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IBM DB2 Analytics Accelerator for z/OS Version 5.1.0 maintenance level PTF-2: Release Notes

Release Notes


Abstract

This document describes enhancements and fixes in IBM DB2 Analytics Accelerator for z/OS Version 5.1.0, maintenance level PTF-2.

Content


Heads up

April 2016: We recommend an upgrade of the accelerator server component to this V5.1.0-PTF2 for customers at product level V5.1.0 GA or older than V5.1.0 PTF-1 (UI35012, which was set PE).

With V5.1.0. GA and V5.1.0. PTF-1, a new way of data organization was introduced. The new organization has the potential to speed up the insertion of small chunks of data, which are typical for incremental updates. In rare situations, with huge table sizes, this new way of organizing data might lead to different query results returned by DB2 for z/OS and the accelerator. You can avoid this problem by switching back to the former way of data organization.

After an installation of V5.1.0 PTF-2, the former method of data organization is re-activated. If the switch back to the former data organization fails, the following message is written to the z/OS system log (SYSLOG) of the LPAR in which the DB2 subsystem or group is located:
DSNX881I - <SSID> W 2004 ... Not all zone map records are consistent with the expected layout
For further information regarding the structure of DSNX881I messages see:

Structure of DSNX881I Messages.

This is a temporary fix. The problem will be finally fixed with an upcoming release of the Netezza Platform Software (NPS). This NPS release will be certified for use with IBM DB2 Analytics Accelerator for z/OS.
Important: To make sure that all inconsistent data is removed from the accelerator, reload the potentially affected tables as decribed here:
How to identify tables that should be reloaded after an installation of V5.1.0 PTF-2

