Oracle 视图 V$GC_ELEMENT 官方解释，作用，如何使用详细说明
本站中文解释
V$GC_ELEMENT是Oracle的一个系统视图，它描述一个叫Global Cache（全局缓存）的结构的各个元素，包括它们之间的关系。
Global Cache（全局缓存）是Oracle中用于同步本地数据库缓存和远程数据库缓存的一系列服务。它在数据库环境中提供高数据一致性级别，同时也支持高可用性，用于支持数据库片段化、主从部署等。
V$GC_ELEMENT提供如下用途：
1. 显示Global Cache配置信息，如域ID、状态、客户端类型等。
2. 动态查询Global Cache配置，如支持的数据库、表空间、表、视图等。
3. 针对特定的Global Cache环境，检查任何已经存在的元素是否具有合理的配置。
要使用V$GC_ELEMENT视图，可以使用SQL查询它，例如：
SELECT * FROM V$GC_ELEMENT
上述查询将读取V$GC_ELEMENT视图中的所有列，以显示当前Global Cache配置信息。
官方英文解释
V$GC_ELEMENT displays one entry for each global cache resource that is used by the buffer cache. The name of the global cache resource that corresponds to a lock element is {‘BL’, indx, class}. This is an Oracle Real Application Clusters view.
| Column | Datatype | Description |
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Address of the lock element that contains the PCM lock that is covering the buffer. If more than one buffer has the same address, then these buffers are covered by the same PCM lock. |
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Platform specific lock manager identifier |
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Platform specific lock manager identifier |
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Name of the lock that contains the PCM lock that is covering the buffer |
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Platform dependent value for lock mode held; often: 3 = share; 5 = exclusive |
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Number of blocks covered by PCM lock |
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Nonzero if PCM lock is being downgraded |
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Nonzero if PCM lock is being upgraded |
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If the GC_ELEMENT is being written, the write status |
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If the GC_ELEMENT is being recovered, the recovery status |
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Zero if the GC_ELEMENT is local, one if it is global |
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Process level flags for the lock element |
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The ID of the container to which the data pertains. Possible values include:
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