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- ACCOUNT(account_info)
- Defines
up to 32 bytes of accounting information and user data for the data
set. It must be between 1 and 32 bytes, otherwise you will
receive an error message.
- account_info
- Is only supported for SMS-managed VSAM and non–VSAM data sets.
It is only used for the data set level (not member level) of PDSE/PDS.
Abbreviation: ACCT
- BUFFERSPACE(size)
- Specifies
the minimum space for buffers. If BUFFERSPACE is not coded, VSAM attempts
to get enough space to contain two data component control intervals
and, if the data is key-sequenced, one index component control interval.
If the data set being defined is a KSDS, and the BUFFERSPACE specified
is not large enough to contain two data and one index CIs, VSAM increases
the specified buffer space and completes the define. VSAM may also
increase index CISIZE and, if necessary, increase the buffer space
to accommodate the larger index CISIZE. - size
- The space for buffers. Size can
be given in decimal (n), hexadecimal (X'n'), or binary (B'n') form.
The BUFFERSPACE setting is ignored when the data set is opened
for VSAM RLS or DFSMStvs mode.
Note: The limitations of the bufferspace
value on how many buffers will be allocated is based on storage available
in your region, and other parameters or attributes of the data set.
Abbreviations: BUFSP or BUFSPC
- BWO(TYPECICS|TYPEIMS|NO)
- Use
this parameter if backup-while-open (BWO) is allowed for the VSAM
sphere. BWO applies only to SMS data sets and cannot be used with
TYPE(LINEAR).
If BWO is specified in the SMS data class, the
value defined is used as the data set definition, unless it has been
previously defined with an explicitly specified or modeled DEFINE
attribute. - TYPECICS
- Use TYPECICS to specify BWO in a CICS® or
DFSMStvs environment. For RLS processing, this activates BWO processing
for CICS, or DFSMStvs, or both.
For non-RLS processing, CICS determines
whether to use this specification or the specification in the CICS FCT.
Exception: If CICS determines that it will use
the specification in the CICS FCT,
the specification might override the TYPECICS or NO parameters.
Abbreviation: TYPEC
- TYPEIMS
- Use to enable BWO processing for IMS™ data
sets.
Abbreviation:TYPEI
- NO
- Use this when BWO does not apply to the cluster.
Exception: If CICS determines that it will use
definitions in the CICS FCT,
the TYPECICS or NO parameters might be overwritten.
- CATALOG(catname)
- Identifies
the catalog in which the cluster is to be defined. See Catalog Selection Order for DEFINE for the order in which catalogs are selected.
To specify catalog names for SMS-managed data sets, you must have
authority to the RACF® STGADMIN.IGG.DIRCAT
FACILITY class. See Storage Management Subsystem (SMS) Considerations for more
information. - catname/alias
- Names the catalog or an alias that can be resolved
to a catalog. For example, if alias ABCD relates to catalog SYS1.USERCAT,
then specifying either ABCD or SYS1.USERCAT will cause the cluster
to be defined in SYS1.USERCAT.
Abbreviation: CAT
If the catalog's volume is physically mounted, it is
dynamically allocated. Mount the volume as permanently resident or
reserved.
If the catalog's volume is physically mounted,
it is dynamically allocated. The volume must be mounted as permanently
resident or reserved.
Abbreviation: CAT
- CONTROLINTERVALSIZE(size)
- The
size of the control interval for the cluster or component.
For
linear data sets, the specified value in bytes is rounded up to a
4K multiple, up to a maximum of 32K. If the size is not specified,
the value specified in the data class that is assigned to the data
set is used. Otherwise a default value of 4K is used.
If CONTROLINTERVALSIZE
is given on the cluster level, it propagates to the component level
at which no CONTROLINTERVALSIZE has been specified.
The size
of the control interval depends on the maximum size of the data records
and the amount of buffer space you provide.
LSR/GSR buffering
technique users can ensure buffer pool selection by explicitly defining
data and index control interval sizes.
If CONTROLINTERVALSIZE
is not coded, VSAM determines the size of control intervals. VSAM
selects a control interval size for the data component that will optimize
direct access storage usage. It will then select an index control
interval size based on the number of data control intervals in the
data control area. If the override indicator in
Data Class is set ON, the user specified CISIZE in DEFINE command
will be overridden by the CISIZE in the DATACLAS. - size
- Indicates a cluster's
data and index component size..
If SPANNED is not used, the size
of a data control interval must be at least 7 bytes larger than the
maximum record length.
If the control interval specified is
less than maximum record length plus a 7-byte overhead, VSAM increases
the data control interval size to contain the maximum record length
plus the needed overhead.
