ORA-1555 - UNDO_RETENTION is silently ignored if the LOB resides in a MSSM tablespace (Doc ID 800386.1)

Symptoms

• ORA-1555/ORA-22924 may occur when accessing LOB columns, even when the LOB RETENTION seems to be sufficient.

This may occur when LOB column resides in a MSSM (Manual Segment Space Management) tablespace.

-- Verify Segment Management

select tablespace_name, extent_management,  segment_space_management
from dba_tablespaces
where tablespace_name in
  (select tablespace_name from dba_segments
   where owner='TEST' and segment_name='TAB1');

TABLESPACE_NAME                EXTENT_MAN SEGMEN
------------------------------ ---------- ------
TESTCASE                            LOCAL MANUAL <==  

• To check whether tablespace is using Manual verify whether PCTVERSION or RETENTION is used, execute:

-- Verify LOB retention parameter
select column_name, pctversion, retention
from dba_lobs
where owner = 'TEST' and table_name ='TAB1';

COLUMN_NAME   PCTVERSION  RETENTION
------------- ---------- ----------
DATA                          86400 <==

. 

Changes

LOB column is stored on MSSM tablespace.

Cause

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