Oracle 视图 V$ACTIVE_SERVICES 官方解释,作用,如何使用详细说明

本站中文解释

Oracle 数据库中的V$ACTIVE_SERVICES视图用于检索当前正在运行的服务信息。

V$ACTIVE_SERVICES视图可用于检索当前正在运行的服务的信息,postpone_time可用于判断缓解周期耗尽时间,因为同一服务有在并发技术中可能有多个session, V$ACTIVE_SERVICES可以区分它们,可以检查哪些服务以及哪些请求对特定类型的服务进行排队等等。

V$ACTIVE_SERVICES 视图可用于在Oracle数据库中通过以下select 语句来使用:

SELECT * FROM V$ACTIVE_SERVICES;

官方英文解释

V$ACTIVE_SERVICES displays information about the active services in the database.

Column Datatype Description

SERVICE_ID

NUMBER

Service ID

NAME

VARCHAR2(64)

Name of the service

NAME_HASH

NUMBER

Service name hash

NETWORK_NAME

VARCHAR2(512)

Network name

CREATION_DATE

DATE

Creation date

CREATION_DATE_HASH

NUMBER

Creation date hash

GOAL

VARCHAR2(12)

Runtime Load Balancing Goal being used to create run-time load balancing and connection load balancing advice:

  • NONE

  • SERVICE_TIME – Connections are balanced by response time

  • THROUGHPUT – Connections are balanced by throughput

DTP

VARCHAR2(1)

Indicates whether or not Distributed Transaction Processing is enabled for this service. When Distributed Transaction Processing is set to Y (YES), it means that the service is offered at exactly one instance at a time for XA affinity. Possible values:

  • Y – YES

  • N – NO

BLOCKED

CHAR(2)

Indicates whether a service on the specified instance is blocked from accepting new connections altogether (YES) or not (NO). If a service is blocked, then all connections will be directed to other instances (if any) that are hosting the desired service.

AQ_HA_NOTIFICATION

VARCHAR2(3)

Indicates whether FAN – Fast Application Notification for OCI connections is set (YES) or not (NO)

CLB_GOAL

VARCHAR2(5)

Connection load balancing goal used with statistics that are sent to the listeners to determine how new connections are distributed:

  • LONG

  • SHORT

COMMIT_OUTCOME

VARCHAR2(3)

For Transaction Guard, indicates whether the database service associated with the user session has the COMMIT_OUTCOME service attribute enabled (YES) or not (NO). This attribute applies on a per session basis and is set at connect time.

When COMMIT_OUTCOME = YES:

  • Transaction Guard manages the commit status for all supported transaction types. The outcome of a COMMIT transaction is known. If there is an outage, the application can use DBMS_APP_CONT.GET_LTXID_OUTCOME to return a reliable status for the last in-flight work.

  • A logical transaction ID (LTXID) is set for each user session at login and at each successful commit.

See Also: For information about preserving the commit outcome, see Oracle Database
Development Guide
. For information about logical transaction IDs, see Oracle Database
Development Guide

RETENTION_TIME

NUMBER

For Transaction Guard, when COMMIT_OUTCOME = YES, this value indicates the amount of time (in seconds) that the commit outcome is retained in the database.

REPLAY_INITIATION_TIMEOUT

NUMBER

For Application Continuity, this option specifies the difference between the time (in seconds) of original execution of the first operation of a request and the time that the replay is ready to start after a successful reconnect. Application Continuity will not replay after the specified amount of time has passed. This option is intended to avoid the unintentional execution of a transaction when a system is recovered after a long period of time. The default is 5 minutes (300 seconds).

SESSION_STATE_CONSISTENCY

VARCHAR2(128)

Describes how non-transactional is changed during a request. This parameter is considered only if failover_type is set to TRANSACTION for Application Continuity. Examples of session state are NLS settings, optimizer preferences, event settings, PL/SQL global variables, temporary tables, advanced queues, LOBs, and result cache. If non-transactional values change after the request starts, the default value of DYNAMIC should be set. Almost all applications should use DYNAMIC mode. If you are unsure, use DYNAMIC mode.

GLOBAL

VARCHAR2(3)

Indicates whether the service is global. A global service is managed by Global Service Manager (GSM) and can be provided by multiple databases that contain replicated data. Possible values:

  • YES: Indicates the service is global

  • NO: Indicates the service is not global

CON_NAME

VARCHAR2(128)

Container name of the object. The value of this column is NULL in non-CDBs.

SQL_TRANSLATION_PROFILE

VARCHAR2(261)

A non-NULL value specifies the initial SQL translation profile for subsequent database connections that use the service and do not specify a SQL translation profile. A NULL value has no effect.

MAX_LAG_TIME

VARCHAR2(128)

The maximum replication lag (in seconds) that is acceptable for a data replica to be used for providing the database service. Can only be specified for global services.

STOP_OPTION

VARCHAR2(128)

Stop option for sessions of this service for planned maintenance

FAILOVER_RESTORE

VARCHAR2(128)

Indicates whether sessions recover their commonly used session state (like NLS, schema) when they are failed over with TAF

DRAIN_TIMEOUT

NUMBER

Number of seconds to wait for sessions to be drained

TABLE_FAMILY_ID

NUMBER

Sharded table family ID associated with the service

PLACEMENT_TEMPLATE

VARCHAR2(64)

Reserved for future use

COMMIT_OUTCOME_FASTPATH

VARCHAR2(3)

Reserved for future use

CON_ID

NUMBER

The ID of the container to which the data pertains. Possible values include:

  • 0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.

  • 1: This value is used for rows containing data that pertain to only the root

  • n: Where n is the applicable container ID for the rows containing data


数据运维技术 » Oracle 视图 V$ACTIVE_SERVICES 官方解释,作用,如何使用详细说明