If SPANNED is specified, the control
interval size can be less than the maximum record length. You can
select a size from 512 to 8K in increments of 512, or from 8K to 32K
in increments of 2K. When you choose a size that is not a multiple
of 512 or 2048, VSAM chooses the next higher multiple. For a linear
data set, the size specified is rounded up to 4096 if specified as
4096 or less. It is rounded to the next higher multiple of 4096 if
specified as greater than 4096.
The size of the index control interval is
the number of data control intervals in a data control area that need
indexing at the sequence set level of the index component. The size
of each entry depends on an average compression value for a user key.
The keys will compress to 1/3 of the length of the actual key value.
In some cases, the general compressed key length on which the algorithm
is based will be affected by the actual values and ordering of the
user key. The result is that each entry can occupy more space in the
index record than that provided. This may result in additional control
area splits and in all cases, wasted space in the data set. If after
loading the data sets, this condition exists; noted by more than anticipated
space to store the data set on the direct access device. You should
increase the index control interval size. The size can be increased
incrementally until it is felt that this condition no longer exists.
The guideline formula documented in the past is as follows:
(KEYLEN/2
) * DATA CI/CA less than or equal to INDEX CISIZE.
You should
be aware that this is only a guideline and does not take into account
the actual algorithm for determining the index control interval size
requirement. However, the 2:1 compression of key length in the above
formula provides some additional overhead over the actual 3:1 formula
used during the actual algorithm. Using the above formula can result
in an index control interval size that is too large. This may increase
I/O transfer time for each index component record, or it may be too
small to address the condition described above.
Refer to "Optimizing
VSAM Performance" in z/OS DFSMS Using Data Sets for
a discussion of control interval size and physical block size.
Abbreviations: CISZ
or CNVSZ
- DATACLASS(class)
- Identifies
the name, 1-to-8 characters, of the data class for the data set. It
provides the allocation attributes for new data sets. Your storage
administrator defines the data class. However, you can override the
parameters defined for DATACLASS by explicitly using other attributes.
See Understanding the Order of Assigned Data Set Attributes for the order of precedence
(filtering) the system uses to select which attribute to assign.
DATACLASS
parameters apply to both SMS- and non-SMS-managed data sets. If DATACLASS
is specified and SMS is inactive, DEFINE is unsuccessful.
DATACLASS
cannot be used as a subparameter of DATA or INDEX.
Abbreviation: DATACLAS
- [EATTR(NO | OPT)]
- A data set level attribute specifying whether
a data set can have extended attributes (format 8 and 9 DSCBs) and
optionally reside in EAS.
- NO
- No extended attributes. The data set can not have
extended attributes (format 8 and 9 DSCBs) and cannot reside in EAS.
This is the default behavior for non-VSAM data sets.
- OPT
- Extended attributes are optional. The data set can
have extended attributes (format 8 and 9 DSCBs) and can optionally
reside in EAS. This is the default behavior for VSAM data sets.
DFSMS does not provide an actual
default value for the EATTR attribute. If an EATTR attribute is not
specified on the DEFINE command, in the SMS DATA CLASS, JCL, dynamic
allocation parameters or MODEL data set, the EATTR value is recorded
as not being specified in the attributes for the data set.
For VSAM files a not specified value is treated by the
system as if OPT was specified for EATTR. For non-VSAM files a not
specified value is treated by the system as if NO was specified for
EATTR. A not specified value for EATTR is the setting for data sets
created prior to EAS support. When an EATTR attribute of not specified
is encountered during a DEFINE or end of volume (EOV) extend processing,
DFSMS internally performs the default action for the data set type
when creating the new extent location.
See DCOLLECT User Exit and Interpreting DCOLLECT Output for
collecting EATTR values stored in the volume table of contents (VTOC)
and SMS DATA CLASS. The cataloged EATTR value is provided in DCOLLECT
and LISTCAT.
- ERASE|NOERASE
- Specifies whether the cluster's components are to be erased when
its entry in the catalog is deleted.
- ERASE
- Overwrites
each component of the cluster with binary zeros when its catalog entry
is deleted. If the cluster is protected by a RACF generic or discrete profile and is cataloged,
you can use RACF commands to
specify an ERASE attribute. If you do this, the data component is
automatically erased upon deletion.
Abbreviation: ERAS
- NOERASE
- Specifies
that each component of the cluster is not to be overwritten with binary
zeros. NOERASE will not prevent erasure if the cluster is protected
by a RACF generic or discrete
profile that specifies the ERASE attribute and if the cluster is cataloged.
Use RACF commands to alter
the ERASE attribute in a profile.
Abbreviation: NERAS
- EXCEPTIONEXIT(entrypoint)
- Specifies
the name of a user-written exception-exit routine, that receives control
when an exceptional I/O error condition occurs during the transfer
of data between your program's address space and the cluster's DASD
space. An exception is any condition that causes a SYNAD exit to be
taken. The component's exception-exit routine is processed first,
then the user's SYNAD exit routine receives control. If an exception-exit
routine is loaded from an unauthorized library during access method
services processing, an abnormal termination occurs. See z/OS DFSMS Using Data Sets.
