PK86944: PERFORMANCE PROBLEM WHEN UNLOADING LARGE TABLE SPACES.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Performance is slow when unloading large tablespaces. Getting
  dynamic allocation failure:
  INZI330E DYNAMIC ALLOCATION FAILED. TEMPLATE=OUTLOB
           RC=4, REASON=0x970c
  INZU366I UTILITY RETURN CODE 8 (REASON CODE 0x12ea001)
  The LDS is allocated and freed for each member = for each
  LOBFILE written in it. When unloading large table spaces, this
  can have a great (negative) impact on the performance of the
  unload.                   PB 10035
  

Local fix

• ADDITIONAL SYMPTOMS:
  1. When unloading LOB data into LOBFILEs stored as members of a
     PDS, using a TEMPLATE, allocation messages are issued for
     each member created in the PDS.
     This APAR changes the allocation process to have a single
     allocation and improves the overall performance.
     PB 10035
  2. UNLOAD LOB TO PDS GENERATES IEB421I I/O ERROR
     PB 10112
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of DB2 High Performance Unload.        *
  ****************************************************************
  * PROBLEM DESCRIPTION: 1. Irrelevant INZU063I UNSUPPORTED      *
  *                      SELECT message is issued when           *
  *                      attempting to unload from a MQT         *
  *                      (Materialized Query Table).             *
  *                      PB 9934                                 *
  *                      2. When unloading two or more LOB       *
  *                      columns into the same PDS file using a  *
  *                      TEMPLATE and LOB FILE REFERENCE         *
  *                      (CLOBF, DBCLOBF, BLOBF data types),     *
  *                      data from the first column is           *
  *                      overriden by data from the second       *
  *                      column. In addition the two LOB FILE    *
  *                      REFERENCE for the two columns point to  *
  *                      the same member.                        *
  *                      This situation should not be accepted.  *
  *                      The correct processing is to write each *
  *                      LOB file reference into a separate PDS  *
  *                      file.                                   *
  *                      This same problem also occurs between   *
  *                      one LOB column and one XML column, or   *
  *                      between two XML columns.                *
  *                      PB 9971                                 *
  *                      3. When unloading LOB data into         *
  *                      LOBFILEs stored as members of a PDS,    *
  *                      using a TEMPLATE, allocation messages   *
  *                      are issued for each member created in   *
  *                      the PDS.                                *
  *                      This APAR changes the allocation        *
  *                      process to have a single allocation     *
  *                      and improves the overall performance.   *
  *                      PB 10035                                *
  ****************************************************************
  * RECOMMENDATION: APPLY the PTF.                               *
  ****************************************************************
  1. Modules oddldb2, inzctrl  and inzctrlz were changed to
  process correctly the MQT.
  2. Module inzctrlh was changed to check that two LOB or XML
  columns are not unloaded in the same PDS file using a TEMPLATE
  and lob file reference.
  3. Module ubbspwlf was changed to use BPAM access method
  instead of Dynamic allocation of members and QSAM.
  

Problem conclusion

• APPLY the PTF.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UK50086

Modules/Macros

•    INZADBSK INZIVPSK INZRSKEL INZSIVP  INZUTILK
  

Fix information

• Fixed component name

  DB2 HI PERF UNL

• Fixed component ID

  5697F4400

Applicable component levels

• R310 PSY UK50086

     UP09/10/05 P F910

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.