session和v$session說明

Column

Datatype

Description

說明

SADDR

RAW(4 | 8)

Session address

SID

NUMBER

Session identifier

透過這兩個值來確定唯一的一個session

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

If AUDSID=0, then it is an internally generated SYS session.  

If AUDSID=UB4MAX(4294967295), then it is a direct SYS session. 

PADDR

RAW(4 | 8)

Address of the process that owns the session

process address,關聯v$process的addr欄位

USER#

NUMBER

Oracle user identifier

同dba_users關聯

USERNAME

VARCHAR2(30)

Oracle username

同dba_users

COMMAND

NUMBER

Command in progress (last statement parsed).

session正在執行的sql id，1代表create table,3代表select

You can find the command name for any value n returned in thisCOMMAND 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

當前的transaction address。可以用來關聯v$transaction中的addr欄位

LOCKWAIT

VARCHAR2(8)

Address of the lock the session is waiting for; NULL if none

 可以透過這個欄位查詢出當前正在等待的鎖的相關資訊。sid + lockwait與v$loc中的sid + kaddr相對應。

STATUS

VARCHAR2(8)

Status of the session:

用來判斷session狀態。Active:正執行SQL語句。inactive:等待操作。killed:被標註為殺死

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:

服務型別（一般專用型別）

DEDICATED

SHARED

PSEUDO

POOLED

NONE

SCHEMA#

NUMBER

Schema user identifier

跟USER#一致

SCHEMANAME

VARCHAR2(30)

Schema user name

跟USERNAME一致

OSUSER

VARCHAR2(30)

Operating system client user name

客戶端作業系統使用者名稱

PROCESS

VARCHAR2(24)

Operating system client process ID

客戶端process id

MACHINE

VARCHAR2(64)

Operating system machine name

客戶端machine name

PORT

NUMBER

Client port number

客戶端的埠號

TERMINAL

VARCHAR2(30)

Operating system terminal name

客戶端執行的terminal name

PROGRAM

VARCHAR2(48)

Operating system program name

客戶端應用程式

TYPE

VARCHAR2(10)

Session type

使用者程式還是後臺程式，後臺程式一般不能KILL

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

當前被執行的SQL語句，跟v$sql關聯

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

當前sql的開始執行時間

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

剛被執行的SQL語句，從v$sql查詢相應的SQL語句

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

VARCHAR2(48)

Name of the currently executing module as set by calling theDBMS_APPLICATION_INFO.SET_MODULE procedure

MODULE_HASH

NUMBER

Hash value of the MODULE column

VARCHAR2(32)

Name of the currently executing action as set by calling theDBMS_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_INFOprocedure

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 inROW_WAIT_ROW#. This column is valid only if the session is currently waiting for another transaction to commit and the value ofROW_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 ofROW_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:

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. IfDISABLED, PARALLEL QUERY enabled mode is not supported for the session. If FORCED, the session has been altered to force PARALLELQUERY.

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 theBLOCKING_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 ifBLOCKING_SESSION_STATUS has the value VALID.

BLOCKING_SESSION

NUMBER

Session identifier of the blocking session. This column is valid only ifBLOCKING_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 theFINAL_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 ifFINAL_BLOCKING_SESSION_STATUS has the value VALID.

FINAL_BLOCKING_SESSION

NUMBER

Session identifier of the blocking session. This column is valid only ifFINAL_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

等待事件的編號跟v$session_wait關聯

EVENT

VARCHAR2(64)

Resource or event for which the session is waiting

等待事件的解釋跟v$session_wait關聯

P1TEXT

VARCHAR2(64)

Description of the first wait event parameter

對應DBA_EXTENTS的FILE_ID,BLOCK_ID,BLOCKS

P1

NUMBER

First wait event parameter (in decimal)

P1RAW

RAW(8)

P2TEXT

VARCHAR2(64)

Description of the second wait event parameter

P2

NUMBER

Second wait event parameter (in decimal)

P2RAW

RAW(8)

P3TEXT

VARCHAR2(64)

Description of the third wait event parameter

P3

NUMBER

Third wait event parameter (in decimal)

P3RAW

RAW(8)

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 columnsWAIT_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 columnsWAIT_TIME_MICRO and TIME_SINCE_LAST_WAIT_MICRO.

STATE

VARCHAR2(19)

Wait state:

WAITING - Session is currently waiting

當前session處於等待

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 theWAIT_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)

是否開啟跟蹤

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 bysys_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)