Oracle 视图 V$ROWCACHE 官方解释,作用,如何使用详细说明
本站中文解释
Oracle视囑V$ROWCACHE用于查看数据库缓存中正在被缓存的行,专为Oracle数据库提供缓存管理服务,监控数据库缓存中被缓存的行。该视图使用Oracle内部自动内存管理技术(AMM),跟踪被缓存的行的使用情况,方便管理员进行性能调整与维护。
使用步骤:
1. 首先登录到数据库。
2. 使用SQL指令:SELECT * FROM v$rowcache运行V$ROWCACHE视图,查看数据库缓存当前被缓存的行。
3. 查看视图的列:ADDRESS,KGLHNDL,KGLNAOH,NAMESPACE,NAMESPACE,NFIXEDSCN,CCHSCN,HOLD,CHGIND,CLASS,INDEX,CHGTM。
4. 根据不同场景,可以添加where子句以细化查询结果,如:SELECT * FROM v$rowcache WHERE CLASS = 200;
5. 考察结果,以了解不同场景下缓存的行的使用情况,可以根据行使用情况,调整数据库性能。
官方英文解释
V$ROWCACHE
displays statistics for data dictionary activity. Each row contains statistics for one data dictionary cache.
Column | Datatype | Description |
---|---|---|
|
| Row cache ID number |
|
| Parent or subordinate row cache type |
|
| Subordinate set number |
|
| Name of the initialization parameter that determines the number of entries in the data dictionary cache |
|
| Total number of entries in the cache |
|
| Number of cache entries that contain valid data |
|
| Number of fixed entries in the cache |
|
| Total number of requests for information on the data object |
|
| Reserved for internal use |
|
| Number of data requests resulting in cache misses |
|
| Number of scan requests |
|
| Number of times a scan failed to find the data in the cache |
|
| For a list of subordinate entries, the number of times the list was scanned completely |
|
| Number of inserts, updates, and deletions |
|
| Number of times flushed to disk |
|
| Number of DLM requests |
|
| Number of DLM conflicts This column is obsolete and is maintained for backward compatibility. |
|
| Number of DLM releases This column is obsolete and is maintained for backward compatibility. |
|
| The ID of the container to which the data pertains. Possible values include:
|
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标签:缓存,数据库,视图,情况,中正