Oracle 视图 DBA_ADVISOR_RECOMMENDATIONS 官方解释，作用，如何使用详细说明
本站中文解释
视图
Oracle视图DBA_ADVISOR_RECOMMENDATIONS是在数据库客户端提供的一种特殊视图，它显示给定数据库中正在执行的建议者的推荐结果。通过此视图可以查询出一些重要的建议，例如在某些特定情况下是否需要经常进行统计更新、或者是否需要运行特定的统计收集计划、或者提示用户完成某些数据库的优化等等。这些建议有助于用户改善系统的性能。使用方法：
1. 在sqlplus 进入数据库并登录，执行如下查询：
SELECT task_name, execution_start, execution_end, recommendations FROM dba_advisor_recommendations;
2. 查看输出结果，根据结果进行相应的优化。
官方英文解释
DBA_ADVISOR_RECOMMENDATIONS displays the results of an analysis of all recommendations in the database.
A recommendation can have multiple actions associated with it. Actions are described in the DBA_ADVISOR_ACTIONS view. A recommendation also points to a set of rationales that present a justification/reasoning for that recommendation. These rationales are in the DBA_ADVISOR_RATIONALE view.
Related View
USER_ADVISOR_RECOMMENDATIONS displays the results of an analysis of the recommendations owned by the current user. This view does not display the OWNER column.
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Owner of the task |
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Unique identifier of the recommendation |
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Task that owns the recommendation |
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Name of the task |
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The name of the task execution with which this entry (row) is associated |
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Unique identifier of the finding |
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Type of the recommendation |
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Ranking, in terms of importance, within the set of recommendations generated for the task |
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Comma-separated list of the recommendation IDs of the parent recommendations. If this column is nonzero, then the recommendation depends on the parents, and cannot be accepted if the parents are not accepted. |
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Describes the benefit obtained by carrying out the recommendation If there is a set of parents for the recommendation, then the benefit is the cumulative benefit (the improvement in system performance when this and all prior parent recommendations are accepted). If there are no parents, then this is the improvement when the recommendation is accepted, independent of other recommendations. |
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Calculated benefit value This column displays an estimate of the savings in total activity (or load) on the system if all actions of the recommendation are implemented. Recommendations are not additive, that is, the benefit from one recommendation may overlap with the benefit from another. For example, Oracle might recommend increasing the shared pool size, or reducing hard parses (by not using literals), and both recommendations might reduce the same part of the workload related to parsing. The benefit is given in both pure active sessions and as a percent of the average active sessions of the analysis time period. Therefore, if the benefit is 20% of active sessions, Oracle estimates that if you apply the actions on the same workload, the average active sessions on the server will be reduced by 20%. The |
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When a task is complete, the recommendations are marked
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Advisor-specific flags |
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A value of |
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Recommendation type ID |
See Also:
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“USER_ADVISOR_RECOMMENDATIONS”
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“DBA_ADDM_TASKS”
