REFRESH MATERIALIZED VIEW

Description

Manually refresh a specific asynchronous materialized view or partitions within.

CAUTION

You can only manually refresh materialized views that adopt ASYNC or MANUAL refresh strategy. You can check the refresh strategy of an asynchronous materialized view using SHOW MATERIALIZED VIEWS.

Syntax

REFRESH MATERIALIZED VIEW [database.]mv_name
[PARTITION START ("<partition_start_date>") END ("<partition_end_date>")]
[FORCE]
[WITH { SYNC | ASYNC } MODE]

Parameters

ParameterRequiredDescription
mv_nameyesThe name of the materialized view to refresh manually.
PARTITION START () END ()noManually refresh partitions within a certain time interval.
partition_start_datenoThe start date of the partitions to refresh manually.
partition_end_datenoThe end date of the partitions to refresh manually.
FORCEnoIf you specify this parameter, CelerData forcibly refreshes the corresponding materialized view or partitions. If you do not specify this parameter, CelerData automatically judges if the data is updated and refreshes the partition only when needed.
WITH ... MODEnoMake a synchronous or asynchronous call of the refresh task. SYNC indicates making a synchronous call of the refresh task, and CelerData returns the task result only when the task succeeds or fails. ASYNC indicates making an asynchronous call of the refresh task, and CelerData returns success right after the task is submitted, leaving the task to be executed asynchronously in the background. You can check the refresh task status of an asynchronous materialized view by querying the tasks and task_runs metadata tables in CelerData' Information Schema. For more information, see Check the execution status of asynchronous materialized view. Default: ASYNC.

CAUTION

When refreshing materialized views created based on the external catalogs, CelerData refreshes all partitions in the materialized views.

Examples

Example 1: Manually refresh a specific materialized view via an asynchronous call.

REFRESH MATERIALIZED VIEW lo_mv1;

REFRESH MATERIALIZED VIEW lo_mv1 WITH ASYNC MODE;

Example 2: Manually refresh certain partitions of a specific materialized view.

REFRESH MATERIALIZED VIEW lo_mv1 
PARTITION START ("2020-02-01") END ("2020-03-01");

Example 3: Forcibly refresh certain partitions of a specific materialized view.

REFRESH MATERIALIZED VIEW lo_mv1
PARTITION START ("2020-02-01") END ("2020-03-01") FORCE;

Example 4: Manually refresh a materialized view via a synchronous call.

REFRESH MATERIALIZED VIEW lo_mv1 WITH SYNC MODE;