Logging resource usage data to database tables incurs costs:
- Writing to the database adds to the system I/O load. On a heavily loaded system, this could affect the production workload throughput.
- The rows written to the database take up space. If this space is never reclaimed, it will eventually grow to consume all available space in user DBC.
- In an extremely loaded system, it is possible that the RSS can fall behind in writing data to the database. Although it caches such data and eventually catches up if given a chance, the RSS is forced to start discarding rows if the system load persists and its cache capacity is exceeded.