diff --git a/docs/en/engines/table-engines/mergetree-family/replication.md b/docs/en/engines/table-engines/mergetree-family/replication.md index 625869a3cb8f44fdf34aefcb4769883229422da5..4758ff321e8e7c15c75cc7f3806e14cfc8b94a0a 100644 --- a/docs/en/engines/table-engines/mergetree-family/replication.md +++ b/docs/en/engines/table-engines/mergetree-family/replication.md @@ -113,6 +113,8 @@ You can have any number of replicas of the same data. Yandex.Metrica uses double The system monitors data synchronicity on replicas and is able to recover after a failure. Failover is automatic (for small differences in data) or semi-automatic (when data differs too much, which may indicate a configuration error). +You can use a special logic for performing merges (for more information, see the documentation for [execute_merges_on_single_replica_time_threshold](../../../operations/settings/settings.md#execute-merges-on-single-replica-time-threshold) setting). + ## Creating Replicated Tables {#creating-replicated-tables} The `Replicated` prefix is added to the table engine name. For example:`ReplicatedMergeTree`. diff --git a/docs/en/operations/settings/settings.md b/docs/en/operations/settings/settings.md index c5e44d4c464b2ed02b479881e64e5b09b5576f30..3b2c9a679998ffc76a6846fc3a77a4f4e6acff2c 100644 --- a/docs/en/operations/settings/settings.md +++ b/docs/en/operations/settings/settings.md @@ -2410,7 +2410,6 @@ Result: {"number":"1"} {"number":"2"} ``` - ======= ## allow_nullable_key {#allow-nullable-key} @@ -2423,4 +2422,19 @@ Possible values: Default value: `0`. +## execute_merges_on_single_replica_time_threshold {#execute-merges-on-single-replica-time-threshold} + +Enables special logic to perform merges on replicas. + +Possible values: + +- Positive integer (in seconds). +- 0 — Special merge logic is not executed. + +Default value: `0`. + +**Special logic to perform merges** + +Selects one replica to perform the merge on. Sets the time threshold from the start of the merge. Other replicas wait for the merge to finish, then download the result. If the time threshold passes and the selected replica does not perform merges, then the merge is performed manually. + [Original article](https://clickhouse.tech/docs/en/operations/settings/settings/)