# Description of Changes
#5300 changed the backing table schema of views. While this technically
isn't a breaking change because these tables are ephemeral, the schema
is not ephemeral, so it does require us to update the schema by dropping
and re-adding views once on initial startup.
# API and ABI breaking changes
None
# Expected complexity level and risk
1.5
# Testing
Auto-migration unit tests
# Description of Changes
Specifically:
- The number of objects read during replay
- The number of bytes read from disk during replay
- The time spent hashing objects during replay
# API and ABI breaking changes
Not considered breaking, but this patch does add a new label to a
pre-existing metric `spacetime_replay_snapshot_read_time_seconds`.
# Expected complexity level and risk
1.5
# Testing
Updates a pre-existing test
## Summary
Adding `#[unique]` or `#[primary_key]` to an existing column currently
triggers `AutoMigrateError::AddUniqueConstraint`, forcing a full
database clear to apply the schema change. This PR makes it a
non-breaking migration by validating existing data first:
- **If all values are unique**: constraint is added seamlessly
(non-breaking migration)
- **If duplicates exist**: migration fails with a detailed error listing
up to 10 duplicate groups
## Changes
- `auto_migrate.rs`: Replace hard `AddUniqueConstraint` error with
`CheckAddUniqueConstraintValid` precheck + `AddConstraint` migration
step
- `update.rs`: Implement precheck (full table scan, project constrained
columns, count duplicates) and `AddConstraint` step execution
- `relational_db.rs`: Expose `create_constraint()` (counterpart to
existing `drop_constraint()`)
- `traits.rs` / `datastore.rs`: Add `create_constraint_mut_tx` to
`MutTxDatastore` trait
- `mut_tx.rs`: Make `create_constraint` public
- `formatter.rs`: Format the new `AddConstraint` step
## Safety
- **Transaction safety**: Precheck and constraint creation run in the
same `MutTx` — no window for concurrent duplicate inserts
- **Index creation**: `auto_migrate_indexes()` already handles adding
the backing btree index (with `is_unique=true` from the new schema). The
constraint step only adds metadata.
- **Rollback**: If the precheck finds duplicates, the entire migration
aborts before any changes are applied
- **Error quality**: Duplicate error shows table name, column names, and
up to 10 example duplicate values with counts
## Example error output
```
Precheck failed: cannot add unique constraint 'Users_email_key' on table 'Users' column(s) [email]:
3 duplicate group(s) found.
- String("alice@example.com") appears 2 times
- String("bob@example.com") appears 3 times
- String("charlie@example.com") appears 2 times
```
## Test plan
- [x] All 12 `auto_migrate` tests pass
- [x] `cargo check` passes for `spacetimedb-schema` and
`spacetimedb-core`
- [x] Verified the previously-expected `AddUniqueConstraint` error test
is updated
- [x] Manual test: add `#[unique]` to existing column with clean data →
succeeds
- [x] Manual test: add `#[unique]` to existing column with duplicates →
fails with detailed error
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Co-authored-by: Mazdak Farrokhzad <twingoow@gmail.com>
Co-authored-by: Zeke Foppa <196249+bfops@users.noreply.github.com>
Co-authored-by: clockwork-labs-bot <clockwork-labs-bot@users.noreply.github.com>
# Description of Changes
In order to be able to suspend databases based on memory usage.
Reports memory usage for wasm linear memory as well as the v8 heap. Also
reports page-level memory for tables.
It does not report memory usage for indexes.
# API and ABI breaking changes
None
# Expected complexity level and risk
1.5
# Testing
Testing added in the private counterpart which handles enforcement of
memory limits.
# Description of Changes
Moves `RelationalDB` and related database code into a new
`spacetimedb-engine` crate.
The main motivation is to tighten dependency control around the engine
layer and isolate `RelationalDB`
behind a crate boundary.
- Majority of this PR is code-motion.
- Removes direct production dependence on `tokio` from
`spacetimedb-engine`.
- Keeps `tokio` only as a dev-dependency for test-only code in
`spacetimedb-engine`.
- This is intended to be a structural refactor only and should not
result in any functional change in
production.
- Adds a CI check to ensure `spacetimedb-engine` continues to compile in
simulation mode
# API and ABI breaking changes
NA
# Expected complexity level and risk
1.5.
# Testing
Existing tests should be enough.
---------
Co-authored-by: clockwork-labs-bot <clockwork-labs-bot@users.noreply.github.com>
joshua-spacetime