lightweight_* session settings

These settings are available in system.settings and are autogenerated from source.

lightweight_delete_mode

A mode of internal update query that is executed as a part of lightweight delete. Possible values:

alter_update - run ALTER UPDATE query that creates a heavyweight mutation.
lightweight_update - run lightweight update if possible, run ALTER UPDATE otherwise.
lightweight_update_force - run lightweight update if possible, throw otherwise.

The same as mutations_sync, but controls only execution of lightweight deletes. Possible values:

Value	Description
`0`	Mutations execute asynchronously.
`1`	The query waits for the lightweight deletes to complete on the current server.
`2`	The query waits for the lightweight deletes to complete on all replicas (if they exist).
`3`	The query waits only for active replicas. Supported only for `SharedMergeTree`. For `ReplicatedMergeTree` it behaves the same as `mutations_sync = 2`.

See Also

Cloud default value: 1.