As Adobe AEM mentioned :
To enable logging, you need to enable DEBUG level logs for the categories pertaining to Oak indexing and queries. These categories are:
- org.apache.jackrabbit.oak.plugins.index
- org.apache.jackrabbit.oak.query
- com.day.cq.search
The com.day.cq.search category is only applicable if you are using the AEM provided QueryBuilder utility.
You can enable logging by following pointing your browser to http://localhost:4502/system/console/slinglog
AEM Treasury 