This is a follow up question to [Is Postgres ideal for data which keeps increasing?](https://dba.stackexchange.com/questions/297662/is-postgres-ideal-for-datahierarchical-which-keeps-increasing)

To give an overview, Events and Participants are the main entities.
There are 1000 events and 10M participants for each event.

Query : In Event_Participant_Table, Get Participants who registered for an event

The table contains 1000 * 10M records.

Do we need to search all 1000 * 10M records and how efficiently can we partition this in PostgreSQL as previously the query is per defined eventId.

Postgres : 12+