Dba daily struggle

In Oracle 10.2 and above with ASH is very useful to see the number of sessions active and connected to a database over time: You can use this 2 views to obtain this information: v$sysmetric_history --> This is a sort term view, that contains data of last hour by intervals of minutes dba_hist_sysmetric_summary -->This is a long term view, that contains data of last month by intervals of 1 hour. v$sysmetric_history and dba_hist_sysmetric_summary contains information a lot of different metrics information, so the first thing we need to do is to filter metric type. With this query you can select a list of all metric types: set linesize 190 col METRIC_NAME for a100 select METRIC_ID, METRIC_NAME from v$sysmetric_history group by METRIC_ID, METRIC_NAME ; for example, if you are looking for metrics related with connected sessions to database, you can do: SQL> set linesize 190 col METRIC_NAME for a100 select METRIC_ID, METRIC_NAME from v$sysmetric_history where lo...