# Stored Fields (by default)? **URL:** \ **Category:** Elasticsearch\ **Created:** [September 19, 2011, 1:11pm UTC](https://discuss.elastic.co/t/stored-fields-by-default/5407 "2011-09-19T13:11:18Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![davrob](https://avatars.discourse-cdn.com/v4/letter/d/d78d45/32.png) [@davrob](https://discuss.elastic.co/u/davrob)\ **Post date:** [September 19, 2011, 1:11pm UTC](https://discuss.elastic.co/t/stored-fields-by-default/5407/1 "2011-09-19T13:11:18Z")
Hi, For the purpose of performance (serverside and browser side) I'm limiting the number of fields returned, by using SearchRequestBuilder.addFields(), I then return results in the results using SearchHit.field(). The strange thing is that most of my fields are being returned even though I haven't marked them as "stored":true in my explicit mapping. Are some fields stored by default, the docs seem to suggest not [http://www.elasticsearch.org/guide/reference/mapping/core-types.html](http://www.elasticsearch.org/guide/reference/mapping/core-types.html) ? Currently, I'm going through my list of fields one-by-one, seeing if it gets returned by SearchHit.field(), and will try putting "stored":true explicitly on these fields, to see if they suddenly get returned by the call. Best Regards, David. ---
**Author:** ![Benjamin\_Deveze](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/benjamin_deveze/32/1577_2.png) [@Benjamin\_Deveze](https://discuss.elastic.co/u/Benjamin_Deveze)\ **Post date:** [September 19, 2011, 1:18pm UTC](https://discuss.elastic.co/t/stored-fields-by-default/5407/2 "2011-09-19T13:18:47Z")
Do you have \_source enabled (it is enabled by default)? Fields content can be retrieved from \_source even if the field itself is not stored. ---
**Author:** ![davrob](https://avatars.discourse-cdn.com/v4/letter/d/d78d45/32.png) [@davrob](https://discuss.elastic.co/u/davrob)\ **Post date:** [September 19, 2011, 2:32pm UTC](https://discuss.elastic.co/t/stored-fields-by-default/5407/3 "2011-09-19T14:32:18Z")
Hi Benjamin, Yes I do have source by default, but for performance reason I don't want to get source and parse the fields. -David. On Sep 19, 2:18 pm, Benjamin Devèze [benjamin.dev...@gmail.com](mailto:benjamin.dev...@gmail.com) wrote: > Do you have \_source enabled (it is enabled by default)? Fields content can > be retrieved from \_source even if the field itself is not stored. ---
**Author:** ![Clinton\_Gormley](https://avatars.discourse-cdn.com/v4/letter/c/50afbb/32.png) [@Clinton\_Gormley](https://discuss.elastic.co/u/Clinton_Gormley)\ **Post date:** [September 19, 2011, 3:09pm UTC](https://discuss.elastic.co/t/stored-fields-by-default/5407/4 "2011-09-19T15:09:05Z")
Hi David > Yes I do have source by default, but for performance reason I don't > want to get source and parse the fields. This is usually a false economy. Lucene needs to do a disk seek for each field that it returns, as opposed to just one for the \_source field. Usually the only time it makes sense to use separately stored fields instead of the \_source is when you have very large docs, and you only want (eg) a last\_modified date out of your doc. clint ---
**Author:** ![davrob](https://avatars.discourse-cdn.com/v4/letter/d/d78d45/32.png) [@davrob](https://discuss.elastic.co/u/davrob)\ **Post date:** [September 19, 2011, 5:09pm UTC](https://discuss.elastic.co/t/stored-fields-by-default/5407/5 "2011-09-19T17:09:57Z")
Hi Clint, That's interesting, I had assumed from this post [http://elasticsearch-users.115913.n3.nabble.com/profiling-shows-large-cpu-usage-for-scripts-tp2937899p2939235.html](http://elasticsearch-users.115913.n3.nabble.com/profiling-shows-large-cpu-usage-for-scripts-tp2937899p2939235.html) that if I was needing about 20 columns, out of the 70 or so I have indexed I should use the field value, certainly when I only need to return 5 or so fields I find the time to query is reduced by about half. In this case, 20 or so fields, I'm in two minds, whether to get the \_source and return it more-or-less as it is to the browser. Or whether to parse the source into a smaller dataset, giving the browser less to parse and reducing network time. thanks for you insight about the disk seek. -David. On Sep 19, 4:09 pm, Clinton Gormley [cl...@traveljury.com](mailto:cl...@traveljury.com) wrote: > Hi David > > > Yes I do have source by default, but for performance reason I don't > > want to get source and parse the fields. > > This is usually a false economy. Lucene needs to do a disk seek for each > field that it returns, as opposed to just one for the \_source field. > > Usually the only time it makes sense to use separately stored fields > instead of the \_source is when you have very large docs, and you only > want (eg) a last\_modified date out of your doc. > > clint ---
**Author:** ![kimchy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/kimchy/32/44952_2.png) [@kimchy](https://discuss.elastic.co/u/kimchy)\ **Post date:** [September 20, 2011, 8:27am UTC](https://discuss.elastic.co/t/stored-fields-by-default/5407/6 "2011-09-20T08:27:05Z")
From the other thread, the fact that something takes 30% cpu out of the execution time does not reflect if its slow or not :). 30% time taken from 20ms is not that much, for example ;). As clinton said, most times, it makes sense to just get the \_source, with the exception of very large single fields. Assuming you have no stored fields, then asking for specific fields will cause them to be parsed and extracted from the source. This will cause the source to be parsed and for the fields to be extracted. On the other hand, if you just ask for the \_source, it will be loaded and returned as is all the way back. On Mon, Sep 19, 2011 at 8:09 PM, davrob2 [daviroberts@gmail.com](mailto:daviroberts@gmail.com) wrote: > Hi Clint, > > That's interesting, I had assumed from this post > > [http://elasticsearch-users.115913.n3.nabble.com/profiling-shows-large-cpu-usage-for-scripts-tp2937899p2939235.html](http://elasticsearch-users.115913.n3.nabble.com/profiling-shows-large-cpu-usage-for-scripts-tp2937899p2939235.html) > that if I was needing about 20 columns, out of the 70 or so I have > indexed I should use the field value, certainly when I only need to > return 5 or so fields I find the time to query is reduced by about > half. > > In this case, 20 or so fields, I'm in two minds, whether to get the > \_source and return it more-or-less as it is to the browser. Or > whether to parse the source into a smaller dataset, giving the browser > less to parse and reducing network time. > > thanks for you insight about the disk seek. > > -David. > > On Sep 19, 4:09 pm, Clinton Gormley [cl...@traveljury.com](mailto:cl...@traveljury.com) wrote: > > > Hi David > > > > > Yes I do have source by default, but for performance reason I don't > > > want to get source and parse the fields. > > > > This is usually a false economy. Lucene needs to do a disk seek for each > > field that it returns, as opposed to just one for the \_source field. > > > > Usually the only time it makes sense to use separately stored fields > > instead of the \_source is when you have very large docs, and you only > > want (eg) a last\_modified date out of your doc. > > > > clint ---
**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, 3:54am UTC](https://discuss.elastic.co/t/stored-fields-by-default/5407/7 "2017-07-06T03:54:06Z")