ORA-600 [KCBLASM_1], [103] on Patchset 10.2.0.5

During routine alert.log check control I spotted several ORA-600 errors:

ORA-00600: internal error code, arguments: [kcblasm_1], [103]

It is a known issue introduced with 10.2.0.5. This platform generic bug (7612454) is a regression bug introduced in Patchset 10.2.0.5 according to MOS note:

Bug 7612454 – More “direct path read” operations / OERI:kcblasm_1 [ID 7612454.8]

Obviously, bug 7612454 causes performance problem with direct path reads, compared to performance from before (10.2.0.5). [Right now, I can’t confirm how severe performance impact is, because no one so far reported a performance problem or any crashes.]

Since no workaround was mentioned in above MOS note I searched further and found related note that highlights the problem a bit more:

ORA-600 [KCBLASM_1] RUNNING A QUERY WITH HASH GROUP BY [ID 848094.1]

At the time of this writing I’ll probably disable group by hash aggregation at instance level (_gby_hash_aggregation_enabled = false), if the problem becomes severe. So far, this bug is more of an annoyance than a show stopper – but I feel better being prepared with a workaround. I hope we’ll not hit the case when neither setting _gby_hash_aggregation_enabled = false nor _hash_join_enabled=false helped as a workaround, as described in MOS note Bug 9918715: ORA-00600 [KCBLASM_1] ERROR.

The second suggested workaround, upgrade to 11.2, is (of course) out of the question at this time. Besides, who can guarantee us that we will not hit some XY regression bug in 11.2 the day after we go in production with 11.2! ;-)

What to say for the end, 10gR2 deserves to stay written in my black book with golden letters as being the buggiest version ever released by Oracle. Someone can argue that bugs goes hand in hand with features, software business as usual; I had to say, with every new grey hair I have less and less tolerance to excuses like this.

Posted on 03.11.2010, in Oracle and tagged . Bookmark the permalink. 1 Comment.

  1. Patch 3 for Windows x64/x86
    At the end of October 2010 Oracle released Patch 3 on top of 10.2.0.5, for Windows x64 (patch#10196896) and Windows x86 (patch#10196895) where bug 7612454 is listed as being fixed. Now, I know what I’ll be doing over the weekend. :(

    [Update November 5th, 2010 — don’t blindly follow instructions below – it’s for my own use!]

    -- Read and apply preinstallation instructions from Readme.html, then...
    -- cleanly shutdown database and stop Oracle services
    set ORACLE_HOME=X:\ORACLE\ORA10
    set PATH=%ORACLE_HOME%\Opatch;%PATH%
    cd 10196895
    opatch apply
    
    start OracleServiceORAX
    
    cd %ORACLE_HOME%\BUNDLE\Patch3
    sqlplus /nolog
    connect / as sysdba
    startup
    @catcpu.sql
    select * from registry$history;
    -- check logfile %ORACLE_HOME%\cfgtoollogs\catbundle
    -- if necessary run 
    ?\rdbms\admin\utlprp.sql 0
    

    Note that even though you downloaded patch 3 archive for Windows x64 (p10196896_10205_MSWIN-x86-64.zip) the directory inside zip is actually named 10196895 (the same as for Patch 3 for Windows x86). You can ignore this typo, opatch lsinventory will show correct patch number:

    cmd> opatch lsinventory
    Invoking OPatch 10.2.0.5.0
    
    Oracle Interim Patch Installer version 10.2.0.5.0
    Copyright (c) 2010, Oracle Corporation.  All rights reserved.
    
    .....
    .....
    Interim patches (1) :
    
    Patch  10196896    : applied on Fri Nov 05 10:03:49 CET 2010
    Unique Patch ID:  13076038
       Created on 15 Oct 2010, 06:49:42 hrs
       Bugs fixed:
         10196896, 10080735, 5519322, 6768114, 6904068, 7045446, 7452759, 7612454
         8684595, 8811401, 9109487, 9320130, 9337325, 9362218, 9390484, 9548269
         9770451, 10155844, 9047975, 8663644, 7708267, 6086930, 9539556, 9355794
         8264642, 9495669, 6975402, 9659614, 9387574, 9320786, 9793452, 9024737
         9196440, 8970313, 9308296, 9663844, 10099855, 6402302, 7519406, 8224558
         8487143, 8544696, 8546356, 8664189, 8996060, 9261837, 9577921, 9586637
         9646836, 9683239, 9711859, 9713537, 9714832, 9726739, 9747153, 9772888, 9870614