Oracle 视图 DBA_HEATMAP_TOP_OBJECTS 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_OBJECTS提供了一种简易的方法来确定影响性能的表或者索引的信息。它可以按照I/O使用率排序，帮助DBA快速确定那些表和索引有最高I/O使用率、最大pending I/O操作、最长读操作和最晚写操作时间等等~
使用 Oracle 视图 DBA_HEATMAP_TOP_OBJECTS， 需要准备如下三步：
1. 首先创建“正确”的表空间，然后在这个表空间中创建和加载性能信息。
2. 然后使用 Oracle 的analyze 来收集基本的统计信息，这个可以通过Oracle 优化器自动完成。
3. 最后可以使用 DBA_HEATMAP_TOP_OBJECTS视图，以找出相关的高I/O使用的表和索引。
官方英文解释
DBA_HEATMAP_TOP_OBJECTS displays heat map information for the top 10000 objects by default.
If the database contains fewer than 10000 objects, then fewer than 10000 objects are returned by the view.
| Column | Datatype | NULL | Description |
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Object owner |
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Object name |
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Object type |
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Tablespace name |
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Segments in the tablespace |
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Size of the object in MB |
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Oldest modification time for a set of blocks |
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Latest modification time for a set of blocks |
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Average of the modification times for a set of blocks |
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Oldest read time for a set of blocks |
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Latest read time for a set of blocks |
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Average of the read times for a set of blocks |
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Minimum full table scan time of the object |
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Maximum full table scan time of the object |
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Average full table scan time of the object |
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Minimum lookup time of the object |
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Maximum lookup time of the object |
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Average lookup time of the object |
