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undo tablespace auto extenadable=yes

JhilSep 27 2015 — edited Sep 30 2015

Hello everyone

>> Different points for same process - i am highly confused.

1)  Docs clearly says ,  If undo tablespace with the AUTOEXTEND option enabled, the database attempts to honor the minimum retention period specified by UNDO_RETENTION  **

2)   If the undo tablespace is configured with the AUTOEXTEND option, the database tunes the undo retention period to be somewhat longer than the longest-running query on the system at that time.

      Again, this tuned retention period can be greater than the  specified minimum retention period.  **

      source : http://docs.oracle.com/cd/B19306_01/server.102/b14231/undo.htm

SYS>show parameter undo;

NAME                                 TYPE        VALUE

------------------------------------ ----------- ------------------------------

undo_management                      string      AUTO

undo_retention                            integer     2800

undo_tablespace                         string      UNDOTBS1

SYS>select tablespace_name , file_name , AUTOEXTENSIBLE from dba_data_files where tablespace_name like 'UNDOTBS1';

TABLESPACE_NAME                FILE_NAME              AUT

------------------------------ ---------------------- ---

UNDOTBS1                       /u03/undotbs1.dbf               YES

Can anyone clarify , why oracle states two different points for same process ?

1 )  If undo tablespace with the AUTOEXTEND option enabled, the database attempts to honor the minimum retention period specified by UNDO_RETENTION

2)   If the undo tablespace is configured with the AUTOEXTEND option, the database tunes the undo retention period to be somewhat longer than the longest-running query on the system at that time.

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