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Oracle® Database Reference
11g Release 2 (11.2)

E40402-12
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V$ACTIVE_SESSION_HISTORY

V$ACTIVE_SESSION_HISTORY displays sampled session activity in the database. It contains snapshots of active database sessions taken once a second. A database session is considered active if it was on the CPU or was waiting for an event that didn't belong to the Idle wait class. Refer to the V$EVENT_NAME view for more information on wait classes.

This view contains one row for each active session per sample and returns the latest session sample rows first. A majority of the columns describing the session in the active session history are present in the V$SESSION view.

Column Datatype Description
SAMPLE_ID NUMBER ID of the sample
SAMPLE_TIME TIMESTAMP(3) Time at which the sample was taken
IS_AWR_SAMPLE VARCHAR2(1) Indicates whether this sample has been flushed or will be flushed to the Automatic Workload Repository (DBA_HIST_ACTIVE_SESS_HISTORY) (Y) or not (N)
SESSION_ID NUMBER Session identifier; maps to V$SESSION.SID
SESSION_SERIAL# NUMBER Session serial number (used to uniquely identify a session's objects); maps to V$SESSION.SERIAL#
SESSION_TYPE VARCHAR2(10) Session type:
  • FOREGROUND

  • BACKGROUND

FLAGS NUMBER Reserved for future use
USER_ID NUMBER Oracle user identifier; maps to V$SESSION.USER#
SQL_ID VARCHAR2(13) SQL identifier of the SQL statement that the session was executing at the time of sampling
IS_SQLID_CURRENT VARCHAR2(1) Indicates whether the SQL identifier in the SQL_ID column is being executed (Y) or not (N)
SQL_CHILD_NUMBER NUMBER Child number of the SQL statement that the session was executing at the time of sampling
SQL_OPCODE NUMBER Indicates what phase of operation the SQL statement was in; maps to V$SESSION.COMMAND

See Also: "V$SESSION" for information on interpreting this column

SQL_OPNAME VARCHAR2(64) SQL command name
FORCE_MATCHING_SIGNATURE NUMBER Signature used when the CURSOR_SHARING parameter is set to FORCE
TOP_LEVEL_SQL_ID VARCHAR2(13) SQL identifier of the top level SQL statement
TOP_LEVEL_SQL_OPCODE NUMBER Indicates what phase of operation the top level SQL statement was in
SQL_PLAN_HASH_VALUE NUMBER Numerical representation of the SQL plan for the cursor. This information might not be available for all session samples. V$SESSION does not contain this information.
SQL_PLAN_LINE_ID NUMBER SQL plan line ID
SQL_PLAN_OPERATION VARCHAR2(30) Plan operation name
SQL_PLAN_OPTIONS VARCHAR2(30) Plan operation options
SQL_EXEC_ID NUMBER SQL execution identifier
SQL_EXEC_START DATE Time when the execution of the SQL started
PLSQL_ENTRY_OBJECT_ID NUMBER Object ID of the top-most PL/SQL subprogram on the stack; NULL if there is no PL/SQL subprogram on the stack. Maps to DBA_OBJECTS.OBJECT_ID.
PLSQL_ENTRY_SUBPROGRAM_ID NUMBER Subprogram ID of the top-most PL/SQL subprogram on the stack. Maps to DBA_OBJECTS.DATA_OBJECT_ID.
PLSQL_OBJECT_ID NUMBER Object ID of the currently executing PL/SQL subprogram. Maps to DBA_OBJECTS.OBJECT_ID.
PLSQL_SUBPROGRAM_ID NUMBER Subprogram ID of the currently executing PL/SQL object; NULL if executing SQL. Maps to DBA_OBJECTS.DATA_OBJECT_ID.
QC_INSTANCE_ID NUMBER Query coordinator instance ID. This information is only available if the sampled session is a parallel query slave. For all other sessions, the value is 0.
QC_SESSION_ID NUMBER Query coordinator session ID. This information is only available if the sampled session is a parallel query slave. For all other sessions, the value is 0.
QC_SESSION_SERIAL# NUMBER Query coordinator session serial number. This information is only available if the sampled session is a parallel query slave. For all other sessions, the value is 0.
PX_FLAGSFoot 1  NUMBER Reserved for internal use
EVENT VARCHAR2(64) If SESSION_STATE = WAITING, then the event for which the session was waiting for at the time of sampling.

If SESSION_STATE = ON CPU, then this column is NULL.

See Also: Appendix C, "Oracle Wait Events"

EVENT_ID NUMBER Identifier of the resource or event for which the session is waiting or for which the session last waited. Interpretation is similar to that of the EVENT column.
EVENT# NUMBER Number of the resource or event for which the session is waiting or for which the session last waited. Interpretation is similar to that of the EVENT column.
SEQ# NUMBER Sequence number that uniquely identifies the wait (incremented for each wait)
P1TEXT VARCHAR2(64) Text of the first additional parameter
P1 NUMBER First additional parameter
P2TEXT VARCHAR2(64) Text of the second additional parameter
P2 NUMBER Second additional parameter
P3TEXT VARCHAR2(64) Text of the 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 if the session was on the CPU when sampled; 0 if the session was waiting at the time of sampling

Note: Whether or not WAIT_TIME = 0 is what is useful to find the SESSION_STATE at the time of sampling, rather than the actual value of WAIT_TIME itself. Maps to V$SESSION.WAIT_TIME.

SESSION_STATE VARCHAR2(7) Session state:
  • WAITING

  • ON CPU

TIME_WAITED NUMBER If SESSION_STATE = WAITING, then the time that the session actually spent waiting for that event (in microseconds). This column is set for waits that were in progress at the time the sample was taken.

If a wait event lasted for more than a second and was caught waiting in more than one session sample row, then the actual time spent waiting for that wait event will be populated in the last of those session sample rows. At any given time, this information will not be available for the latest session sample.

BLOCKING_SESSION_STATUS VARCHAR2(11) Status of the blocking session:
  • VALID

  • NO HOLDER

  • GLOBAL

  • NOT IN WAIT

  • UNKNOWN

BLOCKING_SESSION NUMBER Session identifier of the blocking session. Populated only if the blocker is on the same instance and the session was waiting for enqueues or a "buffer busy" wait. Maps to V$SESSION.BLOCKING_SESSION.
BLOCKING_SESSION_SERIAL# NUMBER Serial number of the blocking session
BLOCKING_INST_ID NUMBER Instance number of the blocker shown in BLOCKING_SESSION
BLOCKING_HANGCHAIN_INFO VARCHAR2(1) Indicates whether the information about BLOCKING_SESSION comes from the hang chain (Y) or not (N)
CURRENT_OBJ# NUMBER Object ID of the object that the session is referencing. This information is only available if the session was waiting for application, cluster, concurrency, and user I/O wait events. Maps to V$SESSION.ROW_WAIT_OBJ#.
CURRENT_FILE# NUMBER File number of the file containing the block that the session is referencing. This information is only available if the session was waiting for cluster, concurrency, and user I/O wait events. Maps to V$SESSION.ROW_WAIT_FILE#.
CURRENT_BLOCK# NUMBER ID of the block that the session is referencing. This information is only available if the session was waiting for cluster, concurrency, and user I/O wait events. Maps to V$SESSION.ROW_WAIT_BLOCK#.
CURRENT_ROW# NUMBER Row identifier that the session is referencing. This information is only available if the session was waiting for cluster, concurrency, and user I/O wait events. Maps to V$SESSION.ROW_WAIT_ROW#.
TOP_LEVEL_CALL# NUMBER Oracle top level call number
TOP_LEVEL_CALL_NAME VARCHAR2(64) Oracle top level call name
CONSUMER_GROUP_ID NUMBER Consumer group ID
XID RAW(8) Transaction ID that the session was working on at the time of sampling. V$SESSION does not contain this information.
REMOTE_INSTANCE# NUMBER Remote instance identifier that will serve the block that this session is waiting for. This information is only available if the session was waiting for cluster events.
TIME_MODEL NUMBER Time model information
IN_CONNECTION_MGMT VARCHAR2(1) Indicates whether the session was doing connection management at the time of sampling (Y) or not (N)
IN_PARSE VARCHAR2(1) Indicates whether the session was parsing at the time of sampling (Y) or not (N)
IN_HARD_PARSE VARCHAR2(1) Indicates whether the session was hard parsing at the time of sampling (Y) or not (N)
IN_SQL_EXECUTION VARCHAR2(1) Indicates whether the session was executing SQL statements at the time of sampling (Y) or not (N)
IN_PLSQL_EXECUTION VARCHAR2(1) Indicates whether the session was executing PL/SQL at the time of sampling (Y) or not (N)
IN_PLSQL_RPC VARCHAR2(1) Indicates whether the session was executing inbound PL/SQL RPC calls at the time of sampling (Y) or not (N)
IN_PLSQL_COMPILATION VARCHAR2(1) Indicates whether the session was compiling PL/SQL at the time of sampling (Y) or not (N)
IN_JAVA_EXECUTION VARCHAR2(1) Indicates whether the session was executing Java at the time of sampling (Y) or not (N)
IN_BIND VARCHAR2(1) Indicates whether the session was doing bind operations at the time of sampling (Y) or not (N)
IN_CURSOR_CLOSE VARCHAR2(1) Indicates whether the session was closing a cursor at the time of sampling (Y) or not (N)
IN_SEQUENCE_LOAD VARCHAR2(1) Indicates whether the session is loading in sequence (in sequence load code) (Y) or not (N)
CAPTURE_OVERHEAD VARCHAR2(1) Indicates whether the session is executing capture code (Y) or not (N)
REPLAY_OVERHEAD VARCHAR2(1) Indicates whether the session is executing replay code (Y) or not (N)
IS_CAPTURED VARCHAR2(1) Indicates whether the session is being captured (Y) or not (N)
IS_REPLAYED VARCHAR2(1) Indicates whether the session is being replayed (Y) or not (N)
SERVICE_HASH NUMBER Hash that identifies the Service; maps to V$ACTIVE_SERVICES.NAME_HASH
PROGRAM VARCHAR2(48) Name of the operating system program
MODULEFoot 2  VARCHAR2(48) Name of the executing module when sampled, as set by the DBMS_APPLICATION_INFO.SET_MODULE procedure
ACTIONFootref 2 VARCHAR2(32) Name of the executing module when sampled, as set by the DBMS_APPLICATION_INFO.SET_ACTION procedure
CLIENT_ID VARCHAR2(64) Client identifier of the session; maps to V$SESSION.CLIENT_IDENTIFIER
MACHINE VARCHAR2(64) Client's operating system machine name
PORT NUMBER Client port number
ECID VARCHAR2(64) Execution context identifier (sent by Application Server)
DBREPLAY_FILE_IDFootref 1 NUMBER If the session is being captured or replayed, then DBREPLAY_FILE_ID is the file ID for the workload capture or workload replay; otherwise it is NULL.
DBREPLAY_CALL_COUNTERFootref 1 NUMBER If the session is being captured or replayed, then DBREPLAY_CALL_COUNTER is the call counter of the user call that is being captured or replayed; otherwise it is NULL.
TM_DELTA_TIME NUMBER Time interval (in microseconds) over which TM_DELTA_CPU_TIME and TM_DELTA_DB_TIME are accumulated
TM_DELTA_CPU_TIME NUMBER Amount of time this session spent on CPU over the last TM_DELTA_TIME microseconds
TM_DELTA_DB_TIME NUMBER Amount of time spent by this session in database calls over the last TM_DELTA_TIME microseconds
DELTA_TIME NUMBER Time interval (in microseconds) since the last time this session was sampled or created, over which the next five statistics are accumulated
DELTA_READ_IO_REQUESTS NUMBER Number of read I/O requests made by this session over the last DELTA_TIME microseconds
DELTA_WRITE_IO_REQUESTS NUMBER Number of write I/O requests made by this session over the last DELTA_TIME microseconds
DELTA_READ_IO_BYTES NUMBER Number of I/O bytes read by this session over the last DELTA_TIME microseconds
DELTA_WRITE_IO_BYTES NUMBER Number of I/O bytes written by this session over the last DELTA_TIME microseconds
DELTA_INTERCONNECT_IO_BYTES NUMBER Number of I/O bytes sent over the I/O interconnect over the last DELTA_TIME microseconds
PGA_ALLOCATED NUMBER Amount of PGA memory (in bytes) consumed by this session at the time this sample was taken
TEMP_SPACE_ALLOCATED NUMBER Amount of TEMP memory (in bytes) consumed by this session at the time this sample was taken

Footnote 1 This column is available starting with Oracle Database 11g Release 2 (11.2.0.2).

Footnote 2 The datatype of this column is VARCHAR2(64) starting with Oracle Database 11g Release 2 (11.2.0.2).