Re: Optimizer Decisions change with Storage Engine [MyISAM, InnoDB]

[Drei Bit]

Hi,

I do not use the idx in the select list!

Again my query is:

select * 
from A 
	join (select id from b where dummy like 'xyz%') x on x.id = a.id

As you can see the subquery named x

select id from b where dummy like 'xyz%'

in the from part of the complete query is not reading the IDX field at all (it doesn't matter if you use table B or C here). So no need to look it up.
the select * in the beginning is thus only giving back all columns of Table A which do have a join Partner in the subquery x. So no IDX involved at all (this is true for both queries).

greetings
3bit