Abbreviation: EEXT
- FILE(ddname)
- Names
the DD statement that identifies and allocates the DASD and volumes
that must be available for space allocation on the volumes specified
by the VOLUMES keyword. If more than one volume is specified, all
volumes must be the same device type.
If data and index components
are to reside on separate devices, you can specify a separate FILE
parameter as a parameter of DATA and INDEX to point to different
DD statements.
If the FILE parameter is not specified, an attempt
is made to dynamically allocate the required volumes. The volume must
be mounted as permanently resident or reserved. When the FILE parameter
is used, the specified volumes are directly allocated before access
method services gets control.
An example DD statement is: //ddname DD UNIT=(devtype[,unitcount]),
// VOL=SER=(volser1,volser2,volser,...),DISP=OLD
Restriction: When
FILE refers to more than one volume of the same device type, the DD
statement that describes the volumes cannot be a concatenated DD statement.
- FREESPACE(CI-percent[
CA-percent]|0 0)
- Specifies
the percentage of each control interval and control area to be set
aside as free space when the cluster is initially loaded or when
a mass insert is done. CI-percent is a percentage of the amount of
space to be preserved for adding new records and updating existing
records with an increase in the length of the record. Since a CI is
split when it becomes full, the CA might also need to be split when
it is filled by CIs created by a CI split. The empty space in
the control interval and control area is available for data records
that are updated and inserted after the cluster is initially loaded.
This parameter applies only to key-sequenced clusters, and variable-length
relative records with variable-length records. CI-percent is
the number of bytes that is equal to, or slightly less than, the percentage
value of CI-percent. CA-percent is
the number of control intervals equal to, or less than, the percentage
of CA-percent.
CI-percent and CA-percent must
be equal to, or less than, 100. When you use FREESPACE(100 100), one
data record is placed in each control interval used for data. One
control interval in each control area is used for data (that is, one
data record is stored in each control area when the data set is loaded).
If you do not use FREESPACE, the default reserves no free space when
the data set is loaded. If the override indicator
in Data Class is set ON, the user specified CI-percent and CA-percent
of FREESPACE keyword in the DEFINE command will be overridden by the
CI-percent and CA-percent in the DATACLAS.
When you define
the cluster using the RECORDS parameter, the amount of free space
specified is not considered in the calculations to determine primary
allocation.
Abbreviation: FSPC
- FRLOG(ALL|NONE|REDO|UNDO)
- Specifies if VSAM batch logging can be performed for your VSAM
data set. VSAM batch logging is available with CICS VSAM Recovery V3R1.
There is no default
value for FRLOG. If FRLOG is left out, the data set cannot be used
for VSAM batch logging. See the ALTER command for enabling VSAM batch
logging after a data set is created.
- ALL
- Enables the changes made to your VSAM data set to be both backed
out and forward recovered using the VSAM logging. The LOGSTREAMID
parameter indicates the changes that are made by applications that
are written to the MVS™ log stream.
When specifying FRLOG(ALL), you must also specify LOGSTREAMID.
- NONE
- Indicates that the data set can be used for VSAM batch logging.
However, the function should be disabled. The LOGSTREAMID parameter
indicates changes that are made by applications that are written to
the MVS log stream. Specifying
FRLOG(NONE) implies that you may use the data set for RLS processing;
omitting it indicates that RLS processing will not occur.
- REDO
- Enables the VSAM batch logging function for your VSAM data set.
The LOGSTREAMID parameter indicates changes that are made by applications
that are written to the MVS log
stream. When specifying FRLOG(REDO), you must also specify LOGSTREAMID.
- UNDO
- Enables the changes made to your VSAM data set to be backed out
using the VSAM logging. The LOGSTREAMID parameter indicates changes
that are made by applications that are written to the MVS log stream.
Restrictions: - If you do not want VSAM batch logging for your data set, do not
specify the FRLOG parameter. If you specify FRLOG(NONE), the data
set must support VSAM batch logging, but logging is not in effect.
- If FRLOG is specified, the data set:
- Must be SMS-managed
- Cannot be LINEAR or a temporary data set
- INDEXED|LINEAR|NONINDEXED|NUMBERED
- Shows the type of data organization
for the cluster.
If you want a data organization other than INDEXED
(the default), you must explicitly use it with this parameter.
When
a cluster is defined, you indicate whether the data is to be indexed
(key-sequenced), nonindexed (entry-sequenced), numbered (relative
record), or linear.
Certain parameters apply only to key-sequenced
clusters, as noted in the description of each of these parameters.
Linear
data set clusters are treated as ESDS clusters that must be processed
using control interval access.
If you do not choose either
the data organization or the MODEL parameter, your cluster defaults
to key-sequenced (indexed).
