Oracle 视图 DBA_HIST_INST_CACHE_TRANSFER 官方解释，作用，如何使用详细说明
本站中文解释
dba_hist_inst_cache_transfer 表是 Oracle 的 AWR 报告的一个动态性能视图，它包含用于跨实例缓存传输历史的拆分缓存转移信息，并且在表中维护这些信息以及缓存大小和转移时间戳信息。
dba_hist_inst_cache_transfer 视图帮助数据库管理员和性能分析师确定在跨实例分离缓存传输期间消耗的资源，从而更好地理解数据库活动。视图中的每一行记录代表一次拆分缓存传输，其字段包括来源实例，目标实例以及转移的元素的缓存大小。
使用该视图的主要用途是监视执行的缓存传输量，及相关联的缓存投入，以发现可能的增益。它可以用来识别在跨实例缓存传输操作中发生的困难，及监视两个实例之间缓存累积情况，以便确定可以通过操作改善性能的机会以及优化性能的必要性。
官方英文解释
DBA_HIST_INST_CACHE_TRANSFER displays the historical statistics on the cache blocks transferred among instances.
This view contains snapshots of V$INSTANCE_CACHE_TRANSFER.
| Column | Datatype | NULL | Description |
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Unique snapshot ID |
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Database ID for the snapshot |
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Instance number for the snapshot |
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Instance from which the blocks are transferred |
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Class of the cache block |
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CR block transfers not affected by remote processing delays |
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Current block transfers affected by remote contention |
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CR block transfers affected by remote system load |
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Current block transfers not affected by remote processing delays |
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Current block transfers affected by remote contention |
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Current block transfers affected by remote system load |
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The number of blocks that were sent by a particular instance but that never arrived in this instance |
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The count of CR blocks which were received by this instance from a particular instance after a 2-way round-trip |
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The count of CR blocks which were received by this instance from a particular instance after a 3-way round-trip |
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The count of CR Blocks which were directly read from a remote instance via RDMA |
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The count of current blocks which were received by this instance from a particular instance after a 2-way round-trip |
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The count of current blocks which were received by this instance from a particular instance after a 3-way round-trip |
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The count of current blocks which were directly read from a remote instance via RDMA |
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Total time waited for CR blocks from a particular instance (includes the other times) |
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The time waited for CR blocks which were received by this instance from a particular instance and which were delayed by a log flushed on the sending instance |
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The time waited for CR blocks which were received by this instance from a particular instance and which were delayed because LMS was busy |
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Total time waited for CR blocks from a particular instance (includes the other times) |
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The time waited for current blocks which were received by this instance from a particular instance and which were delayed by a log flushed on the sending instance |
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The time waited for current blocks which were received by this instance from a particular instance and which were delayed because LMS was busy |
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The time waited for blocks that were sent by a particular instance but that never arrived in this instance |
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The time waited for CR blocks which were received by this instance from a particular instance after a 2-way round-trip |
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The time waited for CR blocks which were received by this instance from a particular instance after a 3-way round-trip |
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Total time waited to directly read CR blocks from a remote instance via RDMA (in centiseconds) |
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The time waited for current blocks which were received by this instance from a particular instance after a 2-way round-trip |
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The time waited for current blocks which were received by this instance from a particular instance after a 3-way round-trip |
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Total time waited to directly read current blocks from a remote instance via RDMA (in centiseconds) |
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The database ID of the PDB for the sampled session |
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The ID of the container that
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Footnote 1 This column is available starting with Oracle Database 21c.
See Also:
“V$INSTANCE_CACHE_TRANSFER”
