CreateQuery merge (children 3) Identifier merge Columns definition (children 1) ExpressionList (children 2) ColumnDeclaration d (children 2) DataType Date Literal \'2000-01-01\' ColumnDeclaration x (children 1) DataType UInt64 Storage definition (children 1) Function MergeTree (children 1) ExpressionList (children 3) Identifier d Identifier x Literal UInt64_5