why postgres process takes so much memory during day time

[Marcin Giedz <marcin.giedz@xxxxxxxx>]

Hi all, is there any way to figure out why particular postgres process takes more and more memory during the day? This process performes order data queries coming from order management system - exchange system. Normally it's about 0,5mln messages per day but after aprox 4h postgres process occupies :

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND                                                                                                                                                    
11920 pgsql     20   0   17,6g   9,7g 566572 S   2,6 10,4   2:40.47 postgres

Perhaps dev guys (our team) should change something inside our system or it's postgresql conf matter? Postgres engine is 9.6.7. Any hint on this please?

Thx

Marcin