If you want to define an entry-sequenced
or a relative record cluster, you must specify the NONINDEXED, the
NUMBERED, or the MODEL parameter.
The data organization you
select must be consistent with other parameters you specify. - INDEXED
- Shows that the cluster
being defined is for key-sequenced data. If INDEXED is specified,
an index component is automatically defined and cataloged. The data
records can be accessed by key or by relative-byte address (RBA).
Abbreviation: IXD
- LINEAR
- Specifies
that the cluster being defined is for linear data. Because linear
data set clusters are treated as ESDS clusters that must be processed
using control interval access, you can use most of the commands and
parameters you use to manipulate ESDS clusters. There are two exceptions:
- Parameters that refer to logical records are not allowed (except
RECORDS).
- Use partial printing by specifying the RBA syntax.
Space is allocated for a linear data set with the number
of control intervals equal to the number of records. Linear data sets
cannot be accessed for RLS processing. The LOG, LOGSTREAMID, and BWO
parameters do not apply to linear data sets.
Restriction: Linear
data sets cannot be accessed for VSAM RLS or DFSMStvs processing.
The LOG, LOGSTREAMID, and BWO parameters do not apply to linear data
sets.
Abbreviation: LIN
- NONINDEXED
- Indicates that the
cluster being defined is for entry-sequenced data. The data records
can be accessed sequentially or by relative-byte address (RBA).
Abbreviation: NIXD
- NUMBERED
- Specifies
that the cluster's data organization is for relative record data.
A relative record cluster, which is similar to an entry-sequenced
cluster, has fixed-length records or variable-length records that
are stored in slots. The RECORDSIZE parameter determines if the records
are fixed-length or variable-length. Empty slots hold space for records
to be added later. The data records are accessed by relative record
number (slot number).
Abbreviation: NUMD
- KEYS(length offset|64 0)
- Provides
information about the prime key field of a key-sequence data set's
data records.
This parameter overrides any KEYS specification
on the DATACLASS parameter.
This parameter applies only to
key-sequenced clusters. The default is a key field of 64 bytes, beginning
at the first byte (byte 0) of each data record.
The key field
of the cluster's index is called the prime key to distinguish it from
other keys, called alternate keys. See DEFINE ALTERNATEINDEX for
more details on how to choose alternate indexes for a cluster.
When
the data record spans control intervals, the record's key field must
be within the part of the record that is in the first control interval.
- length offset
- specifies the length of the key and its displacement (in bytes)
from the beginning of the record. The sum of length plus offset cannot
exceed the length of the shortest record. The length of the key can
be 1 to 255 bytes.
- LOG(NONE|UNDO|ALL)
- Establishes
whether the sphere to be accessed with VSAM record-level sharing (RLS)
or DFSMStvs is recoverable or non-recoverable. It also indicates whether
or not forward recovery logging should be performed for the data set.
LOG applies to all components in the VSAM sphere. VSAM uses LOG in
the following way:
- Nonrecoverable Sphere
- The sphere is considered nonrecoverable if LOG(NONE) is specified.
VSAM allows concurrent read and update sharing across multiple resource
managers and other applications.
- Recoverable Sphere
- The sphere is considered recoverable if LOG(UNDO) or LOG(ALL)
is specified. For a recoverable sphere, VSAM does not allow applications
that do not support commit and backout to open a data set in the sphere
for output using RLS access, but applications can open the sphere
for output using DFSMStvs access. The applications can, however, open
the sphere for RLS access for input processing only.
If LOG is specified in the SMS data class, the
value defined is used as the data set definition, unless it has been
previously defined with an explicitly specified or modeled DEFINE
attribute.
LOG cannot be used with LINEAR.
LOGSTREAMID
cannot be used with LINEAR. - NONE
- Indicates that neither an external backout nor a forward recovery
capability is available for the sphere accessed in VSAM RLS or DFSMStvs
mode. If you use LOG(NONE), RLS and DFSMStvs consider the sphere to
be nonrecoverable.
- UNDO
- Specifies that changes to the sphere accessed in VSAM RLS or DFSMStvs
mode can be backed out using an external log. RLS and DFSMStvs consider
the sphere to be recoverable when you use LOG(UNDO).
- ALL
- Specifies that changes to the sphere accessed in RLS and DFSMStvs
mode can be backed out and forward recovered using external logs.
DFSMStvs and RLS consider the sphere recoverable when you use LOG(ALL).
When you specify LOG(ALL), you must also specify the LOGSTREAMID parameter.
VSAM RLS and DFSMStvs allow concurrent read or update sharing
for nonrecoverable spheres through commit (CICS) and noncommit protocol applications. For
a recoverable sphere, a noncommit protocol application must use DFSMStvs
to be able to open the sphere for update using RLS access.
