Optimizing search with multiple linked rows

Anvil Q&A
8

I seem to have been ably to shave of about ~1 second from all queries, by only fetching the data I actually need with fetch_only():

@anvil.server.callable('filter_by_country_or_status', require_user=True)
def filter_by_country_or_status(filter_tuple: tuple=None):
  result = None
  tl = TimerLogger('Server timer')
  tl.start('Server start')
  if not any(filter_tuple):
    try:
      filter_tuple = load_filters()
    except:
      return result
  else:
    store_filters(filter_tuple)
  tl.check('Server cookie check done')
    
  if filter_tuple[0] and filter_tuple[1]:
    customers = app_tables.customer.search(
      q.fetch_only('name', 'status'),
      status=filter_tuple[1]
    )
    tl.check('Server: Customers fetched.')
    
    result = app_tables.location.search(
      q.fetch_only('customer', 'address', 'country'),
      country=filter_tuple[0], 
      customer=q.any_of(*customers)
    )
    tl.check('Server: Locations fetched.')
    
  elif not filter_tuple[0] and filter_tuple[1]:
    # Status chosen
    customers = app_tables.customer.search(
      q.fetch_only('name', 'status'),
      status=filter_tuple[1]
    )
    
    result = app_tables.location.search(customer=q.any_of(*customers))
  elif filter_tuple[0] and not filter_tuple[1]:
    # Country chosen
    result = app_tables.location.search(
      q.fetch_only('customer', 'address', 'country'),
      country=filter_tuple[0]
    )
  else:
    result = app_tables.location.search()
  tl.end('Server end')
  return result