────────────────►    └─ DISP ─ SHR ◄───┘    ►─┬──────────────────────────────────────────┬───────────────────────────────►    └─ VM VIRTUAL ADDRESS ─┬─ virtual-address ─┤                           └─ NULL  ◄──────────┘    ►─┬───────────────────────────┬──────────────────────────────────────────────►◄    └─ VM USERID ─┬ vm-user-id ─┤                  └─ NULL ◄─────┘
DROP DISK JOURNAL
►►── DROP DISK JOURNAL ─┬──────────────┬─ journal-file-name ──────────────────►◄                         └─ dmcl-name. ─┘
DISPLAY/PUNCH DISK JOURNAL
►►─┬─ DISplay ─┬─ DISK JOURNAL ─┬──────────────┬─ journal-file-name ──────────►    └─ PUNch ───┘                └─ dmcl-name. ─┘      ┌───────────────────────────────────────┐  ►─▼─┬───────────────────────────────────┬─┴──────────────────────────────────►      │               ┌────────────────┐  │      ├─ WITh ──────┬─▼─┬─ DETails ──┬─┴──┘      └─ WITHOut ───┘   ├─ HIStory ──┤                        ├─ ALL ◄─────┤                        └─ NONe ─────┘  ►─┬────────────────────────┬─────────────────────────────────────────────────►    └─ VERb ─┬─ DISplay ───┬─┘             ├─ PUNch ─────┤             ├─ CREate ◄───┤             ├─ ALTer ─────┤             └─ DROp ──────┘    ►─┬───────────────────────┬──────────────────────────────────────────────────►◄    └─ AS ─┬─ COMments ◄──┬─┘           └─ SYNtax ─────┘
 