- LOGREPLICATE|NOLOGREPLICATE
- Identifies whether or not the VSAM data set being define is eligible
for VSAM replication.
- LOGREPLICATE
- VSAM data set is eligible for VSAM replication. The update will
be captured in the replication log identified by the LOGSTREAMID parameter.
When LOGREPLICATE is specified, LOGSTREAMID must also be specified.
LOGREPLICATE does not apply to LINEAR data sets.
Abbreviation: LOGR
- NOLOGREPLICATE
- VSAM data set is not eligible for VSAM replication.
NOLOGREPLICATE does not apply to LINEAR data sets.
Abbreviation: NOLOGR
If neither LOGREPLICATE nor NOLOGREPLICATE
is specified, the value is: - The value of the model object, if there is a model specified for
the DEFINE
- The value of the SMS DATACLAS, if there is no model for the defined
object
- NOLOGREPLICATE, if there neither a model for the DEFINE nor SMS
DATACLAS has been specified.
- LOGSTREAMID(logstream)
- Gives
the name of the forward recovery log stream. It applies to all components
in the VSAM sphere.
If LOGSTREAMID is specified in the SMS data
class, the value defined is used as the data set definition, unless
it has been previously defined with an explicitly specified or modeled
DEFINE attribute. - logstream
- The name of the forward recovery log stream. This can be a fully
qualified name up to 26 characters, including separators. If LOG(ALL)
is specified, LOGSTREAMID(name) must be specified.
Abbreviation:LSID
- MANAGEMENTCLASS(class)
- For
SMS-managed data sets: Specifies the name, 1-to-8 characters,
of the management class for a new data set. Your storage administrator
defines the names of the management classes you can use. If MANAGEMENTCLASS
is not used, but STORAGECLASS is used or defaulted, MANAGEMENTCLASS
is derived from automatic class selection (ACS). If MANAGEMENTCLASS
is specified and STORAGECLASS is not specified or derived,
the DEFINE is unsuccessful. If SMS is inactive and MANAGEMENTCLASS
is specified, the DEFINE will be unsuccessful. MANAGEMENTCLASS cannot
be listed as a subparameter of DATA or INDEX.
Abbreviation:MGMTCLAS
- MODEL(entryname[ catname])
- Specifies
an existing entry to be used as a model for the entry being defined.
See Understanding the Order of Assigned Data Set Attributes for information on how
the system selects modeled attributes.
A VVDS cannot be modeled.
DATACLASS,
MANAGEMENTCLASS, and STORAGECLASS attributes are not modeled.
You
can use an existing cluster's entry as a model for the attributes
of the cluster being defined. For details about how a model is used,
see z/OS DFSMS Managing Catalogs.
You
can use some attributes of the model and override others by explicitly
specifying them in the definition of the cluster or component. If
you do not want to add or change any attributes, you need specify
only the entry type (cluster, data, or index) of the model to be used
and the name of the entry to be defined.
See Understanding the Order of Assigned Data Set Attributes for more information about the order
in which the system selects an attribute.
When you use a cluster
entry as a model for the cluster, the data and index entries of the
model cluster are used as models for the data and index components
of the cluster still to be defined, unless another entry is specified
with the MODEL parameter as a subparameter of DATA or INDEX. - entryname
- specifies the name of the cluster or component entry to be used
as a model.
- OWNER(ownerid)
- Identifies
the cluster's owner.
For TSO/E users, if the owner is not identified
with the OWNER parameter, the TSO/E user's userid becomes the ownerid.
- RECATALOG|NORECATALOG
- Indicates whether the catalog entries for the cluster components
are to be re-created from information in the VVDS.
- RECATALOG
- Recreates the catalog
entries if valid VVDS entries are found on the primary VVDS volume.
If they are not, the command ends.
When recataloging
entries (including zFS files) with indirect volsers, the VVDS on the
substituted volser must contain a valid NVRs or VVRs that match the
entry name.
Catalog entries can be re-created only in
the catalog specified in the VVR except for entries that are swap
space, page space, or SYS1 data sets.
The RECORDSIZE parameter
is required when doing a DEFINE RECATALOG of a variable-length relative
record data set (VRRDS).
Identification of RECATALOG requires
that NAME, INDEXED, LINEAR, NONINDEXED, NUMBERED, and VOLUMES be used
as they were when the cluster was originally defined. If you specify
RECATALOG, you are not required to use CYLINDERS, RECORDS, or TRACKS.
If
ATTEMPTS, AUTHORIZATION, CATALOG, CODE, MODEL, or OWNER parameters
are used during the original define, they must be respecified with
RECATALOG to restore their original values; otherwise, their default
values are used.
When you use the TO parameter with RECATALOG,
only the cluster's expiration date is updated. The DATA and INDEX
components are not updated.
If the RACF user has ADSP specified, a profile is defined
to RACF for the data set being
re-cataloged.
