REFRESH

REFRESHE is used to refresh a specified materialized view.

Syntax

DBMS_MVIEW.REFRESH (
    mv_name             IN    VARCHAR(65535),
    method              IN    VARCHAR(65535) DEFAULT NULL,
    refresh_parallel    IN    INT DEFAULT 0,
    nested              IN    BOOLEAN DEFAULT FALSE,
    nested_refresh_mode IN    VARCHAR DEFAULT NULL
);

Parameter description

info

Non-nested materialized views do not support cascading refresh. Therefore, specifying the nested and nested_refresh_mode parameters is meaningless. By default, they are refreshed independently.

Parameter	Description
mv_name	The name of the materialized view to be refreshed.
method	The refresh strategy of the materialized view. You can specify a default refresh strategy when you create a materialized view. Valid values: 'f' or 'F': fast refresh. '?': force refresh. 'C' or 'c': complete refresh. 'A' or 'a': complete refresh.
refresh_parallel	The concurrency of the refresh operation, that is, the number of threads that execute the refresh operation at the same time. The default value is 0
nested	The refresh mode of the nested materialized view. Valid values: FALSE: default value, indicating that the nested materialized view is refreshed independently. TRUE: indicating that the nested materialized view is cascading refreshed.
nested_refresh_mode	The refresh mode of the nested materialized view. Valid values: When the nested parameter is specified as FALSE, specifying the nested_refresh_mode parameter will result in an error. When the nested parameter is specified as TRUE: Specify the nested_refresh_mode parameter as follows: inconsistent: indicating that the nested materialized view is cascading refreshed in an inconsistent manner. consistent: indicating that the nested materialized view is cascading refreshed in a consistent manner. By default, the nested materialized view is cascading refreshed in an inconsistent manner.

Examples

• Independent refresh:

  • Specify only the mv_name parameter.

    CALL DBMS_MVIEW.REFRESH('mv1');

  • Specify the mv_name parameter and set the nested parameter to false.

    CALL DBMS_MVIEW.REFRESH('mv1', nested=> false);

• Cascading inconsistent refresh:

  • Specify the mv_name parameter and set the nested parameter to true. Do not specify the nested_refresh_mode parameter.

    CALL DBMS_MVIEW.REFRESH(
        'mv1',   nested=> true);

  • Specify the mv_name parameter and set the nested parameter to true and the nested_refresh_mode parameter to inconsistent.

    CALL DBMS_MVIEW.REFRESH(
        'mv1',
        nested=> true,
        nested_refresh_mode => 'inconsistent');

• Cascading consistent refresh:

  Specify the mv_name parameter, set the nested parameter to true, and set the nested_refresh_mode parameter to consistent.

  CALL DBMS_MVIEW.REFRESH(
      'mv1',
      nested=> true,
      nested_refresh_mode => 'consistent');

• The following examples result in errors:

  • Set the nested parameter to false and specify the nested_refresh_mode parameter.

    CALL DBMS_MVIEW.REFRESH(
        'mv1',
        nested=> false,
        nested_refresh_mode => 'xxxx');

  • Do not specify the nested parameter and specify the nested_refresh_mode parameter.

    CALL DBMS_MVIEW.REFRESH('mv1', nested_refresh_mode => 'xxxx');

  • Set the nested parameter to true and set the nested_refresh_mode parameter to an invalid string.

    CALL DBMS_MVIEW.REFRESH(
        'mv1',
        nested=> true,
        nested_refresh_mode => 'invalid string');