# Aggregations Parallelism Level **URL:** \ **Category:** Elasticsearch\ **Created:** [December 26, 2014, 4:14pm UTC](https://discuss.elastic.co/t/aggregations-parallelism-level/21399 "2014-12-26T16:14:11Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![roytmana](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/roytmana/32/44855_2.png) [@roytmana](https://discuss.elastic.co/u/roytmana)\ **Post date:** [December 26, 2014, 4:14pm UTC](https://discuss.elastic.co/t/aggregations-parallelism-level/21399/1 "2014-12-26T16:14:11Z")
Hi, What's the level of parallelism when aggregations are calculated? Is it thread per shard? In this case I assume a node hosting one index should have have roughly one shard per server core? Is it the same for searching or lucene supports parallel search on the same index (ES shard) Thanks Alex -- 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). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/b44c62d4-519e-4e3b-9b5c-ea95854fdf2f%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/b44c62d4-519e-4e3b-9b5c-ea95854fdf2f%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**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, 12:41am UTC](https://discuss.elastic.co/t/aggregations-parallelism-level/21399/2 "2017-07-06T00:41:53Z")
Closed on July 6, 2017, 12:41am UTC