7.9.3 Control statement (alter rdarea statement)

This section explains the operands of the alter rdarea statement. In the following table, each number corresponds to the number assigned to each operand.

No.Operand
1alter rdarea RDAREA-name
2open attribute {INITIAL|DEFER|SCHEDULE}]
3[extension {use extension-segments-count segments|nouse}]
[Figure];
Organization of this subsection
(1) RDAREA-name <identifier> ((1-30))
(2) open attribute {INITIAL|DEFER|SCHEDULE}
(3) extension {use extension-segments-count segments|nouse}

(1) RDAREA-name[Figure] <identifier> ((1-30))

Specifies the name of the RDAREA whose open timing is to be changed. ALL cannot be specified for RDAREA-name. If the RDAREA name is enclosed in double quotation marks ("), it is handled as case sensitive; otherwise, it is handled as all uppercase letters. An RDAREA name must be enclosed in double quotation marks if it includes a blank.

(2) open attribute {INITIAL|DEFER|SCHEDULE}

Specifies the RDAREA open timing.

Criteria
Normally, specify INITIAL unless some special operation mode is used.
To reduce the HiRDB startup time when there are many RDAREAs, specify DEFER.
Rules
  1. This operand takes effect only when Y is specified in the pd_rdarea_open_attribute_use operand in the system common definitions.
  2. This operand is applicable to user RDAREAs, user LOB RDAREAs, and list RDAREAs. This operand is ignored if specified for any other type of RDAREA (the RDAREA open timing for all other RDAREA types is INITIAL).
  3. When this operand is omitted, the system assumes the value existing before the RDAREA attributes were modified.
  4. The value of this operand takes effect at the next startup, regardless of the HiRDB startup mode.
  5. If the HiRDB file system area assigned to the corresponding RDAREA is shared by other RDAREAs, all such RDAREAs must have the same open timing. Otherwise, an expected result may not be obtained from the RDAREAs sharing the HiRDB file system area.
INITIAL
The RDAREA's HiRDB file system area is to be opened at the time of system startup and the RDAREA information is to be made resident in memory; thus, high-speed operation is available from the first SQL.
Rules
  1. The RDAREA's initial status at system startup is open and remains unchanged until an operation command is executed, unless it is placed in error shutdown status due to an error.
  2. The INITIAL open attribute does not permit access to a closed RDAREA.
DEFER
The RDAREA's HiRDB file system area is not to be opened at the time of system startup; rather, it is to be opened and its RDAREA information is to be made resident in memory the first time an RDAREA in the HiRDB file system area is accessed. Thus, high-speed operation is available beginning with the second access to the HiRDB file system area.
Rules
  1. The RDAREA's initial status at system startup is closed and changes to open the first time an RDAREA in its HiRDB file system area is accessed. The HiRDB file system area's RDAREAs remain in open status thereafter until an operation command is executed, unless they are placed in error shutdown status due to an error.
  2. The DEFER open attribute permits access to a closed RDAREA.
SCHEDULE
The RDAREA's HiRDB file system area is not to be opened at the time of system startup; rather, it is to be opened and the RDAREA information is to be made resident in memory the first time an RDAREA in the HiRDB file system area is accessed from within a transaction. When this attribute is used, transaction workload increases because a HiRDB file system area opened by a transaction is closed when the transaction terminates, and open processing must be performed on the HiRDB file system area the first time each transaction accesses one of its RDAREAs.
Rules
  1. The RDAREA's initial status at system startup is closed and changes to open when the RDAREA is first accessed by a transaction. When the transaction is terminated, all the RDAREAs opened by it are closed. You can use the pdopen command to keep RDAREAs in open status until they are placed in shutdown close status. You can also use other operation commands to change the RDAREA status. However, if an error is detected, RDAREAs are placed in error shutdown status.
  2. The SCHEDULE open attribute permits access to a closed RDAREA.

(3) extension {use extension-segments-count segments|nouse}

Specifies whether or not to apply automatic extension to the RDAREA for which attributes are being modified. When this operand is omitted, the value existing before attribute modification takes effect.

Automatic extension of RDAREA is a facility that extends automatically an RDAREA in the event of a shortage of RDAREA space if there is enough space in the HiRDB file system area. If you use this facility for an RDAREA and a shortage of unused segments occurs, the system allocates new unused segments to the RDAREA. These new unused segments are added at the end of the HiRDB file constituting the RDAREA.

Prerequisites
  1. You need to specify the -e option (specifying the number of extensions) for the HiRDB file system area containing the RDAREA.
  2. There must be enough space in the HiRDB file system area that contains the last HiRDB file constituting the RDAREA.
use extension-segments-count segments
Specifies that automatic extension of RDAREA is to be applied.
The automatic extension of RDAREA is applicable to data dictionary RDAREAs, data dictionary LOB RDAREAs, user RDAREAs, and user LOB RDAREAs. For any other type of RDAREA, the system assumes nouse, even if use is specified.
For an RDAREA other than a LOB RDAREA, automatic extension occurs when there are no more used free segments or used segments. For a LOB RDAREA, automatic extension occurs when there are no more unused segments.
extension-segments-count[Figure] <unsigned integer> ((1-64000))
Specifies the number of extension segments.
The maximum number of HiRDB file extensions is 24. If this value is exceeded, an error occurs. The maximum number of extensions per HiRDB file system area is determined by the value specified when the HiRDB file system area is created. Therefore, you need to define the maximum number of extensions taking into account the number of files in the HiRDB file system area and the frequency of extension.
nouse
Specifies that automatic extension of RDAREA is not to be applied.
Notes
  1. If allocation of unused segments fails due to a shortage of space in the HiRDB file system area, either extend or re-initialize the RDAREA or use the database reorganization utility to reorganize the table.
  2. If the number of extensions exceeds the maximum value, integrate the extensions in the HiRDB file system area containing the RDAREA or add an HiRDB file in another HiRDB file system area to the RDAREA.
    To integrate extensions, make a backup copy with pdfbkup, initialize the HiRDB file system area with pdfmkfs, then restore the HiRDB file system area from its backup copy using pdfrstr.
  3. The last file is locked from the beginning to the end of the automatic extension process.