Re^3: regexp performance on large logfiles

in reply to Re^2: regexp performance on large logfiles
in thread regexp performance on large logfiles

At least for those simplicistic patterns, you'll likely do much better if you just do a substring search. The regex engine will also do the substring search for you, but if you don't have www.*.info as valid pattern, using ~~substr~~ index could be faster. Even if you have such patterns, you can possibly move them towards the end of the checks so the rejection can happen earlier.

Update: I meant index...

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Re^4: regexp performance on large logfiles by snl_JYDawg (Initiate) on Aug 05, 2008 at 13:37 UTC
current runtime: 25,4 minutes. just by re-examining the patterns and use as much index and substr as possible.	[reply]
Re^4: regexp performance on large logfiles by ikegami (Patriarch) on Aug 05, 2008 at 17:47 UTC
Do you mean `index`? That shouldn't be any faster than a compiled regexp. The problem the OP has is that he's compiling his regexps over and over and over and over again.	[reply] [d/l]

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