If the cluster was SMS-managed, the volume serials
should be the same as the volumes actually selected by SMS.
The
catalog for the entries being re-created must have the same name as
the catalog that contained the original entries.
Abbreviation: RCTLG
- NORECATALOG
- Indicates
that the catalog entries are not re-created from VVDS entries. Catalog
entries are created for the first time.
Abbreviation: NRCTLG
- RECORDSIZE(average maximum|default)
- Specifies
the average and maximum lengths, in bytes, of the records in the data
component. The minimum record size is 1 byte.
RECORDSIZE can be
given as a parameter of either CLUSTER or DATA.
This parameter
overrides the LRECL specification on the DATACLASS parameter.
For
nonspanned records, the maximum record size + 7 cannot exceed the
data component's control
interval size (that is, the maximum nonspanned record size, 32 761,
+ 7 equals the maximum data component control interval size, 32 768).
When
you use a record size that is larger than one control interval, you
must also specify spanned records (SPANNED). The formula for the maximum
record size of spanned records as calculated by VSAM is as follows:
MAXLRECL = CI/CA * (CISZ - 10)
where:
- MAXLRECL is the maximum spanned record size.
- CI/CA represents the number of control intervals per control area.
- CISZ is the control interval size.
When you select NUMBERED, you identify a data set as
a relative
record data set. If you use NUMBERED and select the same value for
average as for maximum, the relative records must be fixed-length.
If you specify NUMBERED and select two different values for the average
and maximum record sizes, the relative records can be variable-length.
If you know that your relative records are fixed-length, however,
be sure to define them as fixed-length. Performance is affected for
relative record data sets defined as variable-length. Each variable-length
relative record is increased internally in length by four.
When
your records are fixed length, you can use the following formula to
find a control interval size that contains a whole number (n) of records:
CISZ = (n x RECSZ) + 10
or
n = (CISZ - 10)
RECSZ
If you select SPANNED or NUMBERED
for your fixed-length records: CISZ =(n x (RECSZ + 3)) + 4
or
n = (CISZ - 4)
(RECSZ + 3)
where: - n is the number of fixed-length records in a control
interval.
- CISZ is the control interval size (see also the CONTROLINTERVALSIZE
parameter).
- RECSZ is the average record size.
- default
- When SPANNED is used, the default is RECORDSIZE(4086 32600). Otherwise,
the default is RECORDSIZE(4089 4089).
Example: REC(sec) x RECSZ(avg) > RECSZ(max)
- where:
- REC(sec) is the secondary space allocation quantity, in records.
- RECSZ(avg) is the average record size (default = 4086 or 4089
bytes).
- RECSZ(max) is the maximum record size (default = 4089 or 32600
bytes).
When the SPANNED record size default prevails (32600
bytes), the secondary allocation quantity should be at least 8 records.
Restriction: With
REPRO and EXPORT, you cannot use data sets with record sizes greater
than 32 760.
Abbreviation: RECSZ
- REUSE|NOREUSE
- Specifies whether or not the cluster can be opened again and again
as a reusable cluster.
If REUSE or NOREUSE is specified in the
SMS data class, the value defined is used as the data set definition,
unless it has been previously defined with an explicitly specified
or modeled DEFINE attribute. - REUSE
- Specifies
that the cluster can be opened again and again as a reusable cluster.
When a reusable cluster is opened, its high-used RBA is set to zero
if you open it with an access control block that specifies the RESET
attribute.
REUSE lets you create an entry-sequenced, key-sequenced,
or relative record work file.
When you create a reusable cluster,
you cannot build an alternate index to support it. Also, you cannot
create a reusable cluster with key ranges (see the KEYRANGE parameter).
Reusable data sets can be multivolume and can have up to 123 physical
extents.
Restriction: If you select REUSE and your command
also contains the keyword UNIQUE, you must remove the UNIQUE
keyword or the DEFINE command will be unsuccessful.
Abbreviation: RUS
- NOREUSE
- Indicates
that the cluster cannot be opened again as a new cluster.
Abbreviation: NRUS
- RLSQUIESCE | RLSENABLE
- Specifies whether the cluster's components are created in VSAM
record-level sharing (RLS) quiesce or enable mode.
- RLSQUIESCE
- The cluster component is defined in RLS quiesce mode, which is
the default.
- RLSENABLE
- The cluster component is defined in RLS enable mode.
Abbreviation: RLSQ RLSE
- SHAREOPTIONS(crossregion[ crosssystem]|1 3)
- Shows
how a component or cluster can be shared among users. However, SMS-managed
volumes, and catalogs containing SMS-managed data sets, must not be
shared with non-SMS systems. For a description of data set sharing,
see z/OS DFSMS Using Data Sets.
To ensure integrity, you should be sure that share options specified
at the DATA and INDEX levels are the same.
