first draft read replicas

content/200-concepts/100-components/02-prisma-client/065-read-replicas.mdx

@@ -0,0 +1,55 @@
+---
+title: 'Read replicas'
+metaTitle: 'Read replicas'
+metaDescription: 'This page explains how to set up and use read replicas with Prisma Client'
+---
+
+<TopBlock>
+
+You can add read replication in your application using the [`@prisma/extension-read-replicas`] Prisma Client extension.
+
+</TopBlock>
+
+Install the extension in your project:
+
+```terminal
+npm install @prisma/extension-read-replicas
+```
+
+```ts
+import { PrismaClient } from '@prisma/client'
+import { readReplicas } from '@prisma/extension-read-replicas'
+
+const prisma = new PrismaClient().$extends(
+  readReplicas({
+    url: process.env.DATABASE_URL_REPLICA,
+  })
+)
+```
+
+```ts
+const prisma = new PrismaClient().$extends(
+  readReplicas({
+    url: [
+      process.env.DATABASE_URL_REPLICA_1,
+      process.env.DATABASE_URL_REPLICA_2,
+    ],
+  })
+)
+```
+
+You can use the `$primary()` method to execute queries through against your primary database instance:
+
+```ts
+const posts = await prisma.$primary().post.findMany()
+```
+
+You can use the `$replica()` method to explicitly execute your query against a replica instead of your primary database:
+
+```ts
+const result = await prisma.$replica().$queryRaw`SELECT ...`
+```
+
+## Going further
+
+Try it out and share your feedback with us [here](https://github.com/prisma/extension-read-replicas/issues/new).