What's new

Please find information about new functions here

Solved problems

  1. Error message CHC0535E in CDC Jeslog
    Affected users
    All users of the incremental update function in IBM DB2 Analytics Accelerator for z/OS Version 4.1.0 PTF-5 and later versions
    Problem description
    The error message is written, but the message has no effect and can be ignored.
    Problem summary
    When reloading an incremental-update-enabled table, the error message CHC0535E is written to the CDC Jeslog.
    Problem conclusion
    The problem has been fixed. The error message is not written anymore during a reload.
  2. Stored Procedures fail with error AQT10003I
    Affected users
    All users of IBM DB2 Analytics Accelerator for z/OS
    Problem description
    Instead of correctly generated external error messages in the MESSAGE output parameter of stored procedures, a default message AQT10003I is generated.
    Problem summary
    If the accelerator detects warnings in addition to an error, an external error message is not generated correctly.
    Problem conclusion
    The problem has been fixed.
  3. DB2 right() function returns wrong results on CHAR columns
    Affected users
    All users of IBM DB2 Analytics Accelerator for z/OS Version 5.1.0 PTF-1
    Problem description
    CHAR columns yield wrong results
    Problem summary
    When a user issues a DB2 query using the DB2 right() function and the query gets accelerated, wrong results might be produced.
    Problem conclusion
    The problem has been fixed.
  4. The INZA.PMML_MODEL stored procedure fails with error AQT10200E when it uses a model in a Netezza EBCDIC database
    Affected users
    All users of IBM DB2 Analytics Accelerator for z/OS Version 5.1.0
    Problem description
    Stored procedure INZA.PMML_MODEL fails with error AQT10200E: The EXECUTE IMMEDIATE operation failed. Error information: 'DSNT408I SQLCODE = -622, ERROR: FOR MIXED DATA IS INVALID BECAUSE THE MIXED DATA INSTALL OPTION IS NO DSNT418I SQLSTATE = 56031 SQLSTATE RETURN CODE DSNT415I SQLERRP = DSNXICB3 SQL PROCEDURE DETECTING ERROR DSNT416I SQLERRD = 120 0 0 -1 0 0 SQL DIAGNOSTIC INFORMATION DSNT416I SQLERRD = X'00000078' X'00000000' X'00000000' X'FFFFFFFF' X'00000000' X'00000000' SQL DIAGNOSTIC INFORMATION '. The unsuccessful operation was initiated by the following statement: 'CREATE TABLE 'ERIK'.'MODELER_RT3Dr7foihRrJbTMxHldv1gb'('MODELNAME' VARCHAR(64) FOR MIXED DATA,'SEQID' INTEGER,'PMML' VARCHAR(8192) FOR MIXED DATA) IN ACCELERATOR SIM10 IN DATABASE DBINZA4 ccsid EBCDIC'
    Problem summary
    If MIXED=NO is set for a DB2 subsystem, INZA.PMML_MODEL fails with error AQT10200E when it is run on a model in a Netezza EBCDIC database.
    Problem conclusion
    The problem has been fixed.
  5. Accelerator goes offline unexpectedly
    Affected users
    All users of IBM DB2 Analytics Accelerator for z/OS
    Problem description
    An unexpected outage occurs.
    Problem summary
    If the workload is very high and consists not just of LOAD and QUERY tasks, but also of many other tasks, the accelerator can run out of files handles. The accelerator detects this problem automatically and restarts the server process to resolve the situation.
    Problem conclusion
    The problem has been fixed.
  6. Error message AQT20021I when loading a table
    Affected users
    All users of the incremental update function in IBM DB2 Analytics Accelerator for z/OS Version 4.1.0 PTF-5 and later versions
    Problem description
    You receive an AQT20021I error message in the following situation: 1. A table exists on more than one accelerator. The original DB2 table contains columns with data types that are not supported by IBM DB2 Analytics Accelerator. 2. Incremental updates for this table have been configured successfully on at least one accelerator. 3. You have enabled incremental updates for the same table on an additional accelerator. The initial load of this table is outstanding. You receive the error before the initial load of the table. The problem occurs only if the original DB2 table has columns with unsupported data types.
    Problem summary
    Error AQT20021I is returned before the initial load of a table, in the following situation:
    • The table has been enabled for incremental updates
    • The table exists on multiple accelerators.
    • Incremental updates have already been applied to this table on at at least one accelerator,
    • The table is related to a DB2 base table that contains unsupported column data types.
    Problem conclusion
    The problem has been fixed.
  7. Call-home requests with attachments greater than 38 MB will not be opened
    Affected users
    All users of the call-home function in IBM DB2 Analytics Accelerator for z/OS Version 5.1.0
    Problem description
    All events that are supposed to trigger a call-home request will not do so if the attachment size exceeds 38 MB. DSNX881I messages wrongly state that a call-home request will be created automatically, but the fact is that you must open service requests manually for these events.
