Merge pull request #20306 from bharatnc/ncb/docs-rename-column

Document ALTER RENAME Column

docs/en/sql-reference/statements/alter/column.md

@@ -25,6 +25,7 @@ The following actions are supported:
 -   [COMMENT COLUMN](#alter_comment-column) — Adds a text comment to the column.
 -   [MODIFY COLUMN](#alter_modify-column) — Changes column’s type, default expression and TTL.
 -   [MODIFY COLUMN REMOVE](#modify-remove) — Removes one of the column properties.
+-   [RENAME COLUMN](#alter_rename-column) — Renames an existing column.
 
 These actions are described in detail below.
 
@@ -183,6 +184,22 @@ ALTER TABLE table_with_ttl MODIFY COLUMN column_ttl REMOVE TTL;
 
 - [REMOVE TTL](ttl.md).
 
+## RENAME COLUMN {#alter_rename-column}
+
+Renames an existing column.
+
+Syntax:
+
+```sql
+ALTER TABLE table_name RENAME COLUMN column_name TO new_column_name;
+```
+
+**Example**
+
+```sql
+ALTER TABLE table_with_ttl RENAME COLUMN column_ttl TO column_ttl_new;
+```
+
 ## Limitations {#alter-query-limitations}
 
 The `ALTER` query lets you create and delete separate elements (columns) in nested data structures, but not whole nested data structures. To add a nested data structure, you can add columns with a name like `name.nested_name` and the type `Array(T)`. A nested data structure is equivalent to multiple array columns with a name that has the same prefix before the dot.