# Algorithm complexity **URL:** \ **Category:** Elasticsearch\ **Created:** [June 7, 2013, 11:16pm UTC](https://discuss.elastic.co/t/algorithm-complexity/12323 "2013-06-07T23:16:12Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![irfan\_mir](https://avatars.discourse-cdn.com/v4/letter/i/278dde/32.png) [@irfan\_mir](https://discuss.elastic.co/u/irfan_mir)\ **Post date:** [June 7, 2013, 11:16pm UTC](https://discuss.elastic.co/t/algorithm-complexity/12323/1 "2013-06-07T23:16:12Z")
What is the Algorithm (time) complexity of the search function / algorithm in Elastic Search? I was just wondering for my information. Is there a place where I can find this and other facts about Elastic Search ? -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). ---
**Author:** ![vineeth\_mohan](https://avatars.discourse-cdn.com/v4/letter/v/bc79bd/32.png) [@vineeth\_mohan](https://discuss.elastic.co/u/vineeth_mohan)\ **Post date:** [June 8, 2013, 2:00am UTC](https://discuss.elastic.co/t/algorithm-complexity/12323/2 "2013-06-08T02:00:17Z")
First of all something like a hash table or a reverse index ( in simple words) powers the search of ES. Lucene library does this part. So theoretically , the search complexity should be O(1). Thanks Vineeth On Sat, Jun 8, 2013 at 4:46 AM, irfan mir [theirf@gmail.com](mailto:theirf@gmail.com) wrote: > What is the Algorithm (time) complexity of the search function / algorithm > in Elastic Search? I was just wondering for my information. > > Is there a place where I can find this and other facts about Elastic > Search ? > > -- > You received this message because you are subscribed to the Google Groups > "elasticsearch" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). > For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). ---
**Author:** ![irfan\_mir](https://avatars.discourse-cdn.com/v4/letter/i/278dde/32.png) [@irfan\_mir](https://discuss.elastic.co/u/irfan_mir)\ **Post date:** [June 8, 2013, 4:51am UTC](https://discuss.elastic.co/t/algorithm-complexity/12323/3 "2013-06-08T04:51:10Z")
I know it is lucene. But is it a hash table or reverse index? On Jun 7, 2013 9:00 PM, "Vineeth Mohan" [vineethmohan@algotree.com](mailto:vineethmohan@algotree.com) wrote: > First of all something like a hash table or a reverse index ( in simple > words) powers the search of ES. > Lucene library does this part. > So theoretically , the search complexity should be O(1). > > Thanks > Vineeth > > On Sat, Jun 8, 2013 at 4:46 AM, irfan mir [theirf@gmail.com](mailto:theirf@gmail.com) wrote: > > > What is the Algorithm (time) complexity of the search function / > > algorithm in Elastic Search? I was just wondering for my information. > > > > Is there a place where I can find this and other facts about Elastic > > Search ? > > > > -- > > You received this message because you are subscribed to the Google Groups > > "elasticsearch" group. > > To unsubscribe from this group and stop receiving emails from it, send an > > email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). > > For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). > > -- > You received this message because you are subscribed to a topic in the > Google Groups "elasticsearch" group. > To unsubscribe from this topic, visit > [https://groups.google.com/d/topic/elasticsearch/IslO45DYgqc/unsubscribe?hl=en-US](https://groups.google.com/d/topic/elasticsearch/IslO45DYgqc/unsubscribe?hl=en-US) > . > To unsubscribe from this group and all its topics, send an email to > [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). > For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 2:32am UTC](https://discuss.elastic.co/t/algorithm-complexity/12323/4 "2017-07-06T02:32:14Z")