Category: Materialized View

Slow Complete Refresh of Materialized View in Oracle Database

The status of the materialized view with 30 million records is ‘UNUSABLE’, so a complete refresh is required to fix this problem .

The complete refresh process ran for 3 hours, then we have to kill it.

SQL>  execute dbms_mview.refresh(MVIEW1','c');



^C^C
^C^C^C^C^C^C^C

BEGIN dbms_mview.refresh('MVIEW1','c'); END;

*
ERROR at line 1:
ORA-12152: TNS:unable to send break message


Elapsed: 03:11:16.16

There are a couple of following ways to speed up this complete refresh, one of them only takes 27 minutes.

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Change Materialized View Refresh Mode Makes Materialized View Unusable

The materialized view was in good status until when changes its refresh mode:

SQL>  select MVIEW_NAME,REFRESH_MODE,REFRESH_METHOD,STALENESS 
      dba_mviews 
      where mview_name='MVIEW1';

MVIEW_NAME     REFRES     REFRESH_  STALENESS  
-------------- ---------- --------- ----------
MVIEW1         COMMIT     FAST      FRESH    


SQL> alter materialized view MVIEW1 refresh fast on demand;



SQL>  select MVIEW_NAME,REFRESH_MODE,REFRESH_METHOD,STALENESS 
      dba_mviews 
      where mview_name='MVIEW1';

MVIEW_NAME     REFRES     REFRESH_  STALENESS  
-------------- ---------- --------- ------------------
MVIEW1         COMMIT     FAST      COMPILATION_ERROR 

 

SQL> alter materialized view MVIEW1 compile;

Materialized view altered.


SQL>  select MVIEW_NAME,REFRESH_MODE,REFRESH_METHOD,STALENESS 
      dba_mviews 
      where mview_name='MVIEW1';

MVIEW_NAME     REFRES     REFRESH_  STALENESS  
-------------- ---------- --------- --------------------
MVIEW1         COMMIT     FAST      UNUSABLE

It might be a bug ? not quite sure why. In this situation, the materialized view has to be refreshed completed or rebuilt.

Materialized View Refresh Group

This post demonstrates how to create and maintain a materialized view refresh group in Oracle database.

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Check Last Refresh Date and Time of Oracle Materialized Views

SQL>SELECT
           OWNER,
           MVIEW_NAME,
           REFRESH_MODE,
           REFRESH_METHOD,
           TO_CHAR(LAST_REFRESH_END_TIME,'YYYYMMDD-HH24:MI:SS'),
           STALENESS 
    FROM
           DBA_MVIEWS;

“ORA-01031: insufficient privileges” from SYS User Creating Materialized Views

A client try to create a materialized view by SYS user with the following errors:

SQL> show user
USER is "SYS"

SQL> create materialized view USER1.MV_TABLE2
BUILD IMMEDIATE
REFRESH FAST ON commit
with primary key
as select * from USER2.TABLE2;


ERROR at line 6:
ORA-01031: insufficient privileges

SOLUTION

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