Oracle 视图 DBA_HIST_IC_CLIENT_STATS 官方解释,作用,如何使用详细说明

本站中文解释

Oracle视图DBA_HIST_IC_CLIENT_STATS提供了对客户端轮次执行优化进程(IC)中收集的统计信息进行查询的能力。每个时间点(可以是数据库快照或AWR收集的报告)都会捕获IC运行的状态,包括执行的视图、表或驱动查询的索引扫描数量。

可以使用DBA_HIST_IC_CLIENT_STATS视图定位特定许可证用户或特定查询期间在表或索引上执行的扫描量。 通过查询该视图,您可以了解查询的索引使用情况和查询的性能。以便根据这些信息优化数据库中的表和索引。此外,由于它们可以提供信息有关正在正确使用数据库、正确使用数据库进行优化以及为查询提供最优性能的信息,因此还可以使用它来评估应用程序的性能。

要查询DBA_HIST_IC_CLIENT_STATS视图,必须以SYSDBA或SYSOPER角色。 例如,要查看在特定日期上下文之间,所有许可证用户的索引扫描次数,可以使用以下查询:

SELECT
LICENSE_ID,
COUNT(“INDEX SCAN COUNT”) AS “INDEX_SCAN_COUNT”
FROM DBA_HIST_IC_CLIENT_STATS
WHERE SNAP_ID BETWEEN :START_SNAP_ID AND :END_SNAP_ID
GROUP BY LICENSE_ID;

官方英文解释

DBA_HIST_IC_CLIENT_STATS displays information about the usage of an interconnect device by the instance.

The information is divided into several areas of the Oracle Database, each identified by the NAME value.

Column Datatype NULL Description

SNAP_ID

NUMBER

NOT NULL

Unique snapshot ID

DBID

NUMBER

NOT NULL

Database ID for the snapshot

INSTANCE_NUMBER

NUMBER

NOT NULL

Instance number for the snapshot

NAME

VARCHAR2(9)

NOT NULL

Identifies the area of the Oracle Database:

  • ipq – Parallel query communications

  • dlm – Database lock management

  • cache – Global cache communications

All other values are internal to Oracle and are not expected to have high usage.

BYTES_SENT

NUMBER

Number of bytes sent by the instance since instance startup for the software area identified by NAME. This information is aggregated across all devices used by the instance.

BYTES_RECEIVED

NUMBER

Number of bytes received by the instance since instance startup for the software area identified by NAME. This information is aggregated across all devices used by the instance.

CON_DBID

NUMBER

The database ID of the PDB for the sampled session

CON_ID

NUMBER

The ID of the container that CON_DBID identifies. 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


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