Postgres queries are streaming. Ie. If the query result has 1 billion rows, but the client only has enough ram for 1 million rows, then the query will be slowe

Postgres queries are streaming. Ie. If the query result has 1 billion rows, but the client only has enough ram for 1 million rows, then the query will be slowed down until the client is ready to accept more rows. If the client is slowly processing through the result set, then the query can take many minutes/hours.