This is a document for PGroonga 1.X. See PGroonga 2.x document when you're using recent PGroonga.
pgroonga.match_escalation_threshold parameter controls when match escalation is occurred.
Match escalation is auto loose search. If the number of matched records is equal or less than the threshold specified by
pgroonga.match_escalation_threshold parameter, loose search is done automatically. It's match escalation.
The default threshold is
0. It means that no records are matched, loose search is done automatically.
You can disable match escalation by specifying
Normally, you don't need to change this parameter. Auto loose search is useful for users.
SET pgroonga.match_escalation_threshold = threshold;
pgroonga.match_escalation_threshold = threshold
threshold is a number value.
Here is an example to disable match escalation:
SET pgroonga.match_escalation_threshold = -1;