Maintaining Objects of Type Dataspace

This document covers the following topics:

For general information on how to manage objects (for example, how to add or copy an object), see the Object Description documentation.

Adding a Dataspace

When you add a dataspace, you first have to specify the dataspace type in the Type dialog box.

Type

When you choose the OK button, a dataspace type-specific window appears. The dataspace type is indicated in the title bar.

Defining Basic Attributes of Dataspace - DB2 Mainframe

The following window applies to DB2 mainframe dataspaces.

DB2 tablespace

Parameters
Tablespace name Name of the table space in DB2.
Type
Table space type.
S Segmented.
P Partitioned.
R Range partitioned.
G Partition by growth.
' ' Simple. This is the default setting.
Nr of partitions

Number of partitions used by the table space (corresponding to the NUMPARTS parameter, max. 4096) for table space type P or R. If 0 is specified, the table space is not partitioned.

Maximum number of partitions used by the table space (corresponding to the MAXPARTITIONS parameter, max. 4096) for table space type G.

Partitions can be defined

Partitions can be defined explicitly or with default values (see Using/free clause below) if table space type is either P or R. Partition definitions are used when generating table spaces from Predict dataspace objects.

Large
Identifies a table space as large.
Y Yes.
N No.
Buffer pool Name of the buffer pool to be associated with the table space.
Partition size Only valid for partitioned tablespaces.
Locksize
Locking level for the table space. Valid values:
A any level locking
P page level locking
R row level locking
S table space level locking.
T table level locking (only valid for segmented DS)
Pages per segment

How many pages are to be assigned to each segment (parameter SEGSIZE) for table space type S, G or R.

Pages per segment must be zero for table space type ' ' (Simple) or P.

Logged
blank Not specified. This is the default setting.
Y Yes.
N No.
Close option
Y The data sets which support the table space are closed when nobody is using the table space.
Lockmax
The maximum number of pages or row locks an application can hold simultaneously in the table space. Valid values:
blank  
SYSTEM  
0 - 2,147,483,647.  
If parameter Locksize is set to S or T, Lockmax must be set to 0.
Lockpart
Partition locking. Valid values:
blank not specified
Y Yes
N No
Maxrows The maximum number of rows.
CCSID
Encoding scheme. Valid values:
blank not specified
A ASCII
E EBCDIC
Member cluster
Specifies that data inserted by the INSERT statement is not clustered by the implicit clustering index (the first index) or the explicit clustering index. Instead, DB2 chooses where to locate the data in the table space based on available space. Valid values:
blank not specified
Y Yes
N No

Definition of Using/Free Clause

The values specified in the Definition of using/free clause tab are used as default values.

Definition of using/free clause

Parameters
VSAM catalog name Name of the VSAM catalog containing an entry for the data sets of the table space. Must not be specified if the parameter Storagespace is specified.
Storagespace Name of the storagespace for the table space documented with the Predict Dataspace object. Must not be specified if the parameter VSAM catalog is specified.
Primary attributes
Free pages How often pages are to be left free when loading or reorganizing table spaces or partitions. Max. value is 255. Default is 0, leaving no free pages.
Percentage free Percentage of each page to be left free. Equivalent in DB2 is the PCTFREE option.
for update

Percentage of each page that is reserved to be used only by future update operations. Equivalent in DB2 is the PCTFREE FOR UPDATE option.

When you specify -1, DB2 uses real-time statistics to automatically calculate how much free space to reserve for updates. This is the default.

Compress option Specifies whether data compression applies to the rows of the tablespace.
GBPCACHE
Only relevant in a data sharing environment. Specifies what pages of the table space or partition are written to the group buffer pool. Leave this field blank or enter:
C Changed. Only pages that have been changed are written to the group buffer pool.
A All pages are written.
N No pages are written to the group buffer pool.
TRACKMOD
Specifies whether DB2 tracks changed pages in the space map pages.
Y Changed pages are tracked in the space map pages.
N Changed pages are not tracked.
Additional for storagespace
Primary allocation Primary space allocation for DB2 defined data sets.
Secondary allocation Secondary space allocation for DB2 defined data sets.
Erase option
Determines if DB2 defined data sets are to be erased when the table space is dropped:
N Do not erase data sets (default).
Y Erase data sets.

Defining Partitions

Each individual partition can be defined in the Definition of partitioned dataspace tab. The maximum number of partitions is 4096.

To define a new partition, use the New button. When you have defined more than one partition, a scroll bar is available. To go to a specific partition, use the scroll bar. To delete the currently displayed partition, choose the Delete button.

Definition of partitioned dataspaces

Parameters
See previous table above for a description of the parameters.

Defining Basic Attributes of Dataspace - SQL/DS

The following window applies to SQL/DS dataspaces.

SQL/DS dataspace

Parameters
Tablespace name Identifier of the table space and name of the DBspace in SQL/DS.
Private dataspace
Y SQL/DS DBspace is private.
N Dataspace is public.
Size for header Number of 4096-byte logical pages reserved for header.
Size for dataspace Size reserved for the dataspace.
Percentage for indices Percentage of the reserved space that can be used for indexes.
Percentage free Percentage of reserved space to be kept free.
Locksize
Locking level for the dataspace. Valid values:
A Any level locking
P page
S dbspace
R row
T table
Storage pool number Storage pool number. This parameter tells SQL/DS to acquire the dbspace from a specified storage pool.

Defining Basic Attributes of Dataspace - DB2 Open Systems

The following window applies to DB2 open systems dataspaces.

DB2 OS tablespace

Parameters
Tablespace name Name of the tablespace in DB2.
Storagespace Name of the storagespace for the tablespace documented with the Predict dataspace object.
Data type
Valid data types:
R Regular
L Large
U User temporary
S System temporary
blank not specified
Page size Defines the size of pages used for the tablespace. Valid values: 4K, 8K, 16K, 32K, 4096, 8192, 16384, 32768 or not specified.
Space type
Specifies how the tablespace is to be managed:
S System managed
D Database managed
Extent size Specifies the number of PAGESIZE pages that will be written to a container before skipping to the next container. Valid values are 0 or integer or integer with unit K, M or G.
Prefetch size Specifies the number of PAGESIZE pages that will be written to a container before skipping to the next container. Valid values are 0 or integer or integer with unit K, M or G.
Buffer pool Name of the buffer pool to be associated with the tablespace.
Overhead Specifies the I/O controller overhead and disk seek and latency time (in milliseconds).
Transfer rate Specifies the time to read one page into memory (in milliseconds).
Dropped table
Specifies if dropped tables in the tablespace may be recovered. Valid values:
Y Yes
N No
blank Not specified

Container Definitions

The following window applies when defining containers.

DB2 OS tablespace container definitions

Parameters
Container number (1, 2, etc.) Specifies the container for a tablespace. Choose New to enter a new container. Use the scrollbar to select an existing container (only applicable if more than one container exists).
Partition numbers Specifies the partition numbers on which the container is created in a partitioned database.