v6.35.4 used all RAM memory

Hello!
I have Dude 6.35.4 + RouterOS-x86 on server 4 core CPU, 2Gb RAM, Dude-db have size 350Mb.
When I turn on the server used RAM memory 1,2Gb, after 4 months used RAM volume increases to 1,7Gb.

When i do:
/dude export-db backup-file=backup_db
the amount of used RAM memory consumed is reduced to 1,2Gb

Why is this happening? Why does the consumption of RAM increase?

Just guess - caching? When the data is reorganised due to dude stop and start, the cache in memory shrinks too… Maybe.

Thanks for the answer. The problem is that if this is a cache, then it can occupy all the RAM and the server will hang.
Can I somehow control or disable caching?

If it is a cache it could be limited autonomously by the dude application according to the free amount of ram.