Oracle 视图 DBA_HIST_STREAMS_POOL_ADVICE 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_STREAMS_POOL_ADVICE提供了有关数据库流程缓冲池的历史建议。

它提供了一些有关数据库流程缓冲池和它们使用的建议。这些建议摘要性地揭示了应该修改数据库流池大小的可能性以改进流池的性能,或者说如果不进行修改,则影响相应流池的性能的可能性。

在Oracle RAC环境中,数据库管理员可以使用Oracle视图DBA_HIST_STREAMS_POOL_ADVICE,以获得在系统中各个节点上的历史流池数据,以评估这些系统的性能和空闲比例,以便对班可以进行优化。

使用Oracle视图DBA_HIST_STREAMS_POOL_ADVICE的步骤:

1)确定当前应用程序所使用的流池数据字典视图。

2)使用这些视图中提供的信息,查看内存分配、内存占用等相关信息。

3)使用DBA_HIST_STREAMS_POOL_ADVICE视图确定内存大小的变化,以及熵值的影响。

4)对比数据库的历史大小,将大小变化

官方英文解释

DBA_HIST_STREAMS_POOL_ADVICE displays historical information about the estimated count of spilled or unspilled messages and the associated time spent in the spill or unspill activity for different Streams pool sizes.

This view is intended for use with Automatic Workload Repository (AWR).

Column Datatype NULL Description

SNAP_ID

NUMBER

NOT NULL

Unique snapshot ID

DBID

NUMBER

NOT NULL

Database ID of the snapshot

INSTANCE_NUMBER

NUMBER

NOT NULL

Instance number of the snapshot

SIZE_FOR_ESTIMATE

NUMBER

NOT NULL

Pool size for the estimate (in megabytes)

SIZE_FACTOR

NUMBER

Size factor with respect to the current pool size

ESTD_SPILL_COUNT

NUMBER

Estimated count of messages spilled from the Streams pool

ESTD_SPILL_TIME

NUMBER

Estimated elapsed time (in seconds) to spill

ESTD_UNSPILL_COUNT

NUMBER

Estimated count of unspills (read back from disk)

ESTD_UNSPILL_TIME

NUMBER

Estimated elapsed time (in seconds) to unspill

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


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