I would expect this to be a single query, e.g. a FETCH JOIN in other ORM tools. But to my surprise it did this:

prisma:query SELECT `dev`.`Post`.`id`, `dev`.`Post`.`title`, `dev`.`Post`.`content`, `dev`.`Post`.`published`, `dev`.`Post`.`authorId` FROM `dev`.`Post` WHERE 1=1 LIMIT ? OFFSET ?

prisma:query SELECT `dev`.`User`.`id`, `dev`.`User`.`email`, `dev`.`User`.`name` FROM `dev`.`User` WHERE `dev`.`User`.`id` IN (?) LIMIT ? OFFSET ?

[
  {
    id: 1,
    title: 'Hello World',
    content: null,
    published: false,
    authorId: 2,
    author: { id: 2, email: <mailto:'maria@prisma.io|'maria@prisma.io>', name: 'Maria' }
  }
]

Hey @Marcel Overdijk 👋 thanks a lot for digging into this! We have a number of performance improvements planned for Prisma Client (for the Beta we focused on stability instead of performance 🙂 ). Can you please create a GitHub issue with these findings 🙂 https://github.com/prisma/prisma/issues/new

Yes I will do that, thx for following up