7.9.3 Control statement (alter rdarea statement)
(1) RDAREA-name~<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 space.
The attributes of in-memory RDAREAs cannot be changed. To do so, first release the RDAREA from memory, then change the RDAREA's attributes.
(2) rename rdarea to new-RDAREA-name
~<identifier>((1-30))
Specifies a new name for the RDAREA.
ALL cannot be specified for a new RDAREA name. If the RDAREA name is enclosed in double quotation marks ("), it is handled as case sensitive; otherwise, it is handled as all upper-case letters. If the new RDAREA name contains a space, it must be enclosed in double quotation marks.
For details about how to rename an RDAREA, see the HiRDB Version 9 System Operation Guide.
- Rules
- This operand is applicable to user RDAREAs, user LOB RDAREAs, list RDAREAs, data dictionary RDAREAs, data directory RDAREAs, data dictionary LOB RDAREAs, registry RDAREAs, and registry LOB RDAREAs.
- Notes
- An error results if there is already an RDAREA with the specified new RDAREA name.
- For details about handling warning messages that might be displayed when an RDAREA is renamed, see the HiRDB Version 9 System Operation Guide.
(3) 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
- This operand takes effect only when Y is specified in the pd_rdarea_open_attribute_use operand in the system common definitions.
- 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).
- When this operand is omitted, the system assumes the value existing before the RDAREA attributes were modified.
- The value of this operand takes effect at the next startup, regardless of the HiRDB startup mode.
- 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
- 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.
- 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
- 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.
- 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
- 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.
- The SCHEDULE open attribute permits access to a closed RDAREA.
(4) 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.
For details about RDAREA automatic extension, see the HiRDB Version 9 System Operation Guide.
- Prerequisites
- You must specify the -e or -a option for the HiRDB file system area containing 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.
- Automatic extension occurs when the number of free segments in an RDAREA reaches the automatic extension timing. You specify the timing value in the pd_rdarea_extension_timing operand.
- extension-segments-count ~<unsigned integer> ((1-64000))
- Specifies the number of extension segments.
- For a HiRDB file system area for which pdfmkfs -e is specified
The maximum number of HiRDB file extensions is 24. If this value is exceeded, an error occurs. An error occurs if a shortage of space occurs in the HiRDB file system area or the required area exceeds the maximum size for a HiRDB file.
The maximum number of extensions per HiRDB file system area is determined by a value specified when the HiRDB file system area was created. Therefore, when you define the maximum number of extensions, you must take into account the number of files in the HiRDB file system area and the frequency of extension.
- For a HiRDB file system area for which pdfmkfs -a is specified
An error occurs if there is not enough space on the disk containing the HiRDB file to allocate the required HiRDB file system area or the required area exceeds the maximum size for a HiRDB file.
- nouse
- Specifies that automatic extension of RDAREA is not to be applied.
- Notes
- New unused segments are added to the last HiRDB file constituting the RDAREA.
- 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.
- If the number of extensions exceeds the maximum value, integrate the extensions in the HiRDB file system area containing the RDAREA or add a 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, and then restore the HiRDB file system area from its backup copy using pdfrstr.
- The last file is locked from the beginning to the end of the automatic extension process.