内联正则表达式 [英] Inner join on regexes

问题描述

我在正则表达式上有一个内部联接-这很慢.有什么简单的方法可以加快速度吗?我正在使用postgres.

I have an inner join on regular expressions - it is very slow. Is there any easy way to speed this up? I am using postgres.

FROM A
inner join B ON trim(lower(replace(replace(replace(B.enginequery,',',' '),'"',' '),'+',' '))) = trim(lower(A.keyphrase))
             OR trim(lower(replace(replace(replace(B.enginequery,',',' '),'"',' '),'+',' '))) ~ (trim(lower(A.keyphrase)) || '$')
             OR trim(lower(replace(replace(replace(B.enginequery,',',' '),'"',' '),'+',' '))) ~ (trim(lower(A.keyphrase)) || ' ')

推荐答案

有什么简单的方法可以加快速度吗?

Is there any easy way to speed this up?

性能受损的原因是为了进行匹配而必须执行的所有操作，更不用说正则表达式了.您需要简化关系，所以不需要执行这些操作.

The reason performance suffers is all the operations, let alone the regex, that have to be performed just to make a match. You need to simplify the relationship so these don't need to be performed.

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