We're planning to implement authzed/spicedb first time in our product but not sure which storage system to go for.. They provide in memory, Postgres, Cockroach, Spanner and MySQL.
We don't want to use in memory storage but we're confused between other three options.
As of now tried nothing as this is new for me.
The storage systems available for SpiceDB each have trade-offs, but can usually be recommended with this general rule of thumb:
If your goal is to run SpiceDB clusters around the world and have them all share the same data -- use CockroachDB or Spanner. Spanner is best if all of your infrastructure runs exclusively on Google Cloud.
If your goal is to run SpiceDB in a single region/datacenter, then use PostgreSQL. At the time of this post, MySQL isn't as performant and I cannot recommended it for production usage unless your organization has a hard requirement and is willing to contribute to the open source project.
If you haven't already, check out the official doc on Selecting a Datastore.