    Problem summary
    Whenever a call-home event is triggered, log files are collected and sent to IBM along with a general problem description. If these log files exceed 38MB, the call-home request will not be sent at all.
    Problem conclusion
    The problem has been fixed.
  8. Package AQTDBC10 is not bound by the product installer for DB2 11 in Conversion Mode
    Affected users
    All users of IBM DB2 Analytics Accelerator for z/OS Version 5.1.0
    Problem description
    The output of the AQTTRIN installer requires a higher version of DB2 to bind the package AQTDBC10 and does not carry out a BIND operation for this package.
    Problem summary
    If you run the AQTTRIN installer for a DB2 11 for z/OS subsystem in Conversion Mode (CM), the AQTDBC10 package is not bound.
    Problem conclusion
    The problem has been fixed.
  9. Install program AQTTRIN in job AQTTIJSP terminates with condition code 2000
    Affected users
    All users of IBM DB2 Analytics Accelerator for z/OS Version 5.1.0
    Problem description
    The job output shows condition code 2000 for the AQTTRIN installation program.
    Problem summary
    If tracing has been activated for the AQTTRIN step or member of the AQTTIJSP installation job by uncommenting the AQTTRACE DD statement in the JCL, the installation program might end with condition code 2000 although the previous package bind job succeeded. If you restart the job, the program terminates after the next bind operation with the same symptom. This process is repeated until all packages have been bound successfully and the program terminates normally.
    Problem conclusion
    The problem has been fixed.
  10. Values of AQTENV environment variables missing if SCCSID 1026 is used
    Affected users
    All users of IBM DB2 Analytics Accelerator for z/OS Version 5.1.0
    Problem description
    Settings of AQTENV environment variables cannot be retrieved if the RUNOPTS ENVAR clause in a CREATE PROCEDURE statement contains double quotes and if the SCCSID is 1026. All environment variables show empty values in this case.
    Problem summary
    If the SCCSID is 1026, the RUNOPTS ENVAR('_CEE_ENVFILE_S=DD:AQTENV') clause for the definition of stored procedures is not processed correctly by the z/OS Language Environment. As a consequence, the AQTENV data set, which contains the settings of the environment variables, is not read, and hence the values remain unknown to the procedures.
    Problem conclusion
    The problem has been fixed. The installer for stored procedures (AQTTIJSP) ignores quotes in RUNOPTS ENVAR statements to avoid this problem. If the stored procedures were installed before, you must use the REINSTALL option in AQTTIJSP.
  11. An accelerator-only table disappears from accelerator
    Affected users
    Users of IBM DB2 Analytics Accelerator Studio Version 5.1.0 who maintain accelerator-only tables on multiple accelerators paired with the same DB2 subsystem
    Problem description
    When you submit a DROP TABLE statement to remove an accelerator-only table while the accelerator is stopped, the meta-information for that table is removed from DB2, but the table itself remains because the accelerator is unreachable. The statement will be successful, but the following warning is shown: "IWAQ0003W SQL warnings were found... THE DROP STATEMENT FOR OBJECT <schema>.<table> WAS SUCCESSFUL ON THE DB2 SERVER. THE OBJECT MAY NOT HAVE BEEN SUCCESSFULLY PROCESSED ON THE ACCELERATOR SERVER FOR REASON 2. SQLCODE=4748, SQLSTATE=0169B”. This is a hint that information has gone out-of-sync. Suppose that after this message, you create an accelerator-only table, with the same schema and table name as the incompletely removed table, on another accelerator which is paired with the same DB2 subsystem. Suppose further that you remove the first accelerator (the one with incompletely removed accelerator-only table) after that. The unwanted side-effect will be that the newly added accelerator-only table on the second accelerator will also be removed (because it has the same schema and table name).
    Problem summary
    Removing an accelerator containing out of sync accelerator-only tables from a given DB2 for z/OS subsystem might accidentally drop accelerator-only tables with identical schema and table names on another accelerator, paired with the same DB2 for z/OS subsystem.
    Problem conclusion
    The problem has been fixed in IBM DB2 Analytics Accelerator Studio Refresh-Pack 5.1.0.2-Information Management-IDAA Studio-Multiplatform-20160318-1327 and is available on Fix Central.
  12. DEFAULT trace profile does not include installation problems
    Affected users
    All users of IBM DB2 Analytics Accelerator for z/OS
    Problem description
    If the installation fails, customers are often asked to reproduce the problem because the DEFAULT trace profile did not enable the logging of installation errors.
    Problem summary
    The problem occurs when the product installation fails.
    Problem conclusion
    The problem has been fixed. The DEFAULT trace profile now includes installation errors.

