Re: Simple JOIN is extremely slow.

[Jørgen Løland]

Hi Rick,

>> # Rick: These are frustrating
>> # Jorgen: Handler_read session status indicates that only one record is read
>> in both cases. Maybe a more advanced test case is needed.
> I left out a key prerequisite: There are a million rows with a=2. I believe it
> starts at the beginning of a=2, scans to the end, then backs up to find the
> one row.

In our case we have 8 rows with a=2 and only the one with greatest b value is read so at least in our simple example it works fine. I'll just take your word for the millions-of-rows case :-)

Hope this helps,
Jørgen Løland
Software Engineer, MySQL, Oracle
jorgenloland.blogspot.com