diff --git a/spec/focus/postgresql.nix b/spec/focus/postgresql.nix
new file mode 100644
index 00000000..22d99ced
--- /dev/null
+++ b/spec/focus/postgresql.nix
@@ -0,0 +1,12 @@
+{ pkgs
+, config
+, ...}: {
+  services.postgresql = {
+    enable = true;
+    dataDir = "/nix/persist/service/postgresql/${config.services.postgresql.package.psqlSchema}";
+
+    package = pkgs.postgresql_15;
+  };
+
+  global.fs.zfs.mountpoints."/nix/persist/service/postgresql" = "service/postgresql";
+}