The value of SHAREOPTIONS
is assumed to be (3,3) when the data set is accessed in VSAM RLS or
DFSMStvs mode.
- crossregion
- Specifies the amount
of sharing allowed among regions within the same system or within
multiple systems using global resource serialization (GRS). Independent
job steps in an operating system, or multiple systems in a GRS ring,
can access a VSAM data set concurrently. For more information about
GRS, see z/OS MVS Planning: Global Resource Serialization. To share a data set, each user
must use DISP=SHR in the data set's DD statement. You can use the
following options:
-
- OPT 1
- The data set can be shared by any number of users for read processing,
or the data set can be accessed by only one user for read and write
processing. VSAM ensures complete data integrity for the data set.
This setting does not allow any non-RLS access when the data set is
already open for VSAM RLS or DFSMStvs processing. A VSAM RLS or
DFSMStvs open will fail with this option if the data set is already
open for any processing.
- OPT 2
- The data set can be accessed by any number of users for read processing,
and it can also be accessed by one user for write processing. It is
the user's responsibility to provide read integrity. VSAM ensures
write integrity by obtaining exclusive control for a control interval
while it is being updated. A VSAM RLS or DFSMStvs open is not allowed
while the data set is open for non-RLS output.
If the data set
has already been opened for VSAM RLS or DFSMStvs processing, a non-RLS
open for input is allowed; a non-RLS open for output fails. If the
data set is opened for input in non-RLS mode, a VSAM RLS or DFSMStvs
open is allowed.
- OPT 3
- The data set can be fully shared by any number of users. Each
user is responsible for maintaining both read and write integrity
for the data the program accesses. This setting does not allow any
non-RLS access when the data set is already open for VSAM RLS or DFSMStvs
processing. If the data set is opened for input in non-RLS mode,
a VSAM RLS or DFSMStvs open is allowed.
- OPT 4
- The data set can be fully shared by any number of users. For each
request, VSAM refreshes the buffers used for direct processing. This
setting does not allow any non-RLS access when the data set is already
open for VSAM RLS or DFSMStvs processing. If the data set is opened
for input in non-RLS mode, a VSAM RLS or DFSMStvs open is allowed.
As
in SHAREOPTIONS 3, each user is responsible for maintaining both read
and write integrity for the data the program accesses.
- crosssystem
- Specifies the amount
of sharing allowed among systems. Job steps of two or more operating
systems can gain access to the same VSAM data set regardless of the
disposition indicated in each step's DD statement for the data set.
However, if you are using GRS across systems or JES3, the data set
might not be shared depending on the disposition of the system.
To
get exclusive control of the data set's volume, a task in one system
issues the RESERVE macro. The level of cross-system sharing allowed
by VSAM applies only in a multiple operating system environment.
The
cross-system sharing options are ignored by RLS or DFSMStvs processing.
The values are:
-
- 1
- Reserved
- 2
- Reserved
- 3
- Specifies that the data set can be fully shared. With this option,
each user is responsible for maintaining both read and write integrity
for the data that user's program accesses. User programs that ignore
write integrity guidelines can cause VSAM program checks, uncorrectable
data set errors, and other unpredictable results. This option requires
each user to be responsible for maintenance. The RESERVE and DEQ macros
are required with this option to maintain data set integrity. (For
information on using RESERVE and DEQ, see z/OS MVS Programming: Authorized Assembler Services Reference ALE-DYN and z/OS MVS Programming: Authorized Assembler Services Reference LLA-SDU.)
- 4
- Indicates that the data set can be fully shared. For each request,
VSAM refreshes the buffers used for direct processing. This option
requires that you use the RESERVE and DEQ macros to maintain data
integrity while sharing the data set. Improper use of the RESERVE
macro can cause problems similar to those described under SHAREOPTIONS
3. (For information on using RESERVE and DEQ, see z/OS MVS Programming: Authorized Assembler Services Reference ALE-DYN and z/OS MVS Programming: Authorized Assembler Services Reference LLA-SDU.)
Output processing is limited to update, or add processing, or both
that does not change either the high-used RBA or the RBA of the high
key data control interval if DISP=SHR is specified.
To ensure data integrity in a shared environment,
VSAM provides users of SHAREOPTIONS 4 (cross-region and cross-system)
with the following assistance: - Each PUT request immediately writes the appropriate buffer to
the VSAM cluster's DASD space. That is, the buffer in the user's address
space that contains the new or updated data record, and the buffers
that contain new or updated index records when the user's data is
key-sequenced.
- Each GET request refreshes all the user's input buffers. The contents
of each data and index buffer being used by the user's program is
retrieved from the VSAM cluster's DASD.
Abbreviation: SHR
- SPANNED|NONSPANNED
- Specifies
whether a data record is allowed to cross control interval boundaries.
