# Update by query with index alias **URL:** \ **Category:** Elasticsearch\ **Created:** [March 2, 2022, 11:21am UTC](https://discuss.elastic.co/t/update-by-query-with-index-alias/298610 "2022-03-02T11:21:36Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Metheny](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/metheny/32/102517_2.png) [@Metheny](https://discuss.elastic.co/u/Metheny)\ **Post date:** [March 2, 2022, 11:21am UTC](https://discuss.elastic.co/t/update-by-query-with-index-alias/298610/1 "2022-03-02T11:21:36Z")
In the [Alias documentation](https://www.elastic.co/guide/en/elasticsearch/reference/8.0/aliases.html) it says that write operations aren't allowed on index alias and that it would return an error: > If an alias points to multiple indices or data streams and is\_write\_index isn’t set, the alias rejects write requests. However in the [update by query documentation](https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-update-by-query.html#docs-update-by-query-api-path-params) it says: > (Optional, string) Comma-separated list of data streams, indices, and aliases to search. Supports wildcards (\*). To search all data streams or indices, omit this parameter or use \* or \_all. Failure may be true for example for updating a single doc by id, but an `_update_by_query` succeeds when run on an index alias. So am I missing anything or is the Alias documentation not accurate? ---
**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 2, 2022, 1:58pm UTC](https://discuss.elastic.co/t/update-by-query-with-index-alias/298610/2 "2022-03-02T13:58:17Z")
It is correct as update by query first runs a query to identify which documents are to be updated (and indices these are located in) before updating these directly using the appropriate index, not the alias. ---
**Author:** ![Metheny](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/metheny/32/102517_2.png) [@Metheny](https://discuss.elastic.co/u/Metheny)\ **Post date:** [March 2, 2022, 2:03pm UTC](https://discuss.elastic.co/t/update-by-query-with-index-alias/298610/3 "2022-03-02T14:03:00Z")
I see, but it's a bit misleading, since as far as the end user, both of these are considered write operations using an alias: `POST alias/_update/5` `POST alias/_update_by_query` The way that Elasticsearch handles it behind the scene may be different as you say, but the Alias docs saying that using the alias for write operations will fail as a whole is misleading, and I think that part needs to be revised. ---
**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\ **Post date:** [March 2, 2022, 11:09pm UTC](https://discuss.elastic.co/t/update-by-query-with-index-alias/298610/4 "2022-03-02T23:09:09Z")
You'd be best off raising an issue on GitHub to have it addressed 🙂 > **[Issues · elastic/elasticsearch](https://github.com/elastic/elasticsearch/issues/)** > > Free and Open, Distributed, RESTful Search Engine. Contribute to elastic/elasticsearch development by creating an account on GitHub. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [March 30, 2022, 11:09pm UTC](https://discuss.elastic.co/t/update-by-query-with-index-alias/298610/5 "2022-03-30T23:09:46Z")
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