删除带有查询的表访问已满 [英] removing Table Access Full with query

问题描述

谁能解释一下如何使用Oracle Query删除Table Access Full，查询花费的时间太长，无法给出结果.

Can any one explain how to remove Table Access Full with Oracle Query, query is taking too long to give the results.

推荐答案

如果您的查询使用的是全表扫描的原因可能是:
-索引不足
-统计信息已过时
-优化器无法计算正确的访问路径

最可能的原因是第一个:索引不足.因此，根据您提供的信息，请查看查询并尝试创建一个至少满足条件中使用的最重要列的索引.

另一件事是，如果查询返回很多行，请考虑分页结果而不是一次获取所有数据.这可能有助于获得较大的结果集.

If your query is using a full table scan the reason could be:
- insufficient indexing
- statistics are out of date
- the optimizer isn''t able to calculate the correct access path

The most likely reason is the first one: insufficient indexing. So based on the information you have provided, have a look at the query and try to create an index that would satisfy at least the most important columns used in your criteria.

Another thing is that if the query is returning a lot of rows, consider paging the results instead of getting all of the data at once. This could help with large result sets.

这篇关于删除带有查询的表访问已满的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！