Postgres read slaves?

Is there a way to connect the orm to use a read slave for selects and master for writes?

11 Replies

There is no config option or something like that But you could have 2 different instances of Drizzle, each one fed with the same schema, but a different connection string I don't see any issues with running that set up You would use one instance or the other depending on what you're doing

pandareaper•16mo ago

It would be good to see Drizzle support this more natively like many other ORMs do. As an ORM it is well positioned to know read vs write queries and automatically route queries to the correct connection/pool

Angelelz•16mo ago

Would you like to submit a feature request? You could also create a wrapper object that would handle it for you.

import dbRead from "...";
import dbWrite from "...";

export const db = {
  select: dbRead.select,
  update: dbWrite.select,
  insert: dbWrite.insert,
  delete: dbWrite.delete,
  query: dbRead.query,
}

import dbRead from "...";
import dbWrite from "...";

export const db = {
  select: dbRead.select,
  update: dbWrite.select,
  insert: dbWrite.insert,
  delete: dbWrite.delete,
  query: dbRead.query,
}

pandareaper•16mo ago

True, I might consider something like that as well. I do have some more advanced read replica query patterns where I would route based on async context / environment configuration where this might be useful

Angelelz•16mo ago

Are there ORMs that handle that for you?

pandareaper•16mo ago

Not that specifically, it would be quite a niche pattern so I wouldn’t expect any to support it either