Parameters
 
  • dmcl-name
    Identifies the DMCL with which the disk journal file is associated.
    Dmcl-name
    must name an existing DMCL defined to the dictionary. If you don't specify a DMCL name, you must establish a current DMCL as described in 7.3.3, "Entity Currency" earlier in this section.
  • journal-file-name
    Specifies the name of the journal file.
    Journal-file-name
    must be a 1- through 18-character name that follows the conventions described in 7.3, "Naming Conventions".
    Journal-file-name
    must be unique among the disk and archive journal file names within the DMCL definition.
  • FILE SIZE
    block-count
    Specifies the number of blocks in the journal file. This clause is required on a CREATE statement.
    Block-count
    is an integer in the range 9 through 2,147,483,647.
  • ASSIGN TO
    Specifies an external file name. Every external file name in a DMCL definition must be unique. In z/VSE without DYNAM/D, an external file name must be specified. In other environments, if the external file name is not specified, a data set name or VM virtual address must be specified.
  • ddname
    (z/OS and z/VM systems only) Specifies the external name for the file.
    ddname
    must be a 1- through 8-character value that follows operating system conventions for ddnames.
  • filename
    (z/VSE systems only) Specifies the external name for the file.
    filename
    must be a 1- through 7-character value that follows operating system conventions for file names.
  • NULL
    Sets the external file name to blanks. It is equivalent to not specifying an external file name for a file. This option is not valid under z/VSE unless DYNAM/D is being used.
  • NONVSAM
    Identifies the access method for the journal file as BDAM, or DAM. BDAM is a synonym for NONVSAM. NONVSAM is the default.
    The access method you specify must be the same for all disk journal files associated with the DMCL.
  • VSAM
    Identifies the access method for the journal file as VSAM. The access method you specify must be the same for all disk journal files associated with the DMCL.
  • DSNAME
    data-set-name
    Specifies the name of the data set to be used when dynamically allocating the journal file for z/OS, z/VSE, and OS-format data sets under z/VM.
    data-set-name
    must conform to host operating system rules for forming data set names.
    A
    data-set-name
    that includes embedded periods must be enclosed in single or double quotation marks.
    Under z/VM, the DSNAME parameter or VM VIRTUAL ADDRESS and USERID parameters, or both can be specified.
  • NULL
    Sets the data set name to blanks. This is equivalent to not specifying a data set name for a file.
  • DISP
    (z/OS and z/VM systems only) Specifies the disposition to be assigned when the file is dynamically allocated.
  • SHR
    Indicates that the data set used for the file is available to a DC/UCF system and multiple local mode applications at a time.
    Under z/VM, DISP SHR causes a link with an access mode of multiple read (MR).
    SHR is the default when you do not include the DISP parameter in a CREATE JOURNAL FILE statement.
  • VM VIRTUAL ADDRESS '
    virtual-address
    '
    (z/VM systems only) Specifies the virtual address of the minidisk used for the journal file.
    virtual-address
    is a hexadecimal value in the range X'01' to X'FFFF'.
  • NULL
    Sets the virtual address to blanks. On CREATE statements, this is equivalent to not specifying a virtual address for a file. On ALTER statements, it removes any previous virtual address specification for the file.
  • VM USERID
    vm-user-id
    (z/VM systems only) Identifies the owner of the minidisk used for the journal file.
    vm-user-id
    is a 1- to 8-character value.
    A user ID for an OS-format data set must be specified. The user ID is optional for CMS-format files.
    If a user ID is not specified for a CMS-format file, CA IDMS assumes that the owner of the minidisk is the user ID of the virtual machine in which it is running.
  • NULL
    On CREATE statements, this is equivalent to not specifying a minidisk owner for a file. On ALTER statements, removes any previous minidisk owner specification for the file.
  • DETails
    Displays or punches details about the disk journal.
  • HIStory
    Displays or punches:
    • The user who defined the disk journal
    • The user who last updated the disk journal
    • The date the disk journal was created
    • The date the disk journal was last updated
  • ALL
    Displays or punches all information on the disk journal. ALL is the default action for a DISPLAY or PUNCH verb.
  • NONe
    Displays or punches the name of the disk journal.
Usage
Define Two or More Disk Journal Files
You must define at least two disk journal files when you journal to disk. When one journal file is full, CA IDMS/DB switches to another one. You must use an ARCHIVE JOURNAL utility statement to offload the full journal file.
Dynamic Allocation of Journal Files
Dynamic allocation of files is operating system and file-type dependent. For more information on dynamic file allocation in various operating systems, see 7.14.3, “Usage".
Archive Journal File Requirement
When you journal to disk journal files, you must also define at least one archive journal file to which CA IDMS/DB offloads the contents of a disk journal when it is full.
Incompatibility of Tape and Disk Journal Files
You cannot include the definition of a tape journal file in the DMCL if you include the definitions of disk and archive journal files.
Disk Journaling Used Under the Central Version
To take advantage of the automatic recovery and warmstart capabilities offered under the central version, you must journal to disk.
Disk Journals in Local Mode
A DMCL containing disk journals can be used in local mode but no journaling of database activity is performed. To journal in local mode, use a DMCL that defines a tape journal file instead.
Block size of Disk Journal File
The block size of a disk journal file is determined by the page size of the journal buffer. For VSAM disk journals, the page size of the journal buffer must be the control interval size of the disk journal.
The block size or control interval of the disk journal file must not be larger than the block size of the archive journal file.
Dataspaces Not Supported
The use of dataspaces for journal files is not supported.
Examples
Defining a Disk Journal File
The following CREATE DISK JOURNAL statement defines the disk journal file SYSJRNL1:
create disk journal idmsdmcl.sysjrnl1    file size 1000 blocks    assign to sysjrnl1;
Dropping a Disk Journal File
The following DROP DISK JOURNAL statement deletes the definition of the disk journal file TMPJRNL1 from the dictionary:
drop disk journal idmsdmcl.tmpjrnl1;
More Information
 
  • On the procedure for defining disk journals, see Section5, "Defining, Generating, and Punching a DMCL".
  • On journaling procedures, such as offloading, see Section19, “Journaling Procedures".
  • On defining archive journal files, see 7.6, "ARCHIVE JOURNAL Statements".