ORA-00600: internal error code, arguments: [ktbdchk1: bad dscn]

Cause: This Errors May Occur after a switchover Physical Standby database, and it is due to Oracle Bug 8895202. 

Solution:  Apply the patch where this issue is fixed , Patch 8895202 or Patch Sets >= 11.2.0.2 or Patch Bundles >= 11.1.0.7. If Your database version is >=11.2.0.2 then just change the parameter _ktb_debug_flags to 8. There is no danger in keeping _ktb_debug_flags=8. It gets only activated by invalid scn in itl.

After change the parameter analyze the object which has been affected.

bash-4.3$ sqlplus "/as sysdba"

SQL*Plus: Release 11.2.0.4.0 Production on Tue Sep 26 14:31:11 2017

Copyright (c) 1982, 2013, Oracle.  All rights reserved.


Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, Real Application Clusters, Automatic Storage Management, Oracle Label Security,
OLAP, Data Mining, Oracle Database Vault and Real Application Testing options

SQL> alter system set "_ktb_debug_flags"=8 scope=both sid='*';

System altered.

SQL> EXIT
Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, Real Application Clusters, Automatic Storage Management, Oracle Label Security,
OLAP, Data Mining, Oracle Database Vault and Real Application Testing options
bash-4.3$
bash-4.3$



ORA-01555 caused by SQL statement below (SQL ID: 89w0nk4mvs89k, Query Duration=0 sec, SCN: 0x0b0e.183c53aa):

Dump continued from file: /u01/app/oracle/diag/rdbms/erpdcdb/erpdcdb1/trace/erpdcdb1_ora_7798850.trc
ORA-00600: internal error code, arguments: [ktbdchk1: bad dscn], [], [], [], [], [], [], [], [], [], [], []

========= Dump for incident 5041023 (ORA 600 [ktbdchk1: bad dscn]) ========
----- Beginning of Customized Incident Dump(s) -----
[ktbdchk] -- ktbgcl4 -- bad dscn
dependent scn: 0x0b0e.6ada21f5 recent scn: 0x0b0e.183bdd5c current scn: 0x0b0e.183bdd5c
----- End of Customized Incident Dump(s) -----

ANALYZE TABLE TABLE_NAME VALIDATE STRUCTURE CASCADE;

Dump continued from file: /u01/app/oracle/diag/rdbms/erpdcdb/erpdcdb2/trace/erpdcdb2_ora_5767956.trc
ORA-00600: internal error code, arguments: [2663], [2830], [698760342], [2830], [1792623805], [], [], [], [], [], [], []

========= Dump for incident 2720876 (ORA 600 [2663]) ========

*** 2017-09-26 13:52:19.908
dbkedDefDump(): Starting incident default dumps (flags=0x2, level=3, mask=0x0)
----- Current SQL Statement for this session (sql_id=2pbup9vshvk0u) -----
ANALYZE TABLE TABLE_NAME VALIDATE STRUCTURE CASCADE;

ORA-12519: TNS:no appropriate service handler found

ORA-12519: TNS: no appropriate service handler found

Cause: Number of session and process reached the MAX_UTILIZATION level when listener find the current number of connections has reached maximum load it may set the state of the service handler for an instance to "blocked" and begin refusing incoming client connections.

Solution: Check the value of process parameter and increase the value of the parameter.


[grid@DB ~]$ lsnrctl services

LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 24-SEP-2017 13:32:38

Copyright (c) 1991, 2013, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
Services Summary...
Service "+ASM" has 1 instance(s).
  Instance "+ASM", status READY, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:1158 refused:0 state:ready
         LOCAL SERVER
Service "SPFTLDB" has 1 instance(s).
  Instance "SPFTLDB", status READY, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:73880 refused:0 state:blocked
         LOCAL SERVER
Service "SPFTLDBXDB" has 1 instance(s).
  Instance "SPFTLDB", status READY, has 1 handler(s) for this service...
    Handler(s):
      "D000" established:0 refused:0 current:0 max:1022 state:ready
         DISPATCHER <machine: DB.spftl.com, pid: 18815>
         (ADDRESS=(PROTOCOL=tcp)(HOST=db.spftl.com)(PORT=43078))
The command completed successfully

SQL> show parameter processes

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
aq_tm_processes                      integer     1
db_writer_processes                  integer     3
gcs_server_processes                 integer     0
global_txn_processes                 integer     1
job_queue_processes                  integer     1000
log_archive_max_processes            integer     4
processes                            integer     150
SQL> ALTER SYSTEM SET processes=1000 SCOPE=SPFILE;

System altered.

SQL>

Bounce the database.