11.5 Notes

  1. The maximum number of pdreclaim commands that can be executed concurrently is the same as for the pdrorg command because pdreclaim executes pdrorg internally. Specifically, the maximum number of pdreclaim commands that can be executed concurrently equals the maximum number of pdrorg commands that can be executed concurrently minus the number of pdrorg commands that are currently executing.
  2. pdreclaim cannot process view tables or external tables.
  3. pdreclaim cannot process LOB RDAREAs. This means that pdreclaim cannot process any LOB RDAREA containing an abstract data type or plug-in index.
  4. If a UAP accesses a page in an index that is being released, pdreclaim is placed in wait status until the corresponding process transaction is settled. You can specify a wait time for pdreclaim in the -w option.
  5. To terminate pdreclaim forcibly, use the pdcancel command. Other commands such as the OS's kill command cannot terminate pdreclaim.
  6. When executing pdreclaim with the -j option specified, we recommend that you shut down the applicable RDAREAs with the pdhold command to protect UAPs from being placed in lock-release wait status unnecessarily.
    When the -j option is specified in pdreclaim, the RDAREA storing the specified table and index is placed in the EX lock mode, making the entire RDAREA inaccessible. This lock control functions based on the specification of the -w and -n options, as shown in Table 11-8.

    Table 11-8 Lock control during free segment release processing

    Option valueLock-release wait time per processingIn the event of a lock error
    -w-nLock-release wait timeout errorOther error
    Retry lockingRetries countProcessingProcessing
    Not specified[Figure]Indefinite[Figure][Figure][Figure][Figure]
    SpecifiedNot specifiedTime specified in the -w optionNo0Displays an error message and then cancels processing.Processing
    SpecifiedYesCount specified in the -n optionRetries locking as many times as the value specified in the -n option.
    If all retries result in a timeout, the system displays an error message and then cancels processing.
    Legend:
    [Figure]: Not applicable
    Table 11-9 shows the resources that are locked during free segment release processing.

    Table 11-9 Resources that are locked during free segment release processing

    Resource nameResource numberNodePurposeWhether or not locking is retried
    pdreclaim5006EXSuppression of multiple concurrent executions of pdreclaim on the same resourceThere are no retries because processing is cancelled if pdreclaim is executing.
    RDAREA ID0001EXSuppression of access to an RDAREA that is the subject of free segment release processingLocking is retried when a lock-release wait timeout error occurs and the -n option is specified.
    RRAMB0102SRNo timeout error occurs because this resource is acquired only after the RDAREA has been placed in the EX lock mode. Therefore, there are no retries.
  7. Table 11-10 shows the return codes of pdreclaim.

    Table 11-10 Return codes of pdreclaim

    Return codeDescriptionAction
    0Release of used free pages or segments has been completed.None
    4Processing was cancelled because a timeout occurred while waiting for settlement of a UAP transaction.The table and index status is guaranteed because release of used free pages was cancelled due to a timeout. The table and indexes can be accessed from UAPs as is. To release the remaining used free pages, re-execute pdreclaim.
    8Processing terminated abnormally.The table and index status is guaranteed because release of used free pages was cancelled due to an error. Even after abnormal termination, the table and indexes can be accessed from UAPs. To re-execute pdreclaim, first check the displayed error messages and eliminate the cause of the error.
  8. If the target table contains a user-defined column of an abstract data type, pdreclaim cannot be executed.
  9. To execute pdreclaim on a shared table or shared index, the system places the RDAREAs containing the shared table or shared index in the EX lock mode. If the corresponding RDAREAs contain other tables or indexes, these tables and indexes cannot be referenced or updated. For details about the lock mode used for executing pdreclaim, see Appendix B.2 Lock mode for utilities.
  10. For a HiRDB/Parallel Server, if a transmission message from a back-end server to pdreclaim is delayed for 1 second or more due to traffic on the communication line, the corresponding back-end server's processing result may not be displayed at the standard output. In this case, check the KFPL00714-I message that is output to the message log file or syslogfile to determine the processing result.
  11. Do not execute a definition SQL statement on a table or index that is being processed by pdreclaim. If a definition SQL statement is so executed, pdreclaim terminates abnormally. If pdreclaim is executing in units of schemas, it processes all tables and indexes that belong to the corresponding schema.
  12. If you selected utf-8 as the character encoding in the pdsetup command, you can use a file with a BOM as the control statements file for pdreclaim; however, the BOM is skipped.