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When we need to add/remove or change LIMIT, INTERVAL, AUTO we have to recreate partitioning from scratch (via data copy). Such operations should be done fast. To remove options like LIMIT or INTERVAL one should write: alter table t1 partition by system_time; The command checks whether it is new or existing SYSTEM_TIME partitioning. And in the case of new it behaves as CREATE would do: adds default number of partitions (2). If SYSTEM_TIME partitioning already existed it just changes its options: removes unspecified ones and adds/changes those specified explicitly. In case when partitions list was supplied it behaves as usual: does full repartitioning. Examples: create or replace table t1 (x int) with system versioning partition by system_time limit 100 partitions 4; # Change LIMIT alter table t1 partition by system_time limit 33; # Remove LIMIT alter table t1 partition by system_time; # This does full repartitioning alter table t1 partition by system_time limit 33 partitions 4; # This does data copy as pruning will require records in correct partitions alter table t1 partition by system_time interval 1 hour starts '2000-01-01 00:00:00'; # But this works fast, LIMIT will apply to DML commands alter table t1 partition by system_time limit 33; To sum up, ALTER for SYSTEM_TIME partitioning does full repartitioning when: - INTERVAL was added or changed; - partition list or partition number was specified; Otherwise it does fast alter table. Cleaned up dead condition in set_up_default_partitions(). Reviewed by: Oleksandr Byelkin <sanja@mariadb.com> Nikita Malyavin <nikitamalyavin@gmail.com>