Hi,
I have not checked the actual queries, but EXPLAIN in old versions of
MySQL did not give sometimes accurate results (specially related to
subqueries). This is an old but illustrative example of it:
https://www.percona.com/blog/2011/10/13/when-explain-estimates-can-go-wrong/
Sometimes running A
Hi all,
The execution plan for this query [1] indicates that it will be entirely
based on existing indexes. Yet in practice, the query takes a long time to
run. Why is that?
Also, interestingly, the execution plan for this modified version [2] is
identical, but it runs almost instantaneously.
La
