ORA-00600: Internal Error Code Arguments – Complete Oracle DBA Troubleshooting Guide

The ORA-00600: internal error code, arguments error is one of the most critical and complex Oracle Database internal errors encountered by DBAs and developers.

This error indicates that Oracle Database has encountered an unexpected internal condition or inconsistency at the kernel level. Unlike common Oracle errors such as ORA-01017 or ORA-01555, ORA-00600 is an internal Oracle software error that often requires deep troubleshooting and analysis.

In many cases, ORA-00600 errors are related to:

Corrupted indexes
Data block corruption
Oracle bugs
Memory inconsistencies
Query optimizer problems
Corrupted objects
Hardware or I/O issues

In this complete Oracle DBA guide, you will learn:

What ORA-00600 means
Why the error occurs
How to troubleshoot ORA-00600
How to identify corrupted indexes
How to analyze Oracle trace files
How to fix ORA-00600 [kdsgrp1]
Best practices to prevent internal Oracle errors

What is ORA-00600?

ORA-00600 is a generic Oracle internal error generated when the Oracle kernel detects an unexpected low-level condition.

Oracle officially describes ORA-00600 as an internal software exception error.

The error format usually appears like this:

ORA-00600: internal error code, arguments: [kdsgrp1], [], [], []

The first argument inside brackets is extremely important because it identifies the internal Oracle component or problem area.

Error Message

ORA-00600: internal error code, arguments: [kdsgrp1], [], [], [], [], [], []

ORA-00600

Quick Solution

Quick Fix: Check Oracle alert logs and trace files, identify corrupted indexes or objects, validate table/index structures, and rebuild corrupted indexes.

Understanding ORA-00600 [kdsgrp1]

The [kdsgrp1] argument is commonly associated with index corruption or data access inconsistencies.

In many production environments, this error occurs during:

Large UPDATE statements
Heavy DML operations
Index scans
Batch processing jobs
Data migration tasks

In your original scenario, the issue occurred while updating approximately 30,000 records.

Common Causes of ORA-00600

Corrupted indexes
Corrupted database blocks
Oracle software bugs
Failed memory checks
Storage or hardware issues
Improper recovery operations
I/O subsystem problems
Corrupted statistics
Invalid optimizer execution plans

Oracle experts and DBAs frequently identify index corruption as one of the major reasons for ORA-00600 [kdsgrp1].

How Oracle Writes ORA-00600 Errors

Whenever ORA-00600 occurs, Oracle writes diagnostic information into:

Alert log file
Trace files
Incident dump files

These files are essential for identifying the root cause.

Step-by-Step ORA-00600 Troubleshooting

1. Check Oracle Alert Log

The first step is to review the Oracle alert log.

Locate the alert log file:

$ORACLE_BASE/diag/rdbms

Search for ORA-00600 entries and identify:

Timestamp
Session information
Trace file location

2. Open Trace File

The alert log usually references a trace (.trc) file.

Open the trace file and search for:

Plan Table

This section often reveals the SQL query causing the issue.

3. Identify Problematic Query

Analyze the SQL statement mentioned in the trace file.

Large update or select statements involving corrupted indexes commonly trigger ORA-00600.

4. Validate Table Structure

Validate all related tables using:

ANALYZE TABLE table_name VALIDATE STRUCTURE CASCADE;

Example:

ANALYZE TABLE employees VALIDATE STRUCTURE CASCADE;

This checks for structural corruption.

5. Validate Indexes

Now validate indexes associated with the affected tables.

ANALYZE INDEX index_name VALIDATE STRUCTURE;

Example:

ANALYZE INDEX emp_idx VALIDATE STRUCTURE;

In many ORA-00600 [kdsgrp1] cases, the validation itself fails and returns ORA-00600 again.

6. Rebuild or Recreate Corrupted Index

If an index is corrupted, rebuild or recreate it.

Option 1: Rebuild Index

ALTER INDEX emp_idx REBUILD;

Option 2: Drop and Recreate Index

DROP INDEX emp_idx;

CREATE INDEX emp_idx
ON employees(employee_id);

In your original case, recreating the corrupted index resolved the issue successfully.

Real-World Production Scenario

A production Oracle 11gR2 database running on Enterprise Linux generated ORA-00600 [kdsgrp1] during a batch update job processing 30,000 records.

The update worked correctly for individual records but failed during bulk execution.

The DBA analyzed the Oracle trace file and identified a corrupted index involved in the execution plan.

After validating indexes and rebuilding the corrupted index, the update completed successfully.

ORA-00600 Flow Chart

Additional Oracle Diagnostic Queries

Check Invalid Objects

SELECT owner, object_name, object_type
FROM dba_objects
WHERE status='INVALID';

Check Corrupted Blocks

SELECT *
FROM v$database_block_corruption;

Check Alert Log Errors

adrci> show alert -tail 100

Oracle Support Recommendation

Oracle officially recommends collecting diagnostic information and opening a support request for persistent ORA-00600 issues.

Oracle also provides ORA-00600 troubleshooting tools through My Oracle Support (MOS).

Best Practices to Prevent ORA-00600

Keep Oracle patches updated
Monitor storage and I/O health
Validate indexes periodically
Monitor alert logs regularly
Avoid abrupt shutdowns
Use RMAN backups consistently
Monitor database corruption proactively
Perform regular health checks

Common DBA Mistakes

Ignoring alert log warnings
Deleting trace files without analysis
Ignoring index corruption symptoms
Performing unsupported recovery procedures
Running production updates without backups

ORA-00600 and Oracle Bugs

Many ORA-00600 errors are related to Oracle software bugs.

Oracle Support and DBA communities frequently recommend checking MOS notes and patch availability. Community discussions also indicate that some ORA-00600 variants are fixed in newer Oracle patch sets.

Frequently Asked Questions (FAQ)

What causes ORA-00600?

ORA-00600 occurs when Oracle detects an unexpected internal software condition, often related to corruption, bugs, or memory inconsistencies.

Is ORA-00600 serious?

Yes. ORA-00600 is considered a critical Oracle internal error and should be investigated immediately.

Can index corruption cause ORA-00600?

Yes. Corrupted indexes are one of the most common causes of ORA-00600 [kdsgrp1].

How do I locate Oracle trace files?

$ORACLE_BASE/diag/rdbms

Should I contact Oracle Support?

Yes, especially for recurring ORA-00600 errors or database crashes.

👉 Check our complete guide: Oracle Error Codes Guide

Conclusion

The ORA-00600 internal error is one of the most challenging Oracle Database issues faced by DBAs.

Although the error may appear complex, systematic troubleshooting using alert logs, trace files, table validation, and index analysis can often identify the root cause quickly.

In many ORA-00600 [kdsgrp1] cases, rebuilding corrupted indexes successfully resolves the issue.

Regular database maintenance, monitoring, backups, and proactive health checks are essential for preventing serious Oracle internal errors in production environments.

Your comments, especially which will help us improve the functionality, will be greatly appreciated.

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ORA-00600: internal error code arguments: [kdsgrp1]