Options to set search operator to AND/OR

Customer addressed this:

We'd like to use - the very common - default logical AND operator for searches of our content in Confluence.
Can't find a config option in Confluence to switch the default Lucene OR operator to AND.
Is this not configurable ?

And it is related with https://jira.atlassian.com/browse/CONF-30974

Note:
The default search operator is OR although in 2006 we made AND available.

This is not configurable though and it is an intended change to the searching algorithm. Due to the way that the phrase ranking works, it shouldn't be a problem though, because it should include all of the "AND" matches already, and they should be ranked the highest. What this means is the results will read like:

1. All of the "AND" results appear first
2. Results with less keyword matches will appear below, in order of how many keywords match, highest to lowest

Customer would like to have the option of AND/OR search.