# Excision is very slow for huge number of entities

**URL:** <https://forum.datomic.com/t/excision-is-very-slow-for-huge-number-of-entities/1874>\
**Category:** Datomic Pro\
**Created:** [June 16, 2021, 1:36pm UTC](https://forum.datomic.com/t/excision-is-very-slow-for-huge-number-of-entities/1874 "2021-06-16T13:36:53Z")\
**Posts on this page:** 1\
**Showing post:** 19

<div class="post-metadata">

**Author:** ![nikolayandr](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.datomic.com/nikolayandr/32/375_2.png) [@nikolayandr](https://forum.datomic.com/u/nikolayandr)\
**Post date:** [February 9, 2025, 9:09am UTC](https://forum.datomic.com/t/excision-is-very-slow-for-huge-number-of-entities/1874/19 "2025-02-09T09:09:41Z")

</div>

On the screen, you can see that 17592206943037 was excised(the left window proves that excision was executed),

 ![image](https://us1.discourse-cdn.com/flex016/uploads/cognitect/original/1X/976126781781f4d703c76acfe399c9bda72ffd15.png)  
but I can still find data in the history db(the right window on the screen), whereas [Excision | Datomic](https://docs.datomic.com/operation/excision.html#tracking-excisions) states: `Excision is lossy. Given a datom, you cannot ask "Was this datom in the database before an excision?" If you could ask that question, then the datom is still present in some sense, which defeats the purpose of excision.`

P.S. Sync excise, GC storage, and Postgres full vacuum were executed before I did the screenshot

---

_[View the full topic](https://forum.datomic.com/t/excision-is-very-slow-for-huge-number-of-entities/1874)._