We were recently trying to expand the amount of logging data we're keeping in ULS due to some recent issues. Our first stop for research is always the ULSTraceLog tables in the logging database, but we noticed that any event less severe Monitorable is not in the database, but is in the ULS logs on disk.  Is there a setting that controls this, or is the database limited in such a way that these lower severity events are only captured on disk, but not copied in to the logging database?

Hi,

You use SharePoint 2013 Central Administration to configure logs imported into the logging database.

About how to specify the events to be written to the logging database and the frequency that logs are written to the logging database for your reference:

https://technet.microsoft.com/en-us/library/ee748593.aspx

About how to enable what is written into the logging database for your reference:

https://technet.microsoft.com/en-us/library/ee663480.aspx

About how to configure log categories, log levels, and trace (ULS) log path for your reference:

https://technet.microsoft.com/en-us/library/ee748656.aspx

More information about viewing data in the logging database in SharePoint 2013:

https://technet.microsoft.com/en-us/library/jj715694.aspx

Best Regards,

Dean Wang