The number of use cases for subsearches in the real world might be small, but for those situations where they can be applied, subsearches can be a magic bullet. Let's look at an example and then talk about some rules.
Let's start with these events:
2015-02-10 12:59:59 msgid=704783 [email protected] [email protected] 2015-02-10 12:59:59 msgid=171755 [email protected] [email protected] 2015-02-10 12:59:59 msgid=668955 [email protected] [email protected] 2015-02-10 12:59:59 msgid=001404 [email protected] [email protected] 2015-02-10 12:59:59 msgid=284794 [email protected] [email protected] 2015-02-10 12:59:59 msgid=362127 [email protected] [email protected] 2015-02-10 12:59:59 msgid=571419 [email protected] to=ronnie@g&r.com
From these events, let's find out to whom mary
has sent messages. In these events, we see that the from
and to
values are in different entries. We...