SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 2) ExpressionList (children 1) Function sum (children 1) ExpressionList (children 1) Identifier DISTINCT TablesInSelectQuery (children 1) TablesInSelectQueryElement (children 1) TableExpression (children 1) Subquery (children 1) SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 1) ExpressionList (children 1) Literal UInt64_1 (alias DISTINCT)