Oracle 视图 DBA_HEATMAP_TOP_TABLESPACES 官方解释，作用，如何使用详细说明
本站中文解释
Oracle视图DBA_HEATMAP_TOP_TABLESPACES是自Oracle 12c新增的视图，提供了表空间热点概览分析功能。它使用內部注册信息组合表空间活动（如AQ），应用程序、会话或等在给定时间点的表空间访问活动。它可以有助于把握系统中最负责的表空间的活动，以及用于监视和改进表空间性能的建议。
使用方法：
1.查询DBA_HEATMAP_TOP_TABLESPACES视图，可以查询出时间段内最活跃的表空间的活动，如：
SELECT * FROM DBA_HEATMAP_TOP_TABLESPACES;
2.可以在查询所有表空间的基础上，分类查询结果：
SELECT tablespace_name，
SUM (read_count)、
SUM (write_delay_time)
FROM DBA_HEATMAP_TOP_TABLESPACES
GROUP BY tablespace_name;
3.也可以查询指定表空间的活动：
SELECT *
FROM DBA_HEATMAP_TOP_TABLESPACES
WHERE tablespace_name = ‘system’;
官方英文解释
DBA_HEATMAP_TOP_TABLESPACES displays heat map information for the top 100 tablespaces.
| Column | Datatype | NULL | Description |
|---|---|---|---|
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Tablespace name |
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Segments in the tablespace |
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Total bytes allocated to the objects in the tablespace |
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Minimum write time of objects tracked |
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Maximum write time of objects tracked |
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Average write time of objects tracked |
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Minimum read time of objects tracked |
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Maximum read time of objects tracked |
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Average read time of objects tracked |
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Minimum full table scan time of objects tracked |
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Maximum full table scan time of objects tracked |
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Average full table scan time of objects tracked |
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Minimum lookup time of objects tracked |
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Maximum lookup time of objects tracked |
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Average lookup time of objects tracked |
