Previous Topic: SyntaxNext Topic: Usage


Parameters

dmcl-name

Names the DMCL. Dmcl-name is a 1- to 8-character name assigned according to naming conventions described in 7.3, "Naming Conventions".

DEFAULT BUFFER buffer-name

Specifies the default buffer for the DMCL. Buffer-name must identify a database buffer defined in the dictionary and associated with the DMCL.

The default buffer is used for all files, unless overridden at the segment or file level.

Native VSAM: For more information about assigning buffers for native VSAM files, see the "Usage" topic in this section.

NULL

On an ALTER DMCL statement, removes the named buffer as the default buffer for the DMCL.

DBTABLE dbtable-name

Specifies the name of the database name table to be used with the DMCL at runtime.

NULL

Disassociates the database name table from the DMCL.

DATA SHARING

Specifies or removes attributes associated with data sharing operations.

Data sharing attributes apply to any DC/UCF system that uses this DMCL and is a member of a data sharing group. If data sharing attributes are not included in the DMCL of a CA IDMS system that becomes a member of a data sharing group, the following defaults will be used:

data-sharing-attribute

LOCK ENTRIES lock-entry-count

Specifies the number of lock table entries that will be allocated within the coupling facility lock structure. The value specified must be in the range 4096 through 1,073,741,824. The number of lock entries will be rounded up to a power of 2.

MEMBERS member-count

Specifies the maximum number of CA IDMS systems that can be members of the system's data sharing group. The value specified must be in the range 7 through 247.

DEFAULT SHARED CACHE default-cache-name

Specifies the default shared cache for any system using this DMCL. Default-cache-name must identify an XES cache structure defined to a coupling facility accessible to the CA IDMS system.

The default shared cache for a system is used at runtime for any file whose area is designated as shared, if the file does not have an assigned cache. This value has no affect on files that are not associated with a shared area.

ON CONNECTIVITY LOSS

Specifies what action the CA IDMS system is to take when either a loss in connectivity to or a failure of a critical coupling facility structure associated with a data sharing group is detected.

NOABEND is the default if ON CONNECTIVITY LOSS is not specified.

MEMORY CACHE

Indicates global options for caching files in memory.

Note: For more information about operating-specific considerations in using memory cache and 64-bit storage, see the CA IDMS System Operations Guide.

LOCATION

Indicates where to allocate the storage for memory cache:

ANYWHERE

Memory cache storage is allocated from 64-bit storage; if no or not enough 64-bit storage is available, dataspace storage is acquired.

64 BIT ONLY

Memory cache storage is allocated from 64-bit storage; if no or not enough 64-bit storage is available, memory caching fails.

STORAGE LIMIT

Controls the amount of storage used for memory caching:

OPSYS

Memory cache storage can be acquired until the operating system limit is reached. For 64-bit storage, the operating system limit is set through the MEMLIMIT parameter; for dataspace storage, the limit is optionally imposed by an operating system exit.

nnn MB, GB, TB, PB, EB

CA IDMS controls the amount of memory cache storage if the value specified is smaller than the operating system limit. nnn must be a positive value between 1 and 32767. MB, GB, TB, PB, EB indicate the unit in which nnn is expressed. The abbreviations stand for Mega Byte (2**20), Giga Byte (2**30), Tera Byte (2**40), Peta Byte (2**50), and Exa Byte (2**60).

segment-specification

On an ALTER DMCL statement, specifies the name of a segment to be added to the DMCL, or identifies a segment in the DMCL to be altered or removed.

ADD

Adds the named segment to the DMCL definition or alters its attributes.

DROP

Drops the named segment from the DMCL definition.

SEGMENT segment-name

Identifies the segment. Segment-name is a 1- to 8-character value that identifies a segment defined to the dictionary.

DEFAULT BUFFER buffer-name

Specifies the buffer to be used by files associated with the segment. Buffer-name must identify a buffer associated with the DMCL. Unless overridden by a file override clause, all files associated with the segment will use the named buffer.

