Env-var lookups via `GET
/api/v1/projects/:projectRef/envvars/:slug/:name` run a Prisma
`findMany` on `EnvironmentVariableValue` filtered by `environmentId` +
`isSecret`. The only existing indexes are the primary key and a unique
on `(variableId, environmentId)`, so `environmentId` is never the
leading column — the planner falls back to a Parallel Seq Scan over the
whole table to find what is, in practice, a handful of rows per
environment.
Two changes:
- Add a btree index on `EnvironmentVariableValue(environmentId)` so the
planner switches to an index scan. The composite `(variableId,
environmentId)` unique stays in place; the new index is purely additive.
- Route the `findMany` inside `getEnvironmentWithRedactedSecrets`
through the read replica via a new `replicaClient` constructor param on
the repository (defaulting to `$replica`, mirroring how `prismaClient`
defaults to `prisma`). Writes and read-after-write methods stay on the
primary.
## Test plan
- [ ] `pnpm run typecheck --filter webapp`
- [ ] Confirm `EXPLAIN` plan flips from Parallel Seq Scan to an index
scan
- [ ] Existing env-var route tests still pass
Eric Allam
aec7e0a93d