Oracle ORA-00600 Error: Causes and Solutions Complete Guide

ORA-00600: Oracle Internal Error – What It Means and How to Fix It

ORA-00600 is Oracle's generic internal error code, thrown directly by the Oracle kernel when it detects an unexpected condition it cannot handle gracefully. Unlike user-facing errors such as ORA-00942 (table not found) or ORA-01017 (invalid credentials), this error signals a problem within Oracle's own engine. The bracketed arguments in the error message — for example, ORA-00600: internal error code, arguments: [12700], [1], ... — are your most critical diagnostic clue.

Top 3 Causes

1. Known Oracle Software Bug (Missing Patch)

The most common cause is an unpatched Oracle bug. Oracle regularly releases Release Updates (RU) and Patch Set Updates (PSU) to fix known internal issues. Running an outdated patch level significantly increases the risk of hitting a documented bug that triggers ORA-00600.

-- Check current Oracle version and installed patches
SELECT * FROM V$VERSION;

SELECT PATCH_ID, PATCH_UID, VERSION, ACTION, STATUS, ACTION_TIME
FROM   DBA_REGISTRY_SQLPATCH
ORDER  BY ACTION_TIME DESC;

Search the exact argument values on My Oracle Support (MOS) — most ORA-00600 instances map to a specific bug ID with an available patch.

2. Data Block Corruption

Physical or logical corruption in a datafile can cause Oracle's internal block validation routines to fail, raising ORA-00600. Storage failures, incomplete I/O operations, or botched recovery procedures are typical culprits.

-- Validate all datafiles with RMAN (run from RMAN prompt)
-- RMAN> BACKUP VALIDATE CHECK LOGICAL DATABASE;

-- Check for detected corrupt blocks
SELECT FILE#, BLOCK#, BLOCKS, CORRUPTION_TYPE
FROM   V$DATABASE_BLOCK_CORRUPTION
ORDER  BY FILE#, BLOCK#;

-- Recover corrupt blocks automatically (RMAN)
-- RMAN> RECOVER CORRUPTION LIST;

3. SGA / Memory Corruption

Corruption in the Shared Pool or Buffer Cache can cause Oracle to dereference invalid memory pointers, resulting in ORA-00600. Underscore (hidden) parameter misconfigurations, OS-level memory instability, or extreme memory pressure are frequent contributors.

-- Review SGA component sizes
SELECT COMPONENT, CURRENT_SIZE/1024/1024 AS SIZE_MB
FROM   V$SGA_DYNAMIC_COMPONENTS
ORDER  BY CURRENT_SIZE DESC;

-- Flush shared pool as a temporary workaround
ALTER SYSTEM FLUSH SHARED_POOL;

-- Check for non-default hidden parameters (underscore params)
SELECT NAME, VALUE, DESCRIPTION
FROM   V$PARAMETER
WHERE  ISDEFAULT = 'FALSE'
  AND  NAME LIKE '\_%' ESCAPE '\'
ORDER  BY NAME;

Quick Fix Solutions

Step 1 – Capture the error details immediately.

-- Find recent ORA-00600 occurrences in the alert log
SELECT ORIGINATING_TIMESTAMP, MESSAGE_TEXT
FROM   V$DIAG_ALERT_EXT
WHERE  MESSAGE_TEXT LIKE '%ORA-00600%'
ORDER  BY ORIGINATING_TIMESTAMP DESC
FETCH  FIRST 10 ROWS ONLY;

-- Locate the trace file directory
SELECT VALUE FROM V$DIAG_INFO WHERE NAME = 'Diag Trace';

Step 2 – Isolate the offending SQL and apply a hint-based workaround.

-- Force a full table scan to bypass a bad index access path
SELECT /*+ FULL(t) NO_MERGE */ *
FROM   problematic_table t
WHERE  status = 'ACTIVE';

-- Disable a specific optimizer feature at session level (temporary only)
ALTER SESSION SET "_complex_view_merging" = FALSE;
ALTER SESSION SET "_optimizer_null_aware_antijoin" = FALSE;

Step 3 – Open a Service Request with Oracle Support, providing the trace file, alert log excerpt, exact argument values, and the output of V$VERSION and DBA_REGISTRY_SQLPATCH.

Prevention Tips

1. Stay current on Oracle patches.
Apply Oracle's quarterly Release Updates (RU). Most ORA-00600 bugs encountered in production have already been fixed in a newer patch. Schedule patch maintenance windows at least twice a year.

2. Automate block integrity checks.
Use RMAN to validate your database weekly and monitor V$DATABASE_BLOCK_CORRUPTION daily.

-- Daily corruption monitoring query (add to your monitoring script)
SELECT SYSDATE        AS checked_at,
       COUNT(*)       AS corrupt_block_count
FROM   V$DATABASE_BLOCK_CORRUPTION;

Combine this with OS-level storage health checks (disk SMART data, SAN logs) to catch hardware issues before they escalate into ORA-00600 events.

Related Errors

Bottom line: ORA-00600 is never something to ignore or simply restart your way past. Capture the trace file, match the arguments on MOS, and engage Oracle Support early — the sooner you act, the less data and downtime risk you face.

📖 Want a more detailed guide?
Check out the full in-depth version (Korean) on oraerror.com — includes detailed analysis, additional SQL examples, and prevention tips.