Oracle教程 2023-03-24

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

本站中文解释

V$CLASS_CACHE_TRANSFER视图用于查看当前已缓冲和正在缓冲中的类，以及从SGA缓存中请求类和返回数据时的时间和将数据传给应用程序所花费的时间。

该视图具有有以下列：

• buffer_hits：缓冲命中次数
• buffer_misses：缓冲错误次数
• Class Type：Run time 还是View time类
• Class Name：类名
• Class Type ID：类型标识符
• Processed Blocks：处理的块数
• Request Time：从SGA缓存中请求类的时间
• Return Time：将数据传给应用程序所花费的时间
• Requests：请求数

V$CLASS_CACHE_TRANSFER视图可以用于监控Oracle数据库系统以及检测性能问题。

使用方法：

使用V$CLASS_CACHE_TRANSFER视图，你可以执行以下SQL脚本：

SELECT *
FROM V$CLASS_CACHE_TRANSFER
WHERE buffer_hits / (buffer_misses + buffer_hits)

官方英文解释

V$CLASS_CACHE_TRANSFER is deprecated. The information that was provided in this view is now provided in the V$INSTANCE_CACHE_TRANSFER and V$SEGMENT_STATISTICS views.

Column	Datatype	Description
`CLASS`	`CHAR(10)`	Block class; always `data block`
`X_2_NULL`	`NUMBER`	Number of blocks with Exclusive-to-NULL conversions; always `0`
`X_2_NULL_FORCED_WRITE`	`NUMBER`	Number of Exclusive-to-NULL forced writes; always `0`
`X_2_NULL_FORCED_STALE`	`NUMBER`	Number of Exclusive-to-NULL blocks converted to CR; always `0`
`X_2_S`	`NUMBER`	Number of blocks with Exclusive-to-Shared conversions; always `0`
`X_2_S_FORCED_WRITE`	`NUMBER`	Number of Exclusive-to-Shared forced writes; always `0`
`S_2_NULL`	`NUMBER`	Number of blocks with Shared-to-NULL conversions; always `0`
`S_2_NULL_FORCED_STALE`	`NUMBER`	Number of Shared-to-NULL blocks converted to CR; always `0`
`NULL_2_X`	`NUMBER`	Number of blocks with NULL-to-Exclusive conversions; always `0`
`S_2_X`	`NUMBER`	Number of blocks with Shared-to-Exclusive conversions; always `0`
`NULL_2_S`	`NUMBER`	Number of blocks with NULL-to-Shared conversions; always `0`
`CR_TRANSFER`	`NUMBER`	Number of CR blocks transferred; always `0`
`CURRENT_TRANSFER`	`NUMBER`	Number of current blocks transferred; always `0`
`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

本站中文解释

官方英文解释

相关推荐