# Elasticsearch | Very slow search **URL:** \ **Category:** Elasticsearch\ **Created:** [February 28, 2019, 3:11pm UTC](https://discuss.elastic.co/t/elasticsearch-very-slow-search/170368 "2019-02-28T15:11:13Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![Nikesh](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/nikesh/32/86579_2.png) [@Nikesh](https://discuss.elastic.co/u/Nikesh)\ **Post date:** [February 28, 2019, 3:11pm UTC](https://discuss.elastic.co/t/elasticsearch-very-slow-search/170368/1 "2019-02-28T15:11:13Z")
Hi, I am benchmarking search speed using different parameters. One specific parameter used is copy\_to implementation. Scenario 1. 1. Number of Fields : 10000 2. Documents indexed : 500 3. Indices : 10 4. Search on Indices : 10 at once Search Speed using copy\_to field: 20ms -3s Scenario 2. 1. Number of Fields : 10000 2. Documents indexed : 100000 3. Indices : 10 4. Search on Indices : 10 at once Search Speed using copy\_to field: 6s - 18s I suppose the number of documents stored in Elasticsearch will not affect the search speed. Also, since the use of copy\_to field, it will reduce the number of disk seeks during search to one field. Hence even this should not be something to worry about Why is there a drastic increase in search speed when number of documents increased? Am I missing something here? Because this is driving me crazy! ---
**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\ **Post date:** [February 28, 2019, 3:16pm UTC](https://discuss.elastic.co/t/elasticsearch-very-slow-search/170368/2 "2019-02-28T15:16:15Z")
What kind of searches are you running? ---
**Author:** ![Nikesh](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/nikesh/32/86579_2.png) [@Nikesh](https://discuss.elastic.co/u/Nikesh)\ **Post date:** [February 28, 2019, 3:17pm UTC](https://discuss.elastic.co/t/elasticsearch-very-slow-search/170368/3 "2019-02-28T15:17:18Z")
Multiple should clauses 1. Phrase match 2. Phrase with slop 3. Word based Fuzziness 4. Word based match ---
**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\ **Post date:** [February 28, 2019, 3:44pm UTC](https://discuss.elastic.co/t/elasticsearch-very-slow-search/170368/4 "2019-02-28T15:44:52Z")
Are you running these against the copy\_to field you mentioned? Can you show some examples? ---
**Author:** ![Nikesh](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/nikesh/32/86579_2.png) [@Nikesh](https://discuss.elastic.co/u/Nikesh)\ **Post date:** [February 28, 2019, 3:52pm UTC](https://discuss.elastic.co/t/elasticsearch-very-slow-search/170368/5 "2019-02-28T15:52:16Z")
yes, I am running these against copy\_to. The query contains 1. "query\_string\_query" for exact phrase match, 2. "multi\_match" for phrase with slop 3. "multi\_match" for word with fuzziness 4. "multi\_match" for word based match ---
**Author:** ![Nikesh](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/nikesh/32/86579_2.png) [@Nikesh](https://discuss.elastic.co/u/Nikesh)\ **Post date:** [March 4, 2019, 5:56am UTC](https://discuss.elastic.co/t/elasticsearch-very-slow-search/170368/6 "2019-03-04T05:56:22Z")
@Christian_Dahlqvist any suggestions? ---
**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\ **Post date:** [March 4, 2019, 6:45am UTC](https://discuss.elastic.co/t/elasticsearch-very-slow-search/170368/7 "2019-03-04T06:45:46Z")
Can you show some full example queries and how long they take to run? Why do you have so many fields in your index? ---
**Author:** ![Nikesh](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/nikesh/32/86579_2.png) [@Nikesh](https://discuss.elastic.co/u/Nikesh)\ **Post date:** [March 4, 2019, 7:38am UTC](https://discuss.elastic.co/t/elasticsearch-very-slow-search/170368/8 "2019-03-04T07:38:36Z")
Thanks Christian for quick response. Like I mentioned earlier, this is a benchmarking process. My query is something of this sort ``` { "query": { "bool": { "should": [ 1. Query String query of exact match 2. Multi_match of type phrase with slop of 1 3. Multi_match with fuzziness 4. Multi_match without fuzziness ], "minimum_should_match": 1 } } } ``` ---
**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\ **Post date:** [March 4, 2019, 8:45am UTC](https://discuss.elastic.co/t/elasticsearch-very-slow-search/170368/9 "2019-03-04T08:45:48Z")
That does not look like a valid query. Can you please show a full example? ---
**Author:** ![Nikesh](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/nikesh/32/86579_2.png) [@Nikesh](https://discuss.elastic.co/u/Nikesh)\ **Post date:** [March 4, 2019, 11:16am UTC](https://discuss.elastic.co/t/elasticsearch-very-slow-search/170368/10 "2019-03-04T11:16:10Z")
These four are the clauses of bool should query. ---
**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\ **Post date:** [March 4, 2019, 11:18am UTC](https://discuss.elastic.co/t/elasticsearch-very-slow-search/170368/11 "2019-03-04T11:18:12Z")
I give up. As you are not answering my questions I will leave this for someone else. ---
**Author:** ![dadoonet](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dadoonet/32/137187_2.png) [@dadoonet](https://discuss.elastic.co/u/dadoonet)\ **Post date:** [March 4, 2019, 11:38am UTC](https://discuss.elastic.co/t/elasticsearch-very-slow-search/170368/12 "2019-03-04T11:38:24Z")
As @Christian_Dahlqvist asked, you need to give **a real and complete example**. Not pseudo-code. Otherwise, there is no way to help you I'm afraid. ---
**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\ **Post date:** [March 5, 2019, 8:27am UTC](https://discuss.elastic.co/t/elasticsearch-very-slow-search/170368/13 "2019-03-05T08:27:28Z")
If you are using query string queries without specifying a field name, be aware that the old `_all` field has been replaced by an [all\_fields](https://www.elastic.co/guide/en/elasticsearch/reference/6.6/query-dsl-query-string-query.html) mode, which can be slow if you have a lot of fields it need to iterate over. Combine this with slop and fuzziness and you could have a very expensive (and slow) query. You may also want to look into creating a custom copy\_all field to use by default, much like the old \_all field worked. ---
**Author:** ![Nikesh](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/nikesh/32/86579_2.png) [@Nikesh](https://discuss.elastic.co/u/Nikesh)\ **Post date:** [March 5, 2019, 9:18am UTC](https://discuss.elastic.co/t/elasticsearch-very-slow-search/170368/14 "2019-03-05T09:18:42Z")
Thanks for your suggestion. I am using [copy\_to](https://www.elastic.co/guide/en/elasticsearch/reference/current/copy-to.html) field. ---
**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\ **Post date:** [March 5, 2019, 9:20am UTC](https://discuss.elastic.co/t/elasticsearch-very-slow-search/170368/15 "2019-03-05T09:20:38Z")
Then please provide detailed information, mappings and actual queries. Without that it is impossible to help. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [April 2, 2019, 9:26am UTC](https://discuss.elastic.co/t/elasticsearch-very-slow-search/170368/16 "2019-04-02T09:26:22Z")
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