Update dml-set-cluster-key.md
@@ -6,6 +6,8 @@ description:
Sets a cluster key when creating a table.
+Cluster key is intended to improve query performance by physically clustering data together. For example, when you set a column as your cluster key for a table, the table data will be physically sorted by the column you set. This will maximize the query performance if your most queries are filtered by the column.
+
See also:
* [ALTER CLUSTER KEY](./dml-alter-cluster-key.md)