Native VSAM: For information about assigning buffers for native VSAM files, see the "Usage" topic in this section.

NULL

Removes the default buffer associated with the segment.

ON STARTUP SET STATUS TO

Specifies the default startup status for areas associated with the segment. The startup status determines how CA IDMS/DB accesses an area when the DC/UCF system is started after an orderly shutdown.

The status of an area determines the ready modes in which programs executing under the central version can obtain access to the area.

UPDATE

Sets the status of the area to update and places an external lock on the area.

When the status of an area is update, transactions executing under the central version can obtain access to the area in any ready mode.

ON STARTUP SET STATUS TO UPDATE is the default when you do not include the ON STARTUP parameter in a CREATE SEGMENT statement.

RETRIEVAL

Sets the status of the area to retrieval.

When the status of an area is retrieval, transactions executing under the central version can obtain access to the area in retrieval modes only (that is, transient retrieval, shared retrieval, protected retrieval, and exclusive retrieval).

TRANSIENT RETRIEVAL

Sets the status of the area to transient retrieval.

When the status of an area is transient retrieval, transactions executing under the central version can obtain access to the area only in retrieval ready modes, and regardless of the ready mode, no record or row locks will be acquired.

OFFLINE

Places the area offline.

When the status of an area is offline, transactions executing under the central version cannot obtain access to the area in any ready mode.

ON WARMSTART

Specifies the default warmstart status for areas associated with the segment. The warmstart status determines how CA IDMS/DB accesses an area when the DC/UCF system is started up after an abnormal termination.

MAINTAIN CURRENT STATUS

Sets the area status to that in effect at the time the DC/UCF system was abnormally terminated.

ON WARMSTART MAINTAIN CURRENT STATUS is the default when you do not include the ON WARMSTART parameter in a CREATE SEGMENT statement.

DEFAULT SHARED CACHE

Specifies or removes the default shared cache for a segment.

NULL is the default if DEFAULT SHARED CACHE is not specified.

The value established at the segment level may be overridden at the file level.

DATA SHARING

Specifies whether or not areas associated with the segment are eligible to be concurrently updated by CA IDMS systems that are members of a data sharing group.

NO is the default if DATA SHARING is not specified.

The value established at the segment level may be overridden for individual areas within the segment.

file-override-specification

On an ALTER DMCL statement, specifies override attributes for a file in a segment that has been added to the DMCL.

ADD

Adds or modifies file override information in the DMCL. ADD is the default.

DROP

Drops file override information from the DMCL.

Note: This parameter does not drop file definitions from the DMCL.

segment-name.file-name

Identifies the file whose attributes are being overridden. Segment-name must identify a segment included in the DMCL. File-name must identify a file in the named segment.

BUFFER buffer-name

Specifies the buffer for the file. Buffer-name must identify a buffer associated with the DMCL.

If no buffer is specified on a file override, the default buffer for the segment is used.

Native VSAM: For information about assigning buffers for native VSAM files, see the "Usage" topic in this section.

DEFAULT

Specifies that the file is to use the segment's default buffer. If the segment lacks a default buffer assignment, the default buffer is the default buffer assigned to the DMCL. DEFAULT is the default.

ASSIGN TO

Associates the database file with an external file name that overrides the external file name assigned on a CREATE or ALTER FILE statement. All external file names in a DMCL definition must be unique.

ddname

Specifies the external name for the file under z/OS or z/VM. Ddname must be a 1- through 8-character value that follows operating system conventions for ddnames.

filename

Specifies the external name for the file under z/VSE. Filename must be a 1- through 7-character value that follows operating system conventions for filenames.

DEFAULT

Removes the external file name override assigned to the file and re-assigns the external file name specified on a CREATE or ALTER FILE statement.

NULL

Removes any external file name for the file. If you specify NULL, you must specify the data set name on the DSNAME clause and/or z/VM VIRTUAL ADDRESS clause of the FILE statement. This option is not valid under z/VSE unless DYNAM/D is being used.

