MaxCompute provides the lifecycle management function to facilitate the release of storage space and simplify data reclamation.

You can specify the lifecycle when you create a table. The lifecycle can only be set for a table rather than a partition. For more information, see Table operations.
  • In MaxCompute, once data in a table is modified, the LastDataModifiedTime value is updated. Therefore, MaxCompute determines whether to reclaim this table based on the LastDataModifiedTime value and lifecycle.
  • For a non-partitioned table, if the data remains unchanged for days after the last data modification, MaxCompute automatically executes a statement such as DROP TABLE to reclaim the table.
  • For a partitioned table, MaxCompute determines whether to reclaim a partition based on its LastDataModifiedTime value.
  • Unlike non-partitioned tables, a partitioned table is not deleted after the last partition is reclaimed.
  • Instead of deleting the lifecycle configured for a non-partitioned table, you can only modify the lifecycle setting. The lifecycle configured for a specific partition in a partitioned table can be deleted.

Change the lifecycle configured for a table

Syntax 
ALTER TABLE table_name SET lifecycle days;

Description: used to change the lifecycle configured for a table.

Parameters
  • table_name: the name of the table whose lifecycle setting you want to modify.
  • days: the lifecycle duration, which must be a positive integer in days.
Example 
-- Create a table named test_lifecycle with a lifecycle of 100 days.
CREATE TABLE test_lifecycle(key string) lifecycle 100;
-- Change the lifecycle of test_lifecycle to 50 days.
ALTER TABLE test_lifecycle SET lifecycle 50;

Disable or restore the lifecycle feature

Syntax 
ALTER TABLE table_name [partition_spec] ENABLE|DISABLE LIFECYCLE;

Description: used to enable or disable the lifecycle feature for a table or a specific partition in a table.

Parameters
  • table_name: the name of the table.
  • partition_spec: the name of the partition.
  • DISABLE LIFECYCLE: used to disable the lifecycle feature for the table or partition.
    • It prevents the reclamation of a table and its partitions based on the lifecycle feature. This parameter has a higher priority than partition_spec enable lifecycle.
    • After the lifecycle feature of a table is disabled, the table lifecycle setting and the ENABLE and DISABLE tags of partitions in the table are retained.
    • After the lifecycle feature of a table is disabled, you can still modify the lifecycle settings of the table and its partitions.
  • ENABLE LIFECYCLE: used to enable the lifecycle feature for the table or partition.
    • After the lifecycle feature is enabled again, a table and its partitions can be reclaimed based on the lifecycle feature. By default, the lifecycle settings of the current table and its partitions are used.
    • Before you enable the lifecycle feature for a table, you can modify the lifecycle settings of the table and its partitions as needed. This prevents data from being mistakenly reclaimed due to the use of previous settings.
Example 
-- Disable the lifecycle feature for table trans.
ALTER TABLE trans  DISABLE LIFECYCLE;
-- Disable the lifecycle feature for the dt='20141111' partition in table trans.
ALTER TABLE trans PARTITION(dt='20141111') DISABLE LIFECYCLE;