OpsMgr uses two Microsoft SQL Server databases for all collected data. Both databases are automatically maintained through OpsMgr-specific scheduled maintenance tasks.
The operations database stores all the monitoring rules and is imported by management packs and operational data collected from each monitored system. Data in this database is retained for seven days by default. Data retention for the operations database is lower than the reporting database to improve efficiency of the environment.
The operations database must be installed as a separate component from OpsMgr. However, it can physically reside on the same server, if needed.
The reporting database stores data for long-term trend ...