If SPANNED or NONSPANNED is specified in the SMS data class, the
value defined is used as the data set definition, unless it has been
previously defined with an explicitly specified or modeled DEFINE
attribute.
This parameter cannot be used when defining a linear
data set cluster. - SPANNED
- Specifies
that, if the maximum length of a data record (as specified with RECORDSIZE)
is larger than a control interval, the record is contained on more
than one control interval. This allows VSAM to select a control interval
size that is optimum for the DASD.
When a data record that is
larger than a control interval is put into a cluster that allows spanned
records, the first part of the record completely fills a control interval.
Subsequent control intervals are filled until the record is written
into the cluster. Unused space in the record's last control interval
is not available to contain other data records.
Using
this parameter for a Variable-Length or a Fixed-Length Relative Record
Data Set causes an error.
Abbreviation: SPND
- NONSPANNED
- Indicates
that the record must be contained in one control interval. VSAM selects
a control interval size that accommodates your largest record.
Abbreviation: NSPND
- SPEED|RECOVERY
- Specifies whether the data component's control areas are to be
preformatted during loading.
This parameter is only considered
during the actual loading (creation) of a data set. Creation occurs
when the data set is opened and the high-used RBA is equal to zero.
After normal CLOSE processing at the completion of the load operation,
the physical structure of the data set and the content of the data
set extents are exactly the same, regardless of which option is used.
Any processing of the data set after the successful load operation
is the same, and the specification of this parameter is not considered.
If
you use RECOVERY, the initial load takes longer because the control
areas are first written with either empty or software end-of-file
control intervals. These preformatted control intervals are then updated,
using update writes with the data records. When SPEED is used, the
initial load is faster. - SPEED
- Does
not preformat the data component's space.
If the initial load
is unsuccessful, you must load the data set again from the beginning
because VSAM cannot determine the location of your last correctly
written record. VSAM cannot find a valid end-of-file indicator when
it searches your data records.
- RECOVERY
- Does
preformat the data component's space prior to writing the data records.
If the initial load is unsuccessful, VSAM can determine the location
of the last record written during the load process.
Abbreviation: RCVY
- STORAGECLASS(class)
- For
SMS-managed data sets: Gives the name, 1-to-8 characters of the
storage class.
Your storage administrator defines the names of
the storage classes you can use. A storage class is assigned either
when you use STORAGECLASS, or an ACS routine selects a storage class
for the new data set. The storage class provides the storage attributes
that are specified on the UNIT and VOLUME operand for non-SMS managed
data sets. Use the storage class to select the storage service level
to be used by SMS for storage of the data set. If SMS is inactive
and STORAGECLASS is used, the DEFINE will be unsuccessful.
STORAGECLASS
cannot be selected as a subparameter of DATA or INDEX.
Abbreviation: STORCLAS
- TO(date)|FOR(days)
- Specifies the retention period for the cluster being defined. If neither TO nor
FOR is used, the cluster can be deleted at any time. The MANAGEMENTCLASS
maximum retention period, if selected, limits the retention period
specified by this parameter.
For non-SMS-managed data sets, the
correct retention period is reflected in the catalog entry. The VTOC
entry cannot contain the correct retention period. Enter a LISTCAT
command for the correct expiration date.
For SMS-managed data
sets, the expiration date in the catalog is updated and the expiration
date in the format-1 DSCB is changed. If the expiration date in the
catalog does not agree with the expiration date in the VTOC, the VTOC
entry overrides the catalog entry. - TO(date)
- Specifies
the earliest date that a command without the PURGE parameter can delete
an entry. Specify the expiration date in the form yyyyddd,
where yyyy is a four-digit year (to a maximum
of 2155) and ddd is the three-digit day
of the year from 001 through 365 (for non-leap years) or 366 (for
leap years).
The following four values are "never-expire" dates:
99365, 99366, 1999365, and 1999366. Specifying a "never-expire"
date means that the PURGE parameter will always be required to delete
an entry. For related information, see the "EXPDT Parameter" section
of z/OS MVS JCL Reference.
Note:
Specifying the current date as the expiration
date will make an entry eligible for deletion.
- FOR(days)
- Specifies
the number of days you want to keep the cluster being defined. The
maximum number is 93000. If the number is 0 through 92999 (except
for 9999), the entry is retained for the number of days indicated.
If the number is either 9999 or 93000, the entry is retained indefinitely.
There is a hardware imposed expiration date of 2155.
- WRITECHECK|NOWRITECHECK
- indicates whether the cluster or component is to be checked by
a machine action called write check when a record is written into
it.
The WRITECHECK setting is ignored when the data set is opened
for VSAM RLS or DFSMStvs access.
- WRITECHECK
- Shows
that a record is written and then read, without data transfer, to
test for the data check condition.
Abbreviation: WCK
- NOWRITECHECK
- Use
when the cluster or component is not to be checked by
a write check.
Abbreviation: NWCK
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