# Reindex api using a query and size **URL:** \ **Category:** Elasticsearch\ **Created:** [May 31, 2016, 8:11pm UTC](https://discuss.elastic.co/t/reindex-api-using-a-query-and-size/51481 "2016-05-31T20:11:28Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![marinoc](https://avatars.discourse-cdn.com/v4/letter/m/87869e/32.png) [@marinoc](https://discuss.elastic.co/u/marinoc)\ **Post date:** [May 31, 2016, 8:11pm UTC](https://discuss.elastic.co/t/reindex-api-using-a-query-and-size/51481/1 "2016-05-31T20:11:28Z")
I have an index w 120 mil records (each record ~ 5k), and I want to use the Reindex api to create a new index w a subset of those records. I've identified a subset of records (about 2 million) from a query and would like to use this query in the Reindex api call. Is it best practice to move all records in a single command, or do I need to do some type of batching or throttling? I know there's a size parameter w the reindex api. If I set it to 10,000, will it move all 2 million records to the new index in batches of 10,000? Or just the first 10,000 records? Thanks! ---
**Author:** ![dakrone](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dakrone/32/23351_2.png) [@dakrone](https://discuss.elastic.co/u/dakrone)\ **Post date:** [May 31, 2016, 8:54pm UTC](https://discuss.elastic.co/t/reindex-api-using-a-query-and-size/51481/2 "2016-05-31T20:54:47Z")
So you certainly can do the entire thing with a single request, however, if you want to have throttling (to lessen the impact of the reindexing), you will have to wait until 2.4.0 (see: [https://github.com/elastic/elasticsearch/pull/18020](https://github.com/elastic/elasticsearch/pull/18020)). You could do a subset with `size`, but there isn't an offset/from option, so you wouldn't be able to do a different "batch" of documents, you'd have to limit it artificially using the query somehow. ---
**Author:** ![marinoc](https://avatars.discourse-cdn.com/v4/letter/m/87869e/32.png) [@marinoc](https://discuss.elastic.co/u/marinoc)\ **Post date:** [May 31, 2016, 9:05pm UTC](https://discuss.elastic.co/t/reindex-api-using-a-query-and-size/51481/3 "2016-05-31T21:05:33Z")
Thanks! ---
**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, 10:47pm UTC](https://discuss.elastic.co/t/reindex-api-using-a-query-and-size/51481/4 "2017-07-05T22:47:31Z")