Migration recommendations and considerations

For recommendations and considerations concerning migration to IBM DB2 Analytics Accelerator for z/OS Version 5.1.0 read here.

Known issues

  1. IBM Netezza Analytics
    For known issues with the IBM Netezza Analytics stored procedure package in IBM DB2 Analytics Accelerator for z/OS Version 5.1.0, see:

    Known issues with IBM Netezza Analytics for System z for IBM DB2 Analytics Accelerator for z/OS Version 5.1.0

  2. Encryption of Data in Motion
    For known issues with the network traffic encryption feature (encryption of data in motion) in IBM DB2 Analytics Accelerator for z/OS Version 5.1.0, see:

    Known Issues with Encryption of Data in Motion in IBM DB2 Analytics Accelerator for z/OS Version 5.1.0

  3. Transfer of software update packages from IBM DB2 Analytics Accelerator Studio not possible
    Summary
    IBM Analytics Accelerator Studio does not allow users to transfer packages. A message hints at the fact that a newer version is already installed on the server. If the locale in the IBM Analytics Accelerator Data Studio is set to a value different from English or German, the transfer of software update packages might be blocked in rare cases.
    Solution or workaround
    The problem has been fixed with the stored procedures of version 5.1.0 PTF-1. If you run the software transfer with a previous version of the stored procedures, use the following workaround:
    1. Use US English as the locale for IBM DB2 Analytics Accelerator Studio.
    2. On a Windows system, add '-nl en_US' (without the quotes) to the start command that you find in the properties of the shortcut that launches the application ("Target" field on "Shortcut" tab).

      On a Linux system, open the eclipse.ini file and add the following line:

      -Duser.language=en -Duser.country=US

    3. Save and close the file. Then start the application.
  4. If the system utilization is very high, the accelerator might restart automatically to recover from the overload situation
    Summary
    The accelerator goes online again after the recovery. Processes that were ended prematurely by the restart, such as load jobs or queries, must be restarted.
    Solution or workaround
    1. Check the system utilization.
    2. Adjust the system utilization as needed.
    3. Retry failed operations and continue.
  5. Load operations stall if the system utilization is very high
    Summary
    Occasionally, load jobs might end abnormally if the system utilization is very high.
    Solution or workaround
    Cancel and restart the load operation.
  6. The execution of an INSERT INTO ... SELECT ... FROM statement in an in-database transformation job might fail
    Summary
    In rare situations, INSERT INTO ... SELECT ... FROM statements in in-database transformation jobs can fail if the system utilization is very high and many processes are run in parallel.
    Solution or workaround
    This is an indication that the system limits were reached. Check the system utilization and adjust it to the capacity of the system.
  7. Incremental update processing might stop and restart if the system utilization is very high (many parallel load and query operations). This is indicated by according console messages
    Summary
    If the system utilization is very high, with many processes running in parallel, the processing of incremental updates might stop. Processing resumes after some time and stalled operations are recovered automatically. If "continuous incremental updates" are enabled, tables that are being loaded at the time of the interruption go into the "suspended" state. You must reload such tables to get them back into the incremental update processing queue.
    Solution or workaround
    This is an indication that the system limits were reached. Check the system utilization and adjust it to the capacity of the system.
  8. High system utilization causes slower performance of IBM DB2 Analytics Accelerator tasks
    Summary
    Maintenance tasks might take longer than expected if the system utilization is high.
    Solution or workaround
    If the problem persists, restart the Netezza Platform Software (NPS) from the IBM DB2 Analytics Accelerator Console.
  9. Queries might fail if system utilization is high
    Summary
    A high system utilization might cause queries to fail occasionally with errors, such as ‘NZ IO error‘ or ‘SQL code = -904 00E7000E Bad data’ .
    Solution or workaround
    The system continues to operate. Subsequent queries succeed.
  10. A reload of a table set with many tables fails
    Summary
    A reload of a table set with thousands of tables might fail sporadically.
    Solution or workaround
    Split the table sets to be reloaded into smaller units and retry the operation.
  11. Load operation aborts with SIGABEND if the system utilization is very high
    Summary
    Occasionally, a load operation might end abnormally if the system utilization is very high.
    Solution or workaround
    Restart the load operation.
  12. Misleading warnings of type 'DSNX881I  -DI11 2001 W [...] SQL statement with task ID xxxxxxxx is running for more than xxxxxx seconds'
    Summary
    Under rare circumstances, a query might be continually reported as long-running, even though it was ended by a network outage or by a connection closure through the client application. These messages do not indicate that query processing is impacted in any way. The system stays operational and subsequent queries will run as expected.
    Solution or workaround
    The continual reporting of long-running tasks in DSNX88I messages stops after a restart of the accelerator. You can restart an accelerator from the IBM DB2 Analytics Accelerator Console.
  13. Abnormal ending of DB2 after -STOP ACCEL
    Summary
    In rare situations, DB2 ceases to operate with the following message after stopping an accelerator (either from IBM DB2 Analytics Accelerator Studio or by means of a -STOP ACCEL command from the DB2 command line):

