The documentation for function ClassDB.importConnectionLog has not been updated to describe the structure and content of the table it returns.
The function was enhanced in M3 to return a table, but the docs have not been updated. It presently just asks user to run the following query:
SELECT * FROM ClassDB.importConnectionLog()
PS: The docs used to ask users to run SELECT ClassDB.importConnectionLog(), but I just now edited it to match the M3 enhancement so the docs are a bit more useful than they were.