SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 4) ExpressionList (children 1) Asterisk TablesInSelectQuery (children 1) TablesInSelectQueryElement (children 1) TableExpression (children 1) TableIdentifier merge_tree_deduplication Function equals (children 1) ExpressionList (children 2) Identifier part Literal UInt64_33 ExpressionList (children 1) OrderByElement (children 1) Identifier key