最近我阅读了更多关于“优化统计顾问”,我做了一些测试我的测试数据库。它给了下面的建议:
Rule Name: UseConcurrent
Rule Description: Use Concurrent preference for Statistics Collection
Finding: The CONCURRENT preference is not used.
Recommendation: Set the CONCURRENT preference.
Example:
dbms_stats.set_global_prefs('CONCURRENT', 'ALL');
Rationale: The system's condition satisfies the use of concurrent statistics
gathering. Using CONCURRENT increases the efficiency of statistics
gathering.
据我从甲骨文公司了解
Concurrent statistics collection is simply the ability to gather statistics on multiple tables, or table partitions, at the same time. This is done using a combination of the job scheduler, advanced queuing and resource manager.
因此,此建议适用于所有数据库,而不是表。我的意思是,如果我收集表的统计信息,这样的远程建议不会有任何好处,对吗?还有,是否有一种方法可以在特定表上实现“优化统计顾问”?
1条答案
按热度按时间bpsygsoo1#
Unlikely, because one of the overall aims for the optimizer team is that for 99% of customers, the default settings of the optimizer statistics gathering mechanisms will be sufficient to ensure good plans.
This is why (for example)
and so forth. The aim is that (except in niche cases) you'll not need to "worry" about the optimizer statistics process.