# What does Setrefresh do while index a document? **URL:** \ **Category:** Elasticsearch\ **Created:** [June 5, 2013, 12:34pm UTC](https://discuss.elastic.co/t/what-does-setrefresh-do-while-index-a-document/12277 "2013-06-05T12:34:59Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Arjit\_Gupta](https://avatars.discourse-cdn.com/v4/letter/a/e9bcb4/32.png) [@Arjit\_Gupta](https://discuss.elastic.co/u/Arjit_Gupta)\ **Post date:** [June 5, 2013, 12:34pm UTC](https://discuss.elastic.co/t/what-does-setrefresh-do-while-index-a-document/12277/1 "2013-06-05T12:34:59Z")
Hi, I am new to elastic search. I just want to know what does setrefresh do ? from the docs [http://www.elasticsearch.org/guide/reference/api/index\_/](http://www.elasticsearch.org/guide/reference/api/index_/) It says it makes it available to search. I am interested in knowing some internals to how does refresh happen ? Does it refreshes the whole cache ? Or only merges the segments which contains the document. Does setrefersh effects "other" documents also ? -- 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:** ![Arjit\_Gupta](https://avatars.discourse-cdn.com/v4/letter/a/e9bcb4/32.png) [@Arjit\_Gupta](https://discuss.elastic.co/u/Arjit_Gupta)\ **Post date:** [June 6, 2013, 1:20am UTC](https://discuss.elastic.co/t/what-does-setrefresh-do-while-index-a-document/12277/2 "2013-06-06T01:20:08Z")
Any one ? On Wednesday, June 5, 2013 6:04:59 PM UTC+5:30, Arjit Gupta wrote: > Hi, > > I am new to Elasticsearch. I just want to know what does setrefresh do ? > from the docs > [Elasticsearch Platform — Find real-time answers at scale | Elastic](http://www.elasticsearch.org/guide/reference/api/index_/) > It says it makes it available to search. > I am interested in knowing some internals to how does refresh happen ? > Does it refreshes the whole cache ? Or only merges the segments which > contains the document. > Does setrefersh effects "other" documents also ? -- 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:** ![spinscale](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/spinscale/32/25011_2.png) [@spinscale](https://discuss.elastic.co/u/spinscale)\ **Post date:** [June 6, 2013, 8:25am UTC](https://discuss.elastic.co/t/what-does-setrefresh-do-while-index-a-document/12277/3 "2013-06-06T08:25:22Z")
Hey refreshing is an expensive operation, which makes data, that has been recently indexed, available for searching. Because it is that expensive, a refresh is executed once per second in the background instead of every indexing operation. Refresh does not refresh a cache. Refresh does not do a merge. Refresh affects all documents, which have been indexed since the last refresh. So what does it do? In order to understand this, you need to know, that a lucene index reader (which is used for searches at the end) is always a snapshot of data at a certain time. In order to search in recently indexed documents, you need move the point in time and index reader can read from, to a newer point. And this is exactly what the refresh call is doing. Hope this helps a bit. --Alex On Thu, Jun 6, 2013 at 3:20 AM, Arjit Gupta [arjit292@gmail.com](mailto:arjit292@gmail.com) wrote: > Any one ? > > On Wednesday, June 5, 2013 6:04:59 PM UTC+5:30, Arjit Gupta wrote: > > > Hi, > > > > I am new to Elasticsearch. I just want to know what does setrefresh do ? > > from the docs > > [Elasticsearch Platform — Find real-time answers at scale | Elastic](http://www.elasticsearch.org/**guide/reference/api/index_/)[http://www.elasticsearch.org/guide/reference/api/index\_/](http://www.elasticsearch.org/guide/reference/api/index_/) > > It says it makes it available to search. > > I am interested in knowing some internals to how does refresh happen ? > > Does it refreshes the whole cache ? Or only merges the segments which > > contains the document. > > Does setrefersh effects "other" documents also ? > > > > -- > > 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:** ![a1senfter](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/a1senfter/32/3998_2.png) [@a1senfter](https://discuss.elastic.co/u/a1senfter)\ **Post date:** [August 3, 2015, 3:26pm UTC](https://discuss.elastic.co/t/what-does-setrefresh-do-while-index-a-document/12277/4 "2015-08-03T15:26:24Z")
Hi to all, thanks Alexander for your explanation. But I've an additional question when using the bulk index/update call via node-client with enabled refresh option in elasticsearch version 1.5.2. Is it guaranteed that the IndexReader is updated during the _bulkRequest.execute().actionGet()_ method call, so that all new or updated docs are searchable directly afterwards? ---
**Author:** ![a1senfter](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/a1senfter/32/3998_2.png) [@a1senfter](https://discuss.elastic.co/u/a1senfter)\ **Post date:** [August 25, 2015, 7:52am UTC](https://discuss.elastic.co/t/what-does-setrefresh-do-while-index-a-document/12277/5 "2015-08-25T07:52:50Z")
Has anyone a hint for me? ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 5, 2017, 11:54pm UTC](https://discuss.elastic.co/t/what-does-setrefresh-do-while-index-a-document/12277/6 "2017-07-05T23:54:02Z")