Correlation Analysis Reports with AWR and
ASH Views
Remember, the ASH stores the history of a
recent session’s activity in dba_hist_active_sess_history
and this data is designed as a rolling buffer in memory
where earlier
information is overwritten when needed. To do this,
the
dba_hist_active_sess_history view
is needed as it
contains historical block-level contention statistics.
|
COLUMN |
DESCRIPTION |
|
SNAP_ID |
Unique snapshot ID |
|
SAMPLE_TIME |
Time of the sample |
|
SESSION_ID |
Session
identifier |
|
SESSION_SERIAL# |
Session serial number (used to
uniquely identify a session's objects) |
|
USER_ID |
Oracle user identifier |
|
CURRENT_OBJ# |
Object ID of the object that the
session is currently referencing |
|
CURRENT_FILE# |
File number of the file containing
the block that the session is currently referencing |
|
CURRENT_BLOCK# |
ID of the block that the session is
currently referencing |
|
WAIT_TIME |
Total wait time for the event for
which the session last waited (0 if currently waiting) |
|
TIME_WAITED |
Time that the current session
actually spent waiting for the event. This column is set
for waits that were in progress at the time the sample
was taken. |
