How to Use

INIT CXX/FXX/IXX/LXX/WXX/Data Area › INIT IXX (Format Index Area) › How to Use

How to Use

To format an Index Area, execute DBUTLTY using the following command format:

►►─ INIT AREA=IXX,DBID=n ─┬───────────────────────┬─┬────────────────┬──►
                          └─ ,VERIFY= ─┬─ NO ◄ ─┬─┘ └─ BLKSIZE=size ─┘
                                       └─ YES ──┘

 ►─┬──────────────────────┬─┬───────────────┬─┬──────────────────┬──────►
   └─ OLDEP= ─┬─ YES ◄ ─┬─┘ └─ IXXAREA=aaa ─┘ └─ OPTION1=REINIT ─┘
              └─ NO ────┘
 ►─┬──────────────┬────────────────────────────────────────────────────►◄
   └─ ,VOLUMES=n ─┘

Command

INIT: Invokes the function to format areas for CA Datacom/DB use.

Required Keywords

AREA=IXX

Identifies the area to be formatted as the Index.

,DBID=

Identifies the database.

Valid Entries:: DATACOM-ID of the database
Default Value:: (No default)

Optional Keywords

,VERIFY=

If you do not specify the VERIFY= option, or if you specify VERIFY=NO (the default), an INIT opens the data set for output, builds a new control block, and initializes the extents.

If you specify VERIFY=YES, an INIT opens the data set for update, reads and updates an existing control block, and initializes the extents.

Because a new control block is always built with VERIFY=NO, specifying VERIFY=YES when the INIT is not for a new data set brings several benefits, including the following:

Because an existing control block is read and updated instead of a new one being built, the data area history (in the control block) documenting activities such as backups and loads is not lost. Data area history information can be a valuable aid when troubleshooting various problems.
VERIFY=YES prevents the unintentional overlaying of important information because of a JCL error, such as writing over files in PRODuction status that should have been in TEST status, or the inadvertent overlaying of the Directory (CXX) or Log Area (LXX).

Note: Even with VERIFY=YES specified, the last extent and the number of extents is lost during an initialize.

Valid Entries:: YES or NO
Default Value:: NO

BLKSIZE=size

This optional keyword allows you to select a block size other than the default. BLKSIZE= can be used to specify an index block size of from 4096 bytes through 8192 bytes. The BLKSIZE= value remains in effect until the next initialization of the IXX. You must pick an optimal size for your device type, in a manner similar to how the data area block size is selected. See the description of BLKSIZE= in the required keywords in How to Use. However, note that the index block size is subject to a user-provided default that is different than the DBUTLTY default using the DBIN1PR process with function DEFAULT and INIT_IXX_BLKSIZE=. Also note that the index block size is subject to a user-provided force of a specific value, even if BLKSIZE is specified using the DBIN1PR process with function FORCE and INIT_IXX_BLKSIZE= .

We do not recommend changing the block size from the default. For more information, see Controlling the Index Block Size.

Note: An OPEN error occurs if an attempt is made to open a database that has an index block size larger than the index buffer size. For more information about the ixxbfrsize parameter of the SYSPOOL MUF startup option, see the CA Datacom/DB Database and System Administration Guide.

Valid Entries:: 4096 through 8192
Default Value:: 4096 (or, for some device types, a little less)

OLDEP=

Refers to old entry points. When OLDEP=NO is specified, the DBNTRY entry point, designated as the primary entry point since the early 1980s, is the only entry point supported. For compatibility with prior versions, OLDEP=YES is the default, allowing the use of older entry points such as CBLDBMS and DATACOM. Those older entry points, however, use index blocks limited to a maximum of 255 entries. Specifying OLDEP=NO, to ensure that DBNTRY is used in Version 11.0, allows you to use index blocks that can hold a maximum of 8K entries. Therefore, if you want to use 8K index blocks, and for some performance enhancement, use OLDEP=NO.

Note: Do not initialize an index using the OLDEP= keyword until you are certain that the risk of needing to do a fallback to a prior version no longer exists. OLDEP= index initializations are not compatible with prior versions. If used in a prior version, an open error and a return code 43(43) NO VALID INDEX is received.

Alternately, if a program attempts using an old entry point with an index initialized as OLDEP=NO, the request fails with a return code 39(090) CANNOT PROCESS OLD REQUEST.

Valid Entries:

YES or NO

Default Value:

YES

However, note that the YES default value is subject to a user-provided default of INIT_IXX_OLDEP=NO. Therefore, if this option is important, review the output of the execution to see if the user override of the default occurred. For more information see the function DEFAULT and the information about INIT_IXX_OLDEP=NO.

IXXAREA=aaa

IXXAREA= is optional for databases that have a single Index Area IXX but, if specified, must be set as IXXAREA=IXX. IXXAREA= is required, however, for databases that have a Multi-Dataset Index and must be specified with one of the following: IXX, Inn (where nn can be 00 to 99), or *** where the *** (3 asterisks) means to initialize the IXX and then each additional index area in turn. The use of *** forces the same options for every area, including VERIFY=, BLKSIZE=, and OLDEP=.

Valid Entries:: IXX, I00 to I99, or ***
Default Value:: (No default)

,OPTION1=

You can specify REINIT (re-initialize) for the OPTION1= keyword during the initialization of an index area. Specifying OPTION1=REINIT requires that you also specify VERIFY=YES.

When using REINIT, the data set is re-initialized with the same number of tracks that were in use before the INIT, and no additional tracks are found or added to the data set during the INIT. When REINIT is not specified, the INIT closes the data set for update, opens the data set for output (and honors current, complete JCL specifications), closes the data set for output, and then reopens the data set for update.

Adding space to an index or data area is normally accomplished using an EXTEND function, but it can be done during an INIT function as well. A benefit of the OPTION1=REINIT for z/OS users is that REINIT allows unused volumes to be added to data sets that do not have to be removed before an INIT.

For example, if you are not using SMS, you could INIT an area on 3 volumes and load the area. You might then manually uncatalog the area and recatalog it with an additional volume or volumes. Those additional volumes would be available for any dynamic extend for the area that was needed, but to prevent the INIT from forcing the use of the volumes that were added solely for the use of dynamic extend, you would need to manually uncatalog the area before another INIT and recatalog it without any additional volumes.

Valid Entries:: REINIT
Default Value:: (No default)

,VOLUMES=n

(z/OS only)The n in VOLUMES=n is the maximum number of volumes to initialize. Without the VOLUMES= option, the number of volumes having specific VOLSER information is initialized. The VOLUMES= option allows more volumes to be catalogued as part of the data set and available to an EXTEND or dynamic EXTEND, while being effectively held in reserve without a specific allocation.

For example, you could specify VOLUMES=3 when using an INIT to initialize an area that needs 3 volumes, intending to only initialize the space on 3 volumes. But the JCL could specify 6 specific volumes, for example:

VOL=SER=(VOL001,VOL002,VOL003,VOL004,VOL005,VOL006)

In this example, volumes 4/5/6 are not allocated or used during the INIT but are available to a dynamic extend. In this case, the extra volumes would not need to be removed before another INIT.

Valid Entries:: the number n of volumes to be catalogued
Default Value:: (No Default)