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 |
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Row cache ID number |
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Parent or subordinate row cache type |
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Subordinate set number |
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Name of the initialization parameter that determines the number of entries in the data dictionary cache |
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Total number of entries in the cache |
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Number of cache entries that contain valid data |
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Number of fixed entries in the cache |
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Total number of requests for information on the data object |
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Reserved for internal use |
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Number of data requests resulting in cache misses |
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Number of scan requests |
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Number of times a scan failed to find the data in the cache |
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For a list of subordinate entries, the number of times the list was scanned completely |
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Number of inserts, updates, and deletions |
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Number of times flushed to disk |
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Number of DLM requests |
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Number of DLM conflicts This column is obsolete and is maintained for backward compatibility. |
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Number of DLM releases This column is obsolete and is maintained for backward compatibility. |
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The ID of the container to which the data pertains. Possible values include:
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