DBA_HIST_ACTIVE_SESS_HISTORY displays the history of the contents of the in-memory active session history of recent system activity. This view contains snapshots of V$ACTIVE_SESSION_HISTORY. See "V$ACTIVE_SESSION_HISTORY" for further interpretation details for many of these columns (except SNAP_ID, DBID, and INSTANCE_NUMBER).
| Column | Datatype | NULL | Description |
|---|---|---|---|
SNAP_ID |
NUMBER |
Unique snapshot ID | |
DBID |
NUMBER |
Database ID for the snapshot | |
INSTANCE_NUMBER |
NUMBER |
Instance number for the snapshot | |
SAMPLE_ID |
NUMBER |
ID of the sample | |
SAMPLE_TIME |
TIMESTAMP(3) |
Time of the sample | |
SESSION_ID |
NUMBER |
Session identifier | |
SESSION_SERIAL# |
NUMBER |
Session serial number (used to uniquely identify a session's objects) | |
USER_ID |
NUMBER |
Oracle user identifier | |
SQL_ID |
VARCHAR2(13) |
SQL identifier of the SQL statement that is currently being executed | |
SQL_CHILD_NUMBER |
NUMBER |
Child number of the SQL statement that is currently being executed | |
SQL_PLAN_HASH_VALUE |
NUMBER |
Numerical representation of the SQL plan for the cursor | |
FORCE_MATCHING_SIGNATURE |
NUMBER |
The signature used when the CURSOR_SHARING parameter is set to FORCE |
|
SQL_OPCODE |
NUMBER |
Indicates what phase of operation the SQL statement is in | |
SERVICE_HASH |
NUMBER |
Hash that identifies the Service | |
SESSION_TYPE |
VARCHAR2(10) |
Session type:
|
|
SESSION_STATE |
VARCHAR2(7) |
Session state:
|
|
QC_SESSION_ID |
NUMBER |
Query coordinator session ID | |
QC_INSTANCE_ID |
NUMBER |
Query coordinator instance ID | |
BLOCKING_SESSION |
NUMBER |
Session identifier of the blocking session. Populated only when the session was waiting for enqueues or a "buffer busy" wait. Maps to V$SESSION.BLOCKING_SESSION. |
|
BLOCKING_SESSION_STATUS |
VARCHAR2(11) |
Status of the blocking session:
|
|
BLOCKING_SESSION_SERIAL# |
NUMBER |
Serial number of the blocking session | |
EVENT |
VARCHAR2(64) |
If SESSION_STATE = WAITING, then the event for which the session was waiting at the time of sampling.
If |
|
EVENT_ID |
NUMBER |
Identifier of the resource or event for which the session is waiting or for which the session last waited | |
SEQ# |
NUMBER |
Sequence number that uniquely identifies the wait (incremented for each wait) | |
P1TEXT |
VARCHAR2(64) |
Text of first additional parameter | |
P1 |
NUMBER |
First additional parameter | |
P2TEXT |
VARCHAR2(64) |
Text of second additional parameter | |
P2 |
NUMBER |
Second additional parameter | |
P3TEXT |
VARCHAR2(64) |
Text of third additional parameter | |
P3 |
NUMBER |
Third additional parameter | |
WAIT_CLASS |
VARCHAR2(64) |
Wait class name of the event for which the session was waiting at the time of sampling. Interpretation is similar to that of the EVENT column. Maps to V$SESSION.WAIT_CLASS. |
|
WAIT_CLASS_ID |
NUMBER |
Wait class identifier of the event for which the session was waiting at the time of sampling. Interpretation is similar to that of the EVENT column. Maps to V$SESSION.WAIT_CLASS_ID. |
|
WAIT_TIME |
NUMBER |
Total wait time for the event for which the session last waited (0 if currently waiting) |
|
TIME_WAITED |
NUMBER |
Time that the current session actually spent waiting for the event. This column is set for waits that were in progress at the time the sample was taken. | |
XID |
RAW(8) |
Transaction ID that the session was working on at the time of sampling. V$SESSION does not contain this information. |
|
CURRENT_OBJ# |
NUMBER |
Object ID of the object that the session is currently referencing. This information is only available if the session was waiting for Application, Cluster, Concurrency, and User I/O wait events. Maps to V$SESSION.ROW_WAIT_OBJ#. |
|
CURRENT_FILE# |
NUMBER |
File number of the file containing the block that the session is currently referencing. This information is only available if the session was waiting for Cluster, Concurrency, and User I/O wait events. Maps to V$SESSION.ROW_WAIT_FILE#. |
|
CURRENT_BLOCK# |
NUMBER |
ID of the block that the session is currently referencing | |
PROGRAM |
VARCHAR2(48) |
Name of the operating system program | |
MODULE |
VARCHAR2(48) |
Name of the currently executing module as set by the DBMS_APPLICATION_INFO.SET_MODULE procedure |
|
ACTION |
VARCHAR2(32) |
Name of the currently executing action as set by the DBMS_APPLICATION_INFO.SET_ACTION procedure |
|
CLIENT_ID |
VARCHAR2(64) |
Client identifier of the session |