174 Oracle Database 11g DBA Handbook
The values in this view are typically maintained via the OEM interface; in addition, the Oracle
10g DBMS_SERVER_ALERT built-in PL/SQL package can set and get the threshold values with
the SET_THRESHOLD and GET_THRESHOLD procedures, respectively. To read alert messages
in the alert queue, you can use the DBMS_AQ and DBMS_AQADM packages, or OEM can be
configured to send a pager or e-mail message when the thresholds have been exceeded.
For a default installation of Oracle Database 10g and Oracle Database 11g, a number of
thresholds are configured, including the following:
At least one user session is blocked every minute for three consecutive minutes.
Any segments are not able to extend for any reason.
The total number of concurrent processes comes within 80 percent of the PROCESSES
initialization parameter value.
More than two invalid objects exist for any individual database user.
The total number of concurrent user sessions comes within 80 percent of the SESSIONS
initialization parameter value.
There are more than 1200 concurrent open cursors.
There are more than 100 logons per second.
A tablespace is more than 85 percent full (warning) or more than 97 percent full (critical).
User logon time is greater than 1000 milliseconds (1 second).
DBA_OUTSTANDING_ALERTS
The Oracle 10g view DBA_OUTSTANDING_ALERTS contains one row for each active alert in the
database, until the alert is cleared or reset.
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