[Nitrado]

ClickHouse ships with a command line tool which does this (without the actual database server):

    ps aux | tail -n +2 | awk '{ printf("%s\t%s\n", $1, $4) }' | \
        clickhouse-local -S "user String, mem Float64" \
            -q "SELECT user, round(sum(mem), 2) as memTotal FROM table GROUP BY user ORDER BY memTotal DESC FORMAT Pretty"

    
    ┏━━━━━━━━━━┳━━━━━━━━━━┓
    ┃ user     ┃ memTotal ┃
    ┡━━━━━━━━━━╇━━━━━━━━━━┩
    │ clickho+ │      0.7 │
    ├──────────┼──────────┤
    │ root     │      0.2 │
    ├──────────┼──────────┤
    │ netdata  │      0.1 │
    ├──────────┼──────────┤
    │ ntp      │        0 │
    ├──────────┼──────────┤
    │ dbus     │        0 │
    ├──────────┼──────────┤
    │ nginx    │        0 │
    ├──────────┼──────────┤
    │ polkitd  │        0 │
    ├──────────┼──────────┤
    │ nscd     │        0 │
    ├──────────┼──────────┤
    │ postfix  │        0 │
    └──────────┴──────────┘

Has the advantage of being really fast.

[spullara]

the additional requirement to set up the schema is kind of onerous.

[networked]

Shameless plug: Sqawk can do nearly the same without you defining a schema.

  $ ps aux | sqawk -output table \
                   'select user, round(sum("%mem"), 2) as memtotal
                    from a
                    group by user
                    order by memtotal desc' \
                   header=1
  ┌────────┬────┐
  │dbohdan │67.1│
  ├────────┼────┤
  │  root  │3.5 │
  ├────────┼────┤
  │ avahi  │0.0 │
  ├────────┼────┤
  │ daemon │0.0 │
  ├────────┼────┤
  │message+│0.0 │
  ├────────┼────┤
  │ nobody │0.0 │
  ├────────┼────┤
  │  ntp   │0.0 │
  ├────────┼────┤
  │ rtkit  │0.0 │
  ├────────┼────┤
  │ syslog │0.0 │
  ├────────┼────┤
  │ uuidd  │0.0 │
  ├────────┼────┤
  │whoopsie│0.0 │
  └────────┴────┘

Link: https://github.com/dbohdan/sqawk