Oracle教程 2023-02-27

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

_SUMMARY与V$SGA_TARGET

Oracle视图：DBA_HIST_SGA_SUMMARY

作用：
DBA_HIST_SGA_SUMMARY视图提供有关用于调查过去数小时中SGA物理内存大小的细节。它是一个把所有聚集在一起的AWR查询。

使用方法：
要使用DBA_HIST_SGA_SUMMARY视图，请运行以下简单查询：
SELECT *
FROM DBA_HIST_SGA_SUMMARY;

Oracle视图：V$SGA_TARGET

作用：
V$SGA_TARGET 视图显示了 SGA 的总大小以及每个 SGA 子组件的大小，因此允许你监控复制实例（数据库实例）共享内存池实例（SGA）的大小。

使用方法：
要使用 V$SGA_TARGET 视图，请运行以下简单查询：
SELECT *
FROM V$SGA_TARGET;

DBA_HIST_SGA displays historical summary information about the system global area (SGA).

This view contains snapshots of V$SGA.

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(64)`	`NOT NULL`	SGA component group
`VALUE`	`NUMBER`	`NOT NULL`	Memory size (in bytes)
`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