Impacted versions: V15 with Enterprise

Steps to reproduce: Create as much records like 40k or 50k in calender.event with online appointments (Past / Future / Present date records).

Current behavior : without customisation, any user go to Appointment menu in website and user try to select any appointment it will take more than 1 minute to load.

Below is the appointment type configuration and we have total 10 appointments.

Appointment Duration | 01:30 hours
Schedule Appointment | at least 01:00 hours before and not after 150 days
Allow Cancelling | until 01:00 hours before
Timezone | Europe/Brussels
Location | Café Costume Antwerp
Assignment Method | Random
**Available employee** :- 2 to 7 employee max
**Availability** : Monday to Saturday 10 AM to 19 PM



Expected behavior: When user click to appointment from website, it will work smooth without taking 30 seconds and here it will take more than 1 minutes.

Is any one resolved such loading issue?

Below modules we are using without single customisation. 

appointments, website, website_appointment

Thanks in advance

Harsh Dhaduk