As with logging of any sort, it is important to maintain the resulting data. Logfiles are typically logrotated and eventually deleted. The same should be applied to data in the logging table.

Besides that, an administrator of an OLAT instance needs to have an idea of how much traffic is expected and whether this traffic can be handled by the chosen infrastructure.

For smaller installations it should be no worries to have the logging table in the main database. With bigger installations though, it is recommended to think about master/slave setups with e.g. a BLACKHOLE engine at the master side and MERGE tables with COMPRESS tables at the slave side (in MySQL). This document contains a drawing of how this can be achieved.