Logging to a database from a Cisco router is not a direct process. Instead, the standard process is to use a syslog server to capture the data and store it into a database. For example, we used Kiwi Syslog server to capture our Cisco device data and store it into a SQL server. Kiwi will store data into any ODBC database, which would include Oracle. Here is a link to Kiwi:
http://www.kiwisyslog.com/kiwi-syslog-server-overview/[
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Which syslog server you used would be up to you but that is how you would get the data into the database.