Postgres database size monitoring

[Sathish Reddy <sathishreddy.postgresql@xxxxxxxxx>]

Hi 

  We are planning to genarate weekly report for database size growth as like in month 4 weeks on 1st week second week 3rd week 4th week .. genarate report to compare size all databases..

   Any one have idea on these help us ..we are using RDS  postgres.

Thanks 

Sathishreddy