Oracle的IN vs OR，哪个更快? [英] IN vs OR of Oracle, which faster?

问题描述

我正在开发一个处理Oracle数据库中许多数据的应用程序.
在某些情况下，我必须根据给定的条件列表获取许多对象，并且使用SELECT ...FROM.. WHERE... IN...，但是IN表达式仅接受最大为1000个项目的列表.

I'm developing an application which processes many data in Oracle database.
In some case, I have to get many object based on a given list of conditions, and I use SELECT ...FROM.. WHERE... IN..., but the IN expression just accepts a list whose size is maximum 1,000 items.

所以我改用OR表达式，但是据我观察-也许此查询(使用OR)比IN(具有相同条件列表)要慢.这样对吗?如果可以，如何提高查询速度?

So I use OR expression instead, but as I observe -- perhaps this query (using OR) is slower than IN (with the same list of condition). Is it right? And if so, how to improve the speed of query?

推荐答案

IN比OR更可取--OR的性能差劲，并且可能导致其他问题，这些问题需要在复杂的查询中使用括号

IN is preferable to OR -- OR is a notoriously bad performer, and can cause other issues that would require using parenthesis in complex queries.

更好的选择是连接到包含所需(或不需要)值的表.该比较表可以派生，临时或已存在于您的模式中.

Better option than either IN or OR, is to join to a table containing the values you want (or don't want). This table for comparison can be derived, temporary, or already existing in your schema.

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