CSharpDