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oracle官方文档之V$SESSION

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V$SESSION

V$SESSION
displays session information for each current session.

ColumnDatatypeDescription
SADDR
RAW(4 | 8)
Session address
SID
NUMBER
Session identifier
SERIAL#
NUMBER
Session serial number. Used to uniquely identify a session's objects. Guarantees that session-level commands are applied to the correct session objects if the session ends and another session begins
with the same session ID.
AUDSID
NUMBER
Auditing session ID
PADDR
RAW(4 | 8)
Address of the process that owns the session
USER#
NUMBER
Oracle user identifier
USERNAME
VARCHAR2(30)
Oracle username
COMMAND
NUMBER
Command in progress (last statement parsed).
You can find the command name for any value n returned in this
COMMAND
column by running this SQL query:

SELECT command_name
FROM v$sqlcommand
WHERE command_type = n;

A value of 
0
in this 
COMMAND
column means the command is not recorded in
V$SESSION
.

OWNERID
NUMBER
Identifier of the user who owns the migratable session; the column contents are invalid if the value is
2147483644

For operations using Parallel Slaves, interpret this value as a 4-byte value. The low-order 2 bytes represent the session number and the high-order bytes represent the instance ID of the query coordinator.

TADDR
VARCHAR2(8)
Address of the transaction state object
LOCKWAIT
VARCHAR2(8)
Address of the lock the session is waiting for; NULL if none
STATUS
VARCHAR2(8)
Status of the session:

ACTIVE
- Session currently executing SQL

INACTIVE
- Session which is inactive and either has no configured limits or has not yet exceeded the configured limits

KILLED
- Session marked to be killed

CACHED
- Session temporarily cached for use by Oracle*XA

SNIPED
- An inactive session that has exceeded some configured limits (for example, resource limits specified for the resource manager consumer group or idle_time specified in the user's profile). Such sessions will not be allowed to become
active again.

SERVER
VARCHAR2(9)
Server type:

DEDICATED


SHARED


PSEUDO


POOLED


NONE


SCHEMA#
NUMBER
Schema user identifier
SCHEMANAME
VARCHAR2(30)
Schema user name
OSUSER
VARCHAR2(30)
Operating system client user name
PROCESS
VARCHAR2(24)
Operating system client process ID
MACHINE
VARCHAR2(64)
Operating system machine name
PORT
NUMBER
Client port number
TERMINAL
VARCHAR2(30)
Operating system terminal name
PROGRAM
VARCHAR2(48)
Operating system program name
TYPE
VARCHAR2(10)
Session type
SQL_ADDRESS
RAW(4 | 8)
Used with 
SQL_HASH_VALUE
to identify the SQL statement that is currently being executed
SQL_HASH_VALUE
NUMBER
Used with 
SQL_ADDRESS
to identify the SQL statement that is currently being executed
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_EXEC_START
DATE
Time when the execution of the SQL currently executed by this session started; NULL if
SQL_ID
is NULL
SQL_EXEC_ID
NUMBER
SQL execution identifier; NULL if
SQL_ID
is NULL or if the execution of that SQL has not yet started (see
V$SQL_MONITOR
)
PREV_SQL_ADDR
RAW(4 | 8)
Used with 
PREV_HASH_VALUE
to identify the last SQL statement executed
PREV_HASH_VALUE
NUMBER
Used with 
SQL_HASH_VALUE
to identify the last SQL statement executed
PREV_SQL_ID
VARCHAR2(13)
SQL identifier of the last SQL statement executed
PREV_CHILD_NUMBER
NUMBER
Child number of the last SQL statement executed
PREV_EXEC_START
DATE
SQL execution start of the last executed SQL statement
PREV_EXEC_ID
NUMBER
SQL execution identifier of the last executed SQL statement
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
PLSQL_ENTRY_SUBPROGRAM_ID
NUMBER
Subprogram ID of the top-most PL/SQL subprogram on the stack; NULL if there is no PL/SQL subprogram on the stack
PLSQL_OBJECT_ID
NUMBER
Object ID of the currently executing PL/SQL subprogram; NULL if executing SQL
PLSQL_SUBPROGRAM_ID
NUMBER
Subprogram ID of the currently executing PL/SQL object; NULL if executing SQL
MODULE
Foot 1 
VARCHAR2(48)
Name of the currently executing module as set by calling the
DBMS_APPLICATION_INFO.SET_MODULE
procedure
MODULE_HASH
NUMBER
Hash value of the 
MODULE
column
ACTION
Footref 1
VARCHAR2(32)
Name of the currently executing action as set by calling the
DBMS_APPLICATION_INFO.SET_ACTION
procedure
ACTION_HASH
NUMBER
Hash value of the 
ACTION
column
CLIENT_INFO
VARCHAR2(64)
Information set by the
DBMS_APPLICATION_INFO.SET_CLIENT_INFO
procedure
FIXED_TABLE_SEQUENCE
NUMBER
This contains a number that increases every time the session completes a call to the database and there has been an intervening select from a dynamic performance table. This column can be used by performance
monitors to monitor statistics in the database. Each time the performance monitor looks at the database, it only needs to look at sessions that are currently active or have a higher value in this column than the highest value that the performance monitor saw
the last time. All the other sessions have been idle since the last time the performance monitor looked at the database.
ROW_WAIT_OBJ#
NUMBER
Object ID for the table containing the row specified in
ROW_WAIT_ROW#
ROW_WAIT_FILE#
NUMBER
Identifier for the datafile containing the row specified in
ROW_WAIT_ROW#
. This column is valid only if the session is currently waiting for another transaction to commit and the value of
ROW_WAIT_OBJ#
is not 
-1
.
ROW_WAIT_BLOCK#
NUMBER
Identifier for the block containing the row specified in
ROW_WAIT_ROW#
. This column is valid only if the session is currently waiting for another transaction to commit and the value of
ROW_WAIT_OBJ#
is not 
-1
.
ROW_WAIT_ROW#
NUMBER
Current row being locked. This column is valid only if the session is currently waiting for another transaction to commit and the value of
ROW_WAIT_OBJ#
is not 
-1
.
TOP_LEVEL_CALL#
NUMBER
Oracle top level call number
LOGON_TIME
DATE
Time of logon
LAST_CALL_ET
NUMBER
If the session 
STATUS
is currently
ACTIVE
, then the value represents the elapsed time (in seconds) since the session has become active.
If the session 
STATUS
is currently 
INACTIVE
, then the value represents the elapsed time (in seconds) since the session has become inactive.

PDML_ENABLED
VARCHAR2(3)
This column has been replaced by the
PDML_STATUS
column
FAILOVER_TYPE
VARCHAR2(13)
Indicates whether and to what extent transparent application failover (TAF) is enabled for the session:

NONE
- Failover is disabled for this session

SESSION
- Client is able to fail over its session following a disconnect

SELECT
- Client is able to fail over queries in progress as well

See Also:

Oracle Database Concepts for more information on TAF

Oracle Database Net Services Administrator's Guide for information on configuring TAF

FAILOVER_METHOD
VARCHAR2(10)
Indicates the transparent application failover method for the session:

NONE
- Failover is disabled for this session

BASIC
- Client itself reconnects following a disconnect

PRECONNECT
- Backup instance can support all connections from every instance for which it is backed up

FAILED_OVER
VARCHAR2(3)
Indicates whether the session is running in failover mode and failover has occurred (
YES
) or not (
NO
)
RESOURCE_CONSUMER_GROUP
VARCHAR2(32)
Name of the session's current resource consumer group
PDML_STATUS
VARCHAR2(8)
If 
ENABLED
, the session is in a
PARALLEL
DML
enabled mode. If 
DISABLED
, 
PARALLEL
DML
enabled mode is not supported for the session. If
FORCED
, the session has been altered to force 
PARALLEL
DML
.
PDDL_STATUS
VARCHAR2(8)
If 
ENABLED
, the session is in a
PARALLEL
DDL
enabled mode. If 
DISABLED
, 
PARALLEL
DDL
enabled mode is not supported for the session. If
FORCED
, the session has been altered to force 
PARALLEL
DDL
.
PQ_STATUS
VARCHAR2(8)
If 
ENABLED
, the session is in a
PARALLEL
QUERY
enabled mode. If 
DISABLED
, 
PARALLEL
QUERY
enabled mode is not supported for the session. If
FORCED
, the session has been altered to force 
PARALLEL
QUERY
.
CURRENT_QUEUE_DURATION
NUMBER
If queued (
1
), the current amount of time the session has been queued. If not currently queued, the value is
0
.
CLIENT_IDENTIFIER
VARCHAR2(64)
Client identifier of the session
BLOCKING_SESSION_STATUS
VARCHAR2(11)
This column provides details on whether there is a blocking session:

VALID
- there is a blocking session, and it is identified in the 
BLOCKING_INSTANCE
and 
BLOCKING_SESSION
columns

NO HOLDER
- there is no session blocking this session

NOT IN WAIT
- this session is not in a wait

UNKNOWN
- the blocking session is unknown

BLOCKING_INSTANCE
NUMBER
Instance identifier of the blocking session. This column is valid only if
BLOCKING_SESSION_STATUS
has the value 
VALID
.
BLOCKING_SESSION
NUMBER
Session identifier of the blocking session. This column is valid only if
BLOCKING_SESSION_STATUS
has the value 
VALID
.
FINAL_BLOCKING_SESSION_STATUS
VARCHAR2(11)
The final blocking session is the final element in the wait chain constructed by following the sessions that are blocked by one another starting with this session. In the case of a cyclical wait chain,
one of the sessions in the wait chain will be chosen as the final blocker.
This column provides details on whether there is a final blocking session:

VALID
- there is a final blocking session and it is identified in the
FINAL_BLOCKING_INSTANCE
and 
FINAL_BLOCKING_SESSION
columns