    ABEND0C4 RC11 DSNRLLM1.DSNRPBCW+045A

    Solution or workaround
    APAR PI61661 addresses the problem.
  14. Incorrect table schema causes accelerator-only table (AOT) load failures
    Summary
    The SYSPROC.ACCEL_LOAD_TABLES stored procedure might fail with the message

    HLOU5724E The ACCEL_LOAD_TABLES stored procedure has failed.

    as it is loading data into an accelerator-only table ( AOT ) using the DB2 Analytics Accelerator Loader The failure mostly occurs when the stored procedure executes statements of the following type:

    INSERT INTO ... SELECT * FROM EXTERNAL <table-file>

    An incorrect table schema might be defined during the creation of an AOT by the DB2 Analytics Accelerator Loader. Such schemas show a column order that is different from the order in the CREATE TABLE statement.
    An incorrect schema might cause a failure of LOAD or INSERT operations. But even if the LOAD or INSERT operations are successful, the query results might be wrong.

    Solution or workaround
    APAR PI59910 addresses the problem.
  15. Insertion of integer and decimal values causes failure of IDT jobs
    Summary
    The insertion of integer and decimal values by an INSERT INTO ... VALUES statement might cause a failure of in-database transformation (IDT) jobs.

    For example, the following statement failed during tests:
    CREATE TABLE T1 (CDEC51 DECIMAL(5,1)) IN ACCELERATOR XYZ;
    INSERT INTO T1(CDEC51) VALUES(77247.04-69993);

    Symptoms: SQL codes like the following are returned:

    SQLCODE = -802, SQLSTATE = 22003, DATA EXCEPTION FROM IBM DB2 Analytics Accelerator TOKENS OVERFLOW ACCELERATOR NUMERIC DATA...

    Solution or workaround
    Use only decimal values instead of a mixture of integer and decimal values. The following statement, for example, will be successful:

    INSERT INTO T1(CDEC51) VALUES(77247.04-69993.0)

How to identify tables which should be reloaded after an installation of V5.1.0 PTF-2 (only if product level is "V5.1.0 GA" or "V5.1.0 PTF-1 without hot fix UI37271")

STEP 1: Identify the tables which could be affected
  • Use the sample code (for a stored procedure) in the technote at How to store information about accelerated tables in a DB2 for z/OS table to retrieve information about your accelerator-shadow tables. This information will be stored in a temporary DB2 table.
  • Run a simple SQL query against the replicationStatus and the lastLoadTimestamp columns of this temporary table to identify tables that must be reloaded. Follow the diagram at the end of this note to dertermine whether a table must be reloaded.

STEP 2: For all identified tables disable query acceleration, see Disabling query acceleration for tables

STEP 3: Install the V5.1.0 PTF-2

STEP 4: Automatic conversion
  • Immediately after the upgrade to the V5.1.0 PTF-2 an automatic conversion of data structures takes place.
  • Depending on the total amount of data to be converted, this might take more than 1 hour, during which the Netezza Platform Software (NPS) will be in the "Initializing" state. That is, the NPS cannot process requests.
STEP 5: Reloading tables
Within the first hour after installation of the new accelerator server code you might see a "DSNX881I - W 2004 ... Not all zone map records are consistent with the expected layout." message in the SYSLOG, which reports conversion failures. This is normal if the amount of data to be converted is high and due to a timeout mechanism. Please check the SYSLOG one hour after the installation of the accelerator server. If you see zero or maximum one DSNX88I-2004 message, then conversion has finished successfully and you can then start with full table reload of identified tables. If you see more than one DSNX88I-2004 messages, then check the SYSLOG again after 7 hours. If further messages show up, then conversion has a problem. In this case contact IBM support.
STEP 6: Enable query acceleration after full table reload see Enabling tables for query acceleration
Click on the image to enlarge it
Diagram to identify affected tables

Support for DB2 12 for z/OS

Please find known issues here.

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Document Information

Modified date:
08 August 2018

UID

swg27047893