Jester memory usage keep rising using sqlite

[me7]

My testing jester app memory keep rising. when start res mem around 2MB then go 
up to 12MB with about 50 load. I want to ask for how to use db_sqlite 
correctly? right now I'm just open in the beginning but no close (not know 
where to close) do I need to do db.close in every route?

import jester

let db = open("chinook.db","","","")

routes:
    

get "/":
    var s = "header <br>"

for x in db.fastRows sql"select * from albums;":
    s.add "album " & $x & "<br>"

s.add "footer" resp s