Re: Patch for bug#42208

[Ann W. Harrison]

Kevin Lewis wrote:
> 
> Well, here is the MySQL (read MyISAM) implemetation;
> 
> 1) BINARY fixed length fields are always padded out to the fixed length. 
>  Thus for a BINARY(5) column; 0x00, 0x0000, 0x000000 and 0x00000000 are 
> all equal because they are all stored and sorted as 0x0000000000.
> 
> 2) VARBINARY fields must take into account the actual length.
> Thus for a VARBINARY column; 0x00, 0x0000, 0x000000 and 0x00000000 are 
> all different and sorted by length.
> 

And if you compare a binary with a varbinary?  Are constants fixed
or varying?

I realize that the MyISAM implementation is definitive by definition,
but I wish it had been better thought out.  At least with strings,
'a' = 'a', regardless of whether they're stored as char(20) or
varchar(20).

Vlad's suggestion for a reimplementation of multi-segment
keys with suffix compression solves the problem and lets
us work like MyISAM.  In spite of that, it seems like a good
idea.

Cheers,

Ann