Corrupt block relative dba message in the Alert Log - Definition and Solution

What is the meaning of message "Corrupt block relative dba..." in the alert log?

message describing the block corruption:

Bad header found during buffer read
Data in bad block:
type: 2 format: 2 rdba: 0x21008dd0
last change scn: 0x0006.12114f8e seq: 0x37 flg: 0x04
spare1: 0x0 spare2: 0x0 spare3: 0x0
consistency value in tail: 0x4f8e0237
check value in block header: 0x6e5b
computed block checksum: 0x0
Reread of rdba: 0x3d808dd0 (file 246, block 36304) found same corrupted data
Errors in file /testsite/testdb/db/tech_st/11.1.0/admin/TEST_erptestappldb/diag/rdbms/test/TEST/trace/TEST_s000_11075614.trc
(incident=31537):
ORA-01578: ORACLE data block corrupted (file # 246, block # 36304)
ORA-01110: data file 246: '/testsite/testdb/db/apps_st/data/a_txn_data47.dbf'
Incident details in: /testsite/testdb/db/tech_st/11.1.0/admin/TEST_erptestappldb/diag/rdbms/test/TEST/incident/incdir_31537/T
EST_s000_11075614_i31537.trc
Wed Jun 28 11:42:12 2017
Corrupt Block Found
TSN = 10, TSNAME = APPS_TS_TX_DATA
RFN = 246, BLK = 36304, RDBA = 1031835088
OBJN = 87982, OBJD = 87982, OBJECT = OE_ORDER_HEADERS_ALL, SUBOBJECT =
SEGMENT OWNER = ONT, SEGMENT TYPE = Table Segment
Wed Jun 28 11:42:25 2017
Non critical error ORA-48913 caught while writing to trace file "/testsite/testdb/db/tech_st/11.1.0/admin/TEST_erptestappldb/
diag/rdbms/test/TEST/incident/incdir_31537/TEST_s000_11075614_i31537.trc"
Error message: ORA-48913: Writing into trace file failed, file size limit [10485760] reached
Writing to the above trace file is disabled for now on... 

Solution:

The corruption you are finding is misplaced block, which is a physical corruption introduced by the underlying system.

Corrupt block relative dba: 0x3d808dd0 (file 246, block 36304)
Bad header found during buffer read
Data in bad block:
type: 2 format: 2 rdba: 0x21008dd0 rdba: 0x21008dd0 != dba: 0x3d808dd0
last change scn: 0x0006.12114f8e seq: 0x37 flg: 0x04
spare1: 0x0 spare2: 0x0 spare3: 0x0
consistency value in tail: 0x4f8e0237
check value in block header: 0x6e5b
computed block checksum: 0x0
Reread of rdba: 0x3d808dd0 (file 246, block 36304) found same corrupted data 

This is fully solvable by blockrecovery operations. 

If RMAN backup is available and all archivelogs, than please run:

RMAN>recover corruption list;

Otherwise, the data in the affected blocks is lost and segments will need to be recreated.

To evaluate the overall database status, you can use:

RMAN> backup validate check logical database;

NOTE:
=====
This command will succeed if DB is running in ARCHIVELOG mode.
. If DB in NOARCHIVELOG mode, then this RMAN command *Must* be run against the database in MOUNT state.
. If you try to this RMAN command against an open DB running NOARCHIVELOG mode the following error will occur:

-> RMAN-03009: failure of backup command on d1 channel at 12/07/2009 18:55:25
-> ORA-19602: cannot backup or copy active file in NOARCHIVELOG mode

After RMAN validate finishes, the view v$database_block_corruption will be populated with all the affected blocks.

To identify the affected objects, below queries can be used:

set pagesize 2000
set linesize 280
SELECT e.owner, e.segment_type, e.segment_name, e.partition_name, c.file#
, greatest(e.block_id, c.block#) corr_start_block#
, least(e.block_id+e.blocks-1, c.block#+c.blocks-1) corr_end_block#
, least(e.block_id+e.blocks-1, c.block#+c.blocks-1)
- greatest(e.block_id, c.block#) + 1 blocks_corrupted
, corruption_type description
FROM dba_extents e, v$database_block_corruption c
WHERE e.file_id = c.file#
AND e.block_id <= c.block# + c.blocks - 1
AND e.block_id + e.blocks - 1 >= c.block#
UNION
SELECT s.owner, s.segment_type, s.segment_name, s.partition_name, c.file#
, header_block corr_start_block#
, header_block corr_end_block#
, 1 blocks_corrupted
, corruption_type||' Segment Header' description
FROM dba_segments s, v$database_block_corruption c
WHERE s.header_file = c.file#
AND s.header_block between c.block# and c.block# + c.blocks - 1
UNION
SELECT null owner, null segment_type, null segment_name, null partition_name, c.file#
, greatest(f.block_id, c.block#) corr_start_block#
, least(f.block_id+f.blocks-1, c.block#+c.blocks-1) corr_end_block#
, least(f.block_id+f.blocks-1, c.block#+c.blocks-1)
- greatest(f.block_id, c.block#) + 1 blocks_corrupted
, 'Free Block' description
FROM dba_free_space f, v$database_block_corruption c
WHERE f.file_id = c.file#
AND f.block_id <= c.block# + c.blocks - 1
AND f.block_id + f.blocks - 1 >= c.block#
order by file#, corr_start_block#;