# Memtable and cache behavior

**URL:** <https://forum.scylladb.com/t/memtable-and-cache-behavior/5194>\
**Category:** ScyllaDB\
**Tags:** cache, architecture, memory\
**Created:** [November 30, 2025, 8:13am UTC](https://forum.scylladb.com/t/memtable-and-cache-behavior/5194 "2025-11-30T08:13:30Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Guy](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.scylladb.com/guy/32/9_2.png) [@Guy](https://forum.scylladb.com/u/Guy)\
**Post date:** [November 30, 2025, 8:13am UTC](https://forum.scylladb.com/t/memtable-and-cache-behavior/5194/1 "2025-11-30T08:13:30Z")

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> [@](#):
>
> **[Originally from the User Slack](https://scylladb-users.slack.com/)**
> 
> ![Mahdi_Kamali](https://us1.discourse-cdn.com/flex016/uploads/scylladb/original/2X/7/7fb1a0a118e8eb1518763300c376e9c0ce9db7bc.png) @Mahdi\_KamaliMahdi\_KamaliMahdi\_KamaliMahdi\_Kamali\*\*:\*\* When a memtable is being flushed, while some rows have been updated, what happens to those rows in cache? When rows in cache will be invalidated and when will be merged?
> 
> ![avi](https://us1.discourse-cdn.com/flex016/uploads/scylladb/original/1X/b5e08becda8d9df1abff1d3a2d9ffe1126ac3fc6.jpeg) @avi\*\*:\*\* If the partition exists in cache, rows in the memtable being flushed will be merged into cache