# v0.30.0 — Pre-GA Correctness & Stability Sprint

**Status: ✅ Released** | **Scope: Medium** (~7 weeks)

> v0.30.0 delivered correctness and durability fixes, stronger test coverage,
> and documentation backfill before the 1.0 release.

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## What shipped

v0.30.0 completed a planned quality milestone before v1.0.0. The release
focused on correctness, durability, test coverage, and documentation.

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## Correctness fixes

**Multi-table JOIN phantom rows (EC-01)**

A subtle edge case in multi-table JOIN differential updates could cause
phantom rows in multi-cycle mutation sequences. The release fixed the issue and
added a deterministic regression test.

**Atomic snapshot and restore**

Snapshot and restore operations use a database sub-transaction to prevent an
orphan table or truncated storage table after a failed operation.

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## Stability and safety

**Bounded caches**

The release bounded the internal caches that hold compiled query templates.

**Internationalisation-safe error classification**

Error classification now uses SQLSTATE codes rather than English message
fragments, so it works when PostgreSQL uses a different message locale.

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## Documentation backfill

- The upgrade guide (`UPGRADING.md`) is extended to cover every version
  from v0.15.0 through v0.27.0.
- All configuration settings introduced since v0.23.0 are documented in
  `CONFIGURATION.md`.
- New error codes have clear explanations, hints, and remediation steps in
  `ERRORS.md`.
- A first-party Grafana dashboard JSON file ships in the repository.
- The SQL reference is completed for all snapshot, schedule-planner,
  cluster-observability, and metrics functions.

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## Test coverage

- Fuzz targets cover the WAL decoder, MERGE template generator, and snapshot
  SQL builder. CI replays their stored corpora.
- Multi-database soak tests remain in the separate stability workflow.
- The deterministic EC-01 reproducer replaces the previously flaky TPC-H
  Q07 test.
- The detailed plan deferred benchmarks for snapshots, scheduling, cluster
  metrics, template-cache paths, IVM apply, WAL polling, and multi-database
  fairness. The current measured-work scope is in [v0.108.0](v0.108.0.md).

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## Scope

The release was weighted towards test coverage and documentation, with no new
user-facing SQL features. Later follow-up work remained in the release plans
that followed v0.30.0.

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