NO HOLDER
- there is no session blocking this session

NOT IN WAIT
- this session is not in a wait

UNKNOWN
- the final blocking session is unknown

FINAL_BLOCKING_INSTANCE
NUMBER
Instance identifier of the final blocking session. This column is valid only if
FINAL_BLOCKING_SESSION_STATUS
has the value 
VALID
.
FINAL_BLOCKING_SESSION
NUMBER
Session identifier of the blocking session. This column is valid only if
FINAL_BLOCKING_SESSION_STATUS
has the value 
VALID
.
SEQ#
NUMBER
A number that uniquely identifies the current or last wait (incremented for each wait)
EVENT#
NUMBER
Event number
EVENT
VARCHAR2(64)
Resource or event for which the session is waiting
See Also:
Appendix C, "Oracle Wait Events"

P1TEXT
VARCHAR2(64)
Description of the first wait event parameter
P1
NUMBER
First wait event parameter (in decimal)
P1RAW
RAW(8)
First wait event parameter (in hexadecimal)Foot 2 
P2TEXT
VARCHAR2(64)
Description of the second wait event parameter
P2
NUMBER
Second wait event parameter (in decimal)
P2RAW
RAW(8)
Second wait event parameter (in hexadecimal)Footref 2
P3TEXT
VARCHAR2(64)
Description of the third wait event parameter
P3
NUMBER
Third wait event parameter (in decimal)
P3RAW
RAW(8)
Third wait event parameter (in hexadecimal)Footref 2
WAIT_CLASS_ID
NUMBER
Identifier of the class of the wait event
WAIT_CLASS#
NUMBER
Number of the class of the wait event
WAIT_CLASS
VARCHAR2(64)
Name of the class of the wait event
WAIT_TIME
NUMBER
If the session is currently waiting, then the value is
0
. If the session is not in a wait, then the value is as follows:

> 
0
- Value is the duration of the last wait in hundredths of a second

-1
- Duration of the last wait was less than a hundredth of a second

-2
- Parameter 
TIMED_STATISTICS
was set to 
false


This column has been deprecated in favor of the columns 
WAIT_TIME_MICRO
and
STATE
.

SECONDS_IN_WAIT
NUMBER
If the session is currently waiting, then the value is the amount of time waited for the current wait. If the session is not in a wait, then the value is the amount of time since the start of the last
wait.
This column has been deprecated in favor of the columns 
WAIT_TIME_MICRO
and
TIME_SINCE_LAST_WAIT_MICRO
.

STATE
VARCHAR2(19)
Wait state:

WAITING
- Session is currently waiting

WAITED UNKNOWN TIME
- Duration of the last wait is unknown; this is the value when the parameter
TIMED_STATISTICS
is set to 
false


WAITED SHORT TIME
- Last wait was less than a hundredth of a second

WAITED KNOWN TIME
- Duration of the last wait is specified in the
WAIT_TIME
column

WAIT_TIME_MICRO
NUMBER
Amount of time waited (in microseconds). If the session is currently waiting, then the value is the time spent in the current wait. If the session is currently not in a wait, then the value is the amount
of time waited in the last wait.
TIME_REMAINING_MICRO
NUMBER
Value is interpreted as follows:

> 
0
- Amount of time remaining for the current wait (in microseconds)

0
- Current wait has timed out

-1
- Session can indefinitely wait in the current wait

NULL - Session is not currently waiting

TIME_SINCE_LAST_WAIT_MICRO
NUMBER
Time elapsed since the end of the last wait (in microseconds). If the session is currently in a wait, then the value is
0
.
SERVICE_NAME
VARCHAR2(64)
Service name of the session
SQL_TRACE
VARCHAR2(8)
Indicates whether SQL tracing is enabled (
ENABLED
) or disabled (
DISABLED
)
SQL_TRACE_WAITS
VARCHAR2(5)
Indicates whether wait tracing is enabled (
TRUE
) or not (
FALSE
)
SQL_TRACE_BINDS
VARCHAR2(5)
Indicates whether bind tracing is enabled (
TRUE
) or not (
FALSE
)
SQL_TRACE_PLAN_STATS
VARCHAR2(10)
Frequency at which row source statistics are dumped in the trace files for each cursor:

never


first_execution


all_executions


SESSION_EDITION_ID
NUMBER
Shows the value that, in the session, would be reported by
sys_context('USERENV', 'SESSION_EDITION_ID')
CREATOR_ADDR
RAW(4 | 8)
Address of the creating process or circuit
CREATOR_SERIAL#
NUMBER
Serial number of the creating process or circuit
ECID
VARCHAR2(64)
Execution context identifier (sent by Application Server)
Footnote 1 The datatype of this column is
VARCHAR2(64)
starting with Oracle Database 11g Release 2 (11.2.0.2).
Footnote 2 The 
P1RAW
,
P2RAW
, and 
P3RAW
columns display the same values as the
P1
, 
P2
, and 
P3
columns, except that the numbers are displayed in hexadecimal.

See Also:

Oracle Database Performance Tuning Guide for an example of using
V$SESSION
to determine which sessions are waiting for I/O

Oracle Database Performance Tuning Guide for an example of using
V$SESSION
to help identify an object that is waiting for buffer busy waits
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