v.25.4New Feature

Setting parallel_distributed_insert_select makes effect

The setting parallel_distributed_insert_select makes effect for INSERT SELECT into ReplicatedMergeTree (previously it required Distribued tables). #78041 (Igor Nikonov).
The setting parallel_distributed_insert_select now applies to INSERT SELECT operations directly into ReplicatedMergeTree tables, expanding its previous scope beyond just Distributed tables.

Why it matters

This feature enables parallel execution of INSERT SELECT queries on ReplicatedMergeTree tables, improving insert performance and resource utilization by allowing distributed parallel processing without requiring an intermediary Distributed table.

How to use it

To leverage this feature, set the parallel_distributed_insert_select setting to 1 (enabled) before running your INSERT SELECT query targeting a ReplicatedMergeTree table. For example:

SET parallel_distributed_insert_select = 1;
INSERT INTO target_table SELECT * FROM source_table;