# Another "indexing \_ids in 0.16" question set **URL:** \ **Category:** Elasticsearch\ **Created:** [June 3, 2011, 10:45pm UTC](https://discuss.elastic.co/t/another-indexing--ids-in-0-16-question-set/4546 "2011-06-03T22:45:14Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Alex\_At\_Ikanow](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/alex_at_ikanow/32/676_2.png) [@Alex\_At\_Ikanow](https://discuss.elastic.co/u/Alex_At_Ikanow)\ **Post date:** [June 3, 2011, 10:45pm UTC](https://discuss.elastic.co/t/another-indexing--ids-in-0-16-question-set/4546/1 "2011-06-03T22:45:14Z")
I didn't see this discussed in any of the previous threads on this topic, apologies if I've missed it. I have a large index with two types: "parent" and "child", where "child" is obviously a child of "parent" (ie I used "has\_child" queries). I have many children per parent. I set the "_id" to be of the format "\_", for reasons discussed below. I don't know if this was sensible, but I now have a large index of such objects, so probably doing anything else at this point is difficult (though I suppose possible). In 0.15 I deleted a parent's children from the parent's "\_id" using a prefix query, based on the above format. This had the advantage of not needing to know anything else about the parent (eg the number of children that it has) In 0.16 this is no longer possible. I can't easily use the ids query because I don't always know how many children the parent has. So four questions: 0] Is there a standard way of deleting all children of a parent, given only that parent's \_id, and I've just missed it and it will magically solve all my problems?! (If so, ignore all these other questions! Though [1] may be a bug?) 1] Interestingly when I first upgraded to 0.16.2 (from the last 0.15 branch) all documents still had their \_ids indexed (eg a prefix query on \_id would work). I thought the default was to lose the indexing immediately? When I added a new document, its \_id field was not indexed (ie as expected). 2] I hoped that setting the mapping for the child type to include \_id: { index: not\_analyzed } at the top level would update the mapping dynamically, but this did not happen. When I created a new type (for an existing index) with the same mapping, this did start indexing \_ids. Is this expected? (ie that the \_id mapping only gets applied to new indexes and doesn't get merged) 3] I don't want to set the "index.mapping.\_id.indexed"="true" at the node level, because I have lots of other objects whose \_ids I don't need to index. Can I set this for just a single index/type pair? Note that I set up all my indexes and types programmatically from Java (using gson), ie the mapping information is not encoded in any configuration files. Thanks in advance to anyone for any thoughts! Alex ---
**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:** [June 3, 2011, 11:19pm UTC](https://discuss.elastic.co/t/another-indexing--ids-in-0-16-question-set/4546/2 "2011-06-03T23:19:46Z")
When you index a child document, a field called \_parent is added to it with the parent UID. The \_parent field is in the form of parent\_type#parent\_id (text form). So, you can delete based on that. If that answer does not answer the rest of the questions, ask, I might have missed something. On Saturday, June 4, 2011 at 1:45 AM, Alex at Ikanow wrote: > I didn't see this discussed in any of the previous threads on this > topic, apologies if I've missed it. > > I have a large index with two types: "parent" and "child", where > "child" is obviously a child of "parent" (ie I used "has\_child" > queries). I have many children per parent. > > I set the "_id" to be of the format "\_", for reasons > discussed below. I don't know if this was sensible, but I now have a > large index of such objects, so probably doing anything else at this > point is difficult (though I suppose possible). > > In 0.15 I deleted a parent's children from the parent's "\_id" using a > prefix query, based on the above format. This had the advantage of not > needing to know anything else about the parent (eg the number of > children that it has) > > In 0.16 this is no longer possible. I can't easily use the ids query > because I don't always know how many children the parent has. > > So four questions: > > 0] Is there a standard way of deleting all children of a parent, given > only that parent's \_id, and I've just missed it and it will magically > solve all my problems?! > > (If so, ignore all these other questions! Though [1] may be a bug?) > > 1] Interestingly when I first upgraded to 0.16.2 (from the last 0.15 > branch) all documents still had their \_ids indexed (eg a prefix query > on \_id would work). I thought the default was to lose the indexing > immediately? > > When I added a new document, its \_id field was not indexed (ie as > expected). > > 2] I hoped that setting the mapping for the child type to include \_id: > { index: not\_analyzed } at the top level would update the mapping > dynamically, but this did not happen. When I created a new type (for > an existing index) with the same mapping, this did start indexing > \_ids. Is this expected? (ie that the \_id mapping only gets applied to > new indexes and doesn't get merged) > > 3] I don't want to set the "index.mapping.\_id.indexed"="true" at the > node level, because I have lots of other objects whose \_ids I don't > need to index. Can I set this for just a single index/type pair? Note > that I set up all my indexes and types programmatically from Java > (using gson), ie the mapping information is not encoded in any > configuration files. > > Thanks in advance to anyone for any thoughts! > > Alex ---
**Author:** ![Alex\_At\_Ikanow](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/alex_at_ikanow/32/676_2.png) [@Alex\_At\_Ikanow](https://discuss.elastic.co/u/Alex_At_Ikanow)\ **Post date:** [June 4, 2011, 3:01am UTC](https://discuss.elastic.co/t/another-indexing--ids-in-0-16-question-set/4546/3 "2011-06-04T03:01:58Z")
Thanks - just tried that and (of course) it solves my problem. The only other noteworthy thing was that when I migrated from 0.15.2(?) to 0.16.2, all the existing documents still had "\_id" indexed - is that the intended functionality? I'm mainly interested out of curiosity. On Jun 3, 7:19 pm, Shay Banon [shay.ba...@elasticsearch.com](mailto:shay.ba...@elasticsearch.com) wrote: > When you index a child document, a field called \_parent is added to it with the parent UID. The \_parent field is in the form of parent\_type#parent\_id (text form). So, you can delete based on that. If that answer does not answer the rest of the questions, ask, I might have missed something. ---
**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:** [June 4, 2011, 9:42pm UTC](https://discuss.elastic.co/t/another-indexing--ids-in-0-16-question-set/4546/4 "2011-06-04T21:42:55Z")
The \_id field will not be removed from existing documents, it will simply not be indexed for new documents (unless you set the relevant backward comp. flag). On Saturday, June 4, 2011 at 6:01 AM, Alex at Ikanow wrote: > Thanks - just tried that and (of course) it solves my problem. > > The only other noteworthy thing was that when I migrated from > 0.15.2(?) to 0.16.2, all the existing documents still had "\_id" > indexed - is that the intended functionality? I'm mainly interested > out of curiosity. > > On Jun 3, 7:19 pm, Shay Banon \<[shay.ba...@elasticsearch.com](mailto:shay.ba...@elasticsearch.com) ([http://elasticsearch.com](http://elasticsearch.com))\> wrote: > > > When you index a child document, a field called \_parent is added to it with the parent UID. The \_parent field is in the form of parent\_type#parent\_id (text form). So, you can delete based on that. If that answer does not answer the rest of the questions, ask, I might have missed something. ---
**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, 4:04am UTC](https://discuss.elastic.co/t/another-indexing--ids-in-0-16-question-set/4546/5 "2017-07-06T04:04:32Z")