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

本站中文解释

Oracle视图是一种结构化的数据存储，存储用户可以查询的数据，比如元数据、表达式、函数等。 Oracle视图DBA_HIST_MEMORY_TARGET_ADVICE提供有关内存大小和工作负载状态的建议，以管理数据库的性能。

使用Oracle视图DBA_HIST_MEMORY_TARGET_ADVICE，可以对数据库的内存大小和工作负载状况进行观察，以改善数据库的性能。

用户可以在Oracle数据库中查询查看Oracle视图DBA_HIST_MEMORY_TARGET_ADVICE中存储的信息，比如有多少可用的内存量，建议的内存大小，活动的工作负载状态等等，以便优化数据库的性能。

另外，用户可以使用V$MEMORY_TARGET_ADVICE视图来识别正在运行时内存调整建议，并使用DBA_HIST_MEMORY_TARGET_ADVICE视图来获取历史记录。

官方英文解释

DBA_HIST_MEMORY_TARGET_ADVICE displays memory target advice history.

This view contains snapshots of V$MEMORY_TARGET_ADVICE.

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

MEMORY_SIZE

NUMBER

NOT NULL

If the MEMORY_SIZE_FACTOR column has a value of 1, then this column shows the current size of memory, as set by the MEMORY_TARGET initialization parameter.

If the value of the MEMORY_SIZE_FACTOR column is less than or greater than 1, then this column shows a proposed memory size.

MEMORY_SIZE_FACTOR

NUMBER

A multiplier for the current memory size. Possible values are 0.25, 0.5, 0.75, 1, 1.5, 1.75 and 2. This multiplier times the current memory size equals the value of the MEMORY_SIZE column.

ESTD_DB_TIME

NUMBER

For current memory size (MEMORY_SIZE_FACTOR = 1), the amount of database time required to complete the current workload. For a proposed memory size, the estimated amount of database time that would be required if the MEMORY_TARGET parameter were changed to the proposed size.

ESTD_DB_TIME_FACTOR

NUMBER

For a proposed memory size, ratio of estimated database time to current database time

VERSION

NUMBER

Version number of this recommendation

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

See Also:

“V$MEMORY_TARGET_ADVICE”


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