Re: MySql 5.7.3 m13 deadly slow - config issue?

[Øystein Grøvlen]

Hi Adam,

I would have expected that your query would use subquery materialization (described in this blog: http://guilhembichot.blogspot.co.uk/2012/04/faster-subqueries-with-materialization.html)

From the query plan it seems that you are not doing index look-ups into the inner table. Are you sure the number columns have the same type/character set/collation?
Could you show the output of "SHOW CREATE TABLE" for the two tables?

In order to fully understand what happens here, it would be great to see the optimizer trace for your query. (See http://dev.mysql.com/doc/internals/en/optimizer-tracing.html for how to get this).

Thanks,

Øystein Grøvlen,
Senior Principal Software Engineer,
MySQL Group, Oracle,
Trondheim, Norway