Oracle ORA-600 [kdsgrp1]

Format: ORA-600 [kdsgrp1]

VERSIONS:

versions 10.1 and above

DESCRIPTION:

This error was introduced in 10g with the fix to Bug 2442351, it provides

for an extra health check on a block, we detected a null row header,

see Note:2442351.9 for more information.

Error may be caused by:

Case 1. A row referenced in an index that does not exist in the table.

Case 2. An unexistent rowid pointed by a chained row.

Trace Examples:

Case 1. Mismatch between table and index:

====================================================

Trace file has:

row 02433566.13 continuation at

file# 9 block# 210278 slot 20 not found

The file=9 block=210278 is rdba=0x02433566 which was taken from an index:

row#3[7549] flag: ------, lock: 0, len=85, data:(6): 02 43 35 66 00 14

But the slot 20 does not exist in the table block:

tab 0, row 1, @0x1e62

tl: 2 fb: --HDFL-- lb: 0x3

tab 0, row 12, @0x191a

tl: 2 fb: --HDFL-- lb: 0x1

tab 0, row 17, @0x1675

tl: 2 fb: --HDFL-- lb: 0x2

tab 0, row 21, @0x1459

tl: 2 fb: --HDFL-- lb: 0x4

ORA-1499 may be produced by analyze:

analyze table <table name> validate structure cascade;

Case 2. A row points to another rowid which does not exist (Chained row does not exist).

============================================================================================

Trace file has:

row 1186b11a.ffffffff continuation at

file# 70 block# 441621 slot 1 not found

It means that row with rdba 0x1186b11a continues in file# 70 block# 441621 slot 1.

But the information in file# 70 block# 441621 slot 1 does not exist. It is:

tab 0, row 16, @0xd7f ---> This is the slot with the problem.

tl: 29 fb: -------- lb: 0x0 cc: 11

nrid: 0x1186bd15.1 ---> It points to rdba=0x1186bd15 slot 1 (file# 70 block# 441621 slot 1) but that row does not exist in that block.

For this case ANALYZE TABLE .. VALIDATE STRUCTURE is not detecting this logical corruption

Referece Bug 6858313

Run an export (exp) or Full Table Scan to identify if there is a permanent invalid chained row.

Workaround for Case 2:

The row producing the ORA-600 [kdsgrp1] can be skipped by setting the Event 10231

FUNCTIONALITY:

Kernel Data layer Seek/Scan

IMPACT:

PROCESS FAILURE

POSSIBLE PHYSICAL CORRUPTION