DISP

For z/OS and z/VM systems, specifies the disposition to be assigned when the file is dynamically allocated.

SHR

Indicates that the data set specified on the DSNAME parameter will be available to multiple DC/UCF systems and local mode transactions at a time.

Under z/VM, DISP SHR causes a link with an access mode of multiple read (MR).

OLD

Indicates that the data set specified on the DSNAME parameter will be available to only one DC/UCF system or local mode transaction at a time.

Under z/VM, DISP OLD causes a link with an access mode of multiple write (MW).

MEMORY CACHE NO

Specifies that a file is not to be cached in memory.

MEMORY CACHE YES

Specifies that a file is to be cached in memory.

Note: For more information about operating-system specific considerations in using memory cache and 64-bit storage, see the CA IDMS System Operations Guide.

DATASPACE NO

Same as MEMORY CACHE NO. This syntax is provided for upward compatibility only.

DATASPACE YES

Same as MEMORY CACHE YES. This syntax is provided for upward compatibility only.

SHARED CACHE

Specifies or removes the shared cache for a file.

DEFAULT is the default if SHARED CACHE is not specified.

area-override-specification

On an ALTER DMCL statement, specifies override attributes for an area in a segment that has been added to the DMCL.

ADD

Adds or modifies area override information in the DMCL. ADD is the default.

DROP

Drops area override information from the DMCL.

Note: This parameter does not drop area definitions from the DMCL.

segment-name.area-name

Identifies the area whose attributes are being overridden. Segment-name must identify a segment included in the DMCL. Area-name must identify an area in the named segment.

PAGE RESERVE SIZE reserve-character-count

Specifies the number of bytes to be reserved on each page to accommodate increases in the length of record occurrences or rows stored on the page. This clause overrides the value specified in the PAGE RESERVE SIZE clause of a CREATE or ALTER AREA statement.

Reserve-character-count must be either 0 or a multiple of 4 in the range 48 through 32,716 and must be less than or equal to the area's page size. The default is 0.

Native VSAM: For areas defined for native VSAM files, reserve-character-count must be 0.

ON STARTUP SET STATUS TO

Specifies a startup status for the area that overrides the startup status specified for the segment with which the area is associated. See above for a description of this clause and its options.

ON WARMSTART

Specifies a warmstart status for the area that overrides the warmstart status specified for the segment with which the area is associated. See above for a description of this clause and its options.

DATA SHARING

Specifies whether or not the area is eligible to be concurrently updated by CA IDMS systems that are members of a data sharing group.

DEFAULT is the default if DATA SHARING is not specified.

FOR

Specifies the operating system for which the DMCL is being generated. If not specified, the default is the operating system in which the GENERATE statement is executed.

MVS

Generates a DMCL load module for the z/OS operating system.

VSE

Generates a DMCL load module for the z/VSE operating system.

VM

Generates a DMCL load module for the z/VM operating system.

dmcl-load-module-name

Specifies the name of the DMCL load module to delete from the DDLCATLOD area.

PERMANENT

Physically erases the DMCL load module. By default, CA IDMS/DB logically erases the DMCL load module and physically erases it upon system startup.

AREas

On DISPLAY/PUNCH requests, identifies all database areas defined to the DMCL which have override specifications.

BUFfers

On DISPLAY/PUNCH requests, identifies all database buffers and journal buffers associated with the DMCL.

FILes

On DISPLAY/PUNCH requests, identifies all files defined to the DMCL which have override specifications.

JOUrnals

On DISPLAY/PUNCH requests, identifies all disk, tape, and archive journal files associated with the DMCL.

SEGments

On DISPLAY/PUNCH requests, identifies all segments contained in the DMCL.

DETails

Displays or punches details about the DMCL.

HIStory

Displays or punches:

ALL

Displays or punches all information about the DMCL. ALL is the default action for a DISPLAY or PUNCH verb.

NONe

Displays or punches the name of the DMCL.