Why is RAM not released after mysqldump?

Question

MySQL

Mysqldump does not release RAM. Tell me, please, what could be the reason?
I run the command like this:

mysqldump --opt -uroot -ppass dbname| gzip > /backup/backup-date +%d-%m-%y.gz

Answer 1

after the start of activity, the normal behavior of the database server is not to give memory immediately, but to wait for further loading. if it is not there, the memory is given after a certain time interval for
more details about the strategy of a particular DBMS and settings options - in the documentation of this DBMS

Answer 2

What kind of memory does this graph show? There is a suspicion that Used, but it also includes a file cache.

Answer 3

What does mysqldump have to do with it? Because the first in a row in the team goes? Here is the most resource intensive gzip application. There are monitoring utilities (top, htop, a whole legion of them) that will show which process is consuming memory.