SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 4) ExpressionList (children 1) Function count (children 1) ExpressionList TablesInSelectQuery (children 1) TablesInSelectQueryElement (children 1) TableExpression (children 1) TableIdentifier tab Function equals (children 1) ExpressionList (children 2) Identifier str_fixed Function toFixedString (children 1) ExpressionList (children 2) Literal \'foo\' Literal UInt64_3 Set