# How elasticsearch supports regex search and its performance
**URL:** https://discuss.elastic.co/t/how-elasticsearch-supports-regex-search-and-its-performance/12033
**Category:** Elasticsearch
**Created:** [May 20, 2013, 6:22am UTC](https://discuss.elastic.co/t/how-elasticsearch-supports-regex-search-and-its-performance/12033 "2013-05-20T06:22:51Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Wenbin\_Li](https://discuss.elastic.co/u/Wenbin_Li)
#### Post date: [May 20, 2013, 6:22am UTC](https://discuss.elastic.co/t/how-elasticsearch-supports-regex-search-and-its-performance/12033/1 "2013-05-20T06:22:51Z")
Hi,
I want to use elasticsearch to index large amount log data and search using
regex.
So I want to know how elasticsearch support the regex search for millions
of raw data.
I think it could not be matching all the records one by one for the
performance, so is there any information for this question?
Thanks for any suggestion.
-Wenbin
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### Author:  [@Boaz\_Leskes](https://discuss.elastic.co/u/Boaz_Leskes)
#### Post date: [May 22, 2013, 1:19pm UTC](https://discuss.elastic.co/t/how-elasticsearch-supports-regex-search-and-its-performance/12033/2 "2013-05-22T13:19:48Z")
Hi Wenbin,
Elasticsearch uses lucene's RegexpQuery for this. As of version 0.90 of ES
(using Lucene 4.3) it is executed using an constructed automaton which
makes it much faster. You can read more here:
> **[Lucene's FuzzyQuery is 100 times faster in 4.0](https://blog.mikemccandless.com/2011/03/lucenes-fuzzyquery-is-100-times-faster.html)**
>
> There are many exciting improvements in Lucene's eventual 4.0 (trunk) release, but the awesome speedup to FuzzyQuery really stands out, not...
or
[http://lucene.apache.org/core/4\_2\_0/core/org/apache/lucene/search/RegexpQuery.html](http://lucene.apache.org/core/4_2_0/core/org/apache/lucene/search/RegexpQuery.html)
Cheers,
Boaz
On Monday, May 20, 2013 8:22:51 AM UTC+2, Wenbin Li wrote:
> Hi,
>
> I want to use elasticsearch to index large amount log data and search
> using regex.
> So I want to know how elasticsearch support the regex search for millions
> of raw data.
> I think it could not be matching all the records one by one for the
> performance, so is there any information for this question?
>
> Thanks for any suggestion.
> -Wenbin
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### Author:  [@Clinton\_Gormley](https://discuss.elastic.co/u/Clinton_Gormley)
#### Post date: [May 23, 2013, 10:31am UTC](https://discuss.elastic.co/t/how-elasticsearch-supports-regex-search-and-its-performance/12033/3 "2013-05-23T10:31:35Z")
Hi Wenbin
Note that the performance of regexes drops off rapidly the shorter the
prefix.
So "foobar.\*" will be fast, but ".\*foobar" won't...
clint
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 6, 2017, 2:35am UTC](https://discuss.elastic.co/t/how-elasticsearch-supports-regex-search-and-its-performance/12033/4 "2017-07-06T02:35:09Z")