Dataset Define Cluster dialog box
You use this dialog to issue an IDCAMS DEFINE CLUSTER command to define attributes for a cluster as a whole and for the components of a cluster.
The Options tab of this dialog box provides the following options in three tabbed subsections: the Cluster tab, the Data tab, and the Index tab. These tabs correspond to the cluster that you define and its data and index components. You specify many of the same attributes for each of the three entities (cluster, and its data and index components). The values that you specify are unique to each entity.
To learn about the standard capabilities of a dialog box, see Standard tabs in the dialog boxes of the Storage Toolkit. The topic includes a link to the Reference guides for commands that are used in the Storage Toolkit.
Option | Description |
---|---|
Fully Qualified Name | Type the fully-qualified entryname for the cluster. This name is not propagated to the DATA and INDEX components of the cluster. For SMS and non-SMS-managed clusters, the component names must resolve to the same catalog as the cluster name of the data set. You can define a separate entryname for the cluster, its data component, and its index component. If no name is specified for the data and index component, a name is generated. When the cluster, data component, and index component are individually named, each can be addressed. |
Fully Qualified Model | Type the fully-qualified name of the cluster that you want to use as a model. |
Space Units | Select the unit of space that you want to allocate in the volume. Options include cylinders, kilobytes, megabytes, records, or tracks. Then specify a corresponding value for the unit that you selected. The Primary value that you specify allocates the initial amount of space to the cluster. The Secondary value that you specify allocates an amount of space for each time the cluster extends. |
Volser(s) | Specifies the volumes on which a cluster is
to have space. The maximum number of VOLSERs is 59. Choose one of
the following values in the list:
|
Control interval size | The size of the control interval for the cluster. |
Buffer space | Specifies the minimum space for buffers. If you do not specify a value, 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. |
Data class | Identifies the name (1-to-8 characters) of the data class for the data set. This metric provides the allocation attributes for new data sets. |
Account | Specify up to 32-bytes of accounting information and user data for the data set. The information is supported for only SMS-managed VSAM and non-VSAM data sets. The information is used only for the data set level (not member level) of PDSE/PDS. |
Management class | For SMS-managed data sets, you can type the name of the management class for a new data set. |
Owner | Type the name of the owner of the cluster. |
Storage class | For SMS-managed data sets, you can type the name of the storage class. Your storage administrator defines the range of names that you can use for storage classes. |
Catalog | Type the name of the catalog in which you want to define the entry. |
Erase | Specifies that the cluster is overwritten with binary zeros when its entry in the catalog is deleted. |
Recatalog | Select this option to cause the catalog entries for the cluster components to be re-created from information in the VVDS, if valid VVDS entries are found on the primary VVDS volume. |
Reuse | Select this option to enable the cluster to be opened repeatedly as a reusable cluster. |
Spanned | Select this option to enable a data record to cross the boundaries of a control interval. 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 option allows VSAM to select a control interval size that is optimal for the DASD. You cannot use this option in the definition of a linear data set cluster. |
Speed | Select this option to prevent preformatting of the control areas of the data component during loading (creation) of a data set. |
Data organization type | By default, the data organization type is set to Indexed. Use this option to specify the type of data organization for the cluster: Indexed, Linear, Non-indexed, or Numbered. |
Option | Description |
---|---|
Fully Qualified Name | Type the fully-qualified name of the data component. |
Fully Qualified Model | Type the fully-qualified name of the data component that you want to use as a model. |
Space Units | Select the unit of space that you want to allocate in the volume. Options include cylinders, kilobytes, megabytes, records, or tracks. Then specify a corresponding value for the unit that you selected. The Primary value that you specify allocates the initial amount of space to the data component. The Secondary value that you specify allocates an amount of space for each time the data component extends. |
Volser(s) | Specifies the volumes on which a component is
to have space. The maximum number of VOLSERs is 59. Choose one of
the following values in the list:
|
Control interval size | The size of the control interval for the component. |
Buffer space | Specifies the minimum space for buffers. If you do not specify a value, 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 |
Record Size | Specifies the average and maximum lengths, in
bytes, of the records in the data component. The minimum record size
is 1 byte.
|
Free Space | Specifies the percentage of each control interval
(CI) and control area (CA) to be set aside as free space when the
cluster is initially loaded or when a mass insert is done. The value
of CI% is the percentage of space to be preserved for adding new records
and updating existing records with an increase in the length of the
record. Because 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. |
Share Options | These settings determine how a component or
cluster can be shared among users. To ensure integrity, you should
be sure that share options specified at the DATA and INDEX levels
are the same.
|
Keys | In this area, you can specify information about
the prime key field of a key-sequence data records of a data set.
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.
|
Erase | Select this option to cause components to be overwritten with binary zeros when their entries in the catalog are deleted. |
Reuse | Select this option to enable the component to be opened repeatedly as a reusable cluster. |
Spanned | Select this option to enable a data record to cross the boundaries of a control interval. If the maximum length of a data record (as specified with Record Size) is larger than a control interval, the record is contained on more than one control interval. This option allows VSAM to select a control interval size that is optimum for the DASD. |
Speed | Select this option to prevent preformatting of the control areas of the data component during loading (creation) of a data set. |
Option | Description |
---|---|
Fully Qualified Name | Type the fully-qualified name of the index component. |
Fully Qualified Model | Type the fully-qualified name of the index component that you want to use as a model. |
Space Units | Select the unit of space that you want to allocate in the volume. Options include cylinders, kilobytes, megabytes, records, or tracks. Then specify a corresponding value for the unit that you selected. The Primary value that you specify allocates the initial amount of space to the data component. The Secondary value that you specify allocates an amount of space for each time the index component extends. |
Volser(s) | Specifies the volumes on which a component is
to have space. The maximum number of VOLSERs is 59. Choose one of
the following values in the list:
|
Control interval size | The size of the control interval for the component. |
Share Options | These settings determine how a component or
cluster can be shared among users. To ensure integrity, you should
be sure that share options specified at the DATA and INDEX levels
are the same.
|
Reuse | Select this option to enable the component to be opened repeatedly as a reusable cluster. |