ORA-00600 :[QKACON:FJswrwo]

Error code: Internal error code ORA-00600 [QKACON:FJswrwo],[3],[],[],[],[],[] occurs with connect by is an internal oracle error.
If this error occurs be alert you have only approx 20 Minutes to respond or ur DB can crash.

Solutions:
1.Upgrade to 11.1.0.6 or higher as this internal bug has been  fixed by oracle in version  11.1.0.6.

2.Try the below workarounds:(As recommended by Oracle support)

a) SET  the hidden parameter "_optimizer_connect_by_cost_based" = false;

• SQL>Alter session set  "_optimizer_connect_by_cost_based" = false;

or

b)Disable Hash Join:

• Alter session set "_hash_join_enabled"=false;
• Alter session set "_right_outer_hash_enable"=false;
• Alter session set "_gby_hash_aggregation_enabled"=false;

My prob got resolved using the workaround :  "_optimizer_connect_by_cost_based" = false;

To check the values of hidden parameters you can use the below Query:

SELECT x.inst_id,x.indx+1,ksppinm,ksppity,ksppstvl,ksppstdf,

DECODE(BITAND(ksppiflg/256,1),1,'TRUE','FALSE'),

DECODE(BITAND(ksppiflg/65536,3),1,'IMMEDIATE',2,'DEFERRED',3,'IMMEDIATE','FALSE'),

DECODE(BITAND(ksppstvf,7),1,'MODIFIED',4,'SYSTEM_MOD','FALSE'),

DECODE(BITAND(ksppstvf,2),2,'TRUE','FALSE'),

ksppdesc

FROM x$ksppi x,

x$ksppcv y

WHERE (x.indx = y.indx)

/*and (translate(ksppinm,'_','#') not like '#%'

OR (TRANSLATE(ksppinm,'_','#') LIKE '#%'AND ksppstdf = 'TRUE'))*/

ORDER BY 3;

Below you can find the list of some useful oracle hidden params:

Parameter Name	Details
_B_TREE_BITMAP_PLANS	This parameter’s default value changed from FALSE in Oracle 8i to TRUE in Oracle 9i. This can lead to an undesirable impact on performance thus this should be set to FALSE.
_INDEX_JOIN_ENABLED	This parameter’s default value changed from FALSE in Oracle 8i to TRUE in Oracle 9i. This can lead to an undesirable impact on performance thus this should be set to FALSE.
_KGL_LARGE_HEAP_WARNING_THRESHOLD	This parameter was introduced in 10G Release 2.  This will eliminate the following error message: Memory Notification: Library Cache Object loaded into SGA Heap size XXXXK exceeds notification threshold For example set it as follows: ALTER SYSTEM SET "_KGL_LARGE_HEAP_WARNING_THRESHOLD" = 8388608 SCOPE = SPFILE;
QUERY_REWRITE_ENABLED	In order to make use of the Function Based Indexes this parameter must be set to TRUE.
OPTIMIZER_SECURE_VIEW_MERGING	This parameter was introduced in 10G Release 2.  Setting this parameter to FALSE is required otherwise it is possible for the optimizer to create different execution plans for identical statements on identical objects issued from different user schemas.
_OPTIMIZER_CONNECT_BY_COST_BASED	Setting this parameter to FALSE is required for a workaround to the Oracle error ORA-600 [qkacon:FJswrwo].