Mixed data type from mySQL 4/5 driver in CF9

I am not sure is this a feature or bug.

var query1 = queryNew("RenewalFrequency","varchar");

var query2 = queryNew("RenewalFrequency","varchar");

var query3 = queryNew("RenewalFrequency","varchar");

<cfquery datasource="test" name="query1"> SELECT Concat(1,' ','Year') AS RenewalFrequency FROM Skill </cfquery>

<cfquery datasource="test" name="query2"> SELECT Concat('1',' ','Year') AS RenewalFrequency FROM Skill </cfquery>

<cfquery datasource="test" name="query3"> SELECT if(ID > 10, Concat(1,' ','Year'), Concat('1',' ','Year')) AS RenewalFrequency

FROM Skill</cfquery>

When i use cfdump to dump all 3 queries.

query1 will display as data type = binary

query2 will display as data type = string

query3 will display mixed data type "string" and "binary"

I ran same 3 queries on CF8, all 3 return data type as "string".

I though you can't have mixed data type within the same column.