SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 2) ExpressionList (children 3) Function stddevPop (children 1) ExpressionList (children 1) Function toFloat64 (children 1) ExpressionList (children 1) Identifier a Function stddevPop (children 1) ExpressionList (children 1) Function toFloat64 (children 1) ExpressionList (children 1) Identifier b Function stddevPop (children 1) ExpressionList (children 1) Function toFloat64 (children 1) ExpressionList (children 1) Identifier c TablesInSelectQuery (children 1) TablesInSelectQueryElement (children 1) TableExpression (children 1) TableIdentifier decimal