Use MergeTree as Default Table Engine

Why it matters

This feature sets MergeTree as the default engine when creating new tables without specifying an engine. It simplifies table creation by providing a performant and widely-used default storage engine, reducing errors and improving usability for users unfamiliar with engine selection.

How to use it

When creating a table without specifying the engine, ClickHouse will automatically use the MergeTree engine. For example:

CREATE TABLE example_table (
    id UInt32,
    data String
) 
-- No ENGINE specified, so defaults to <code>MergeTree</code>

This removes the need to explicitly specify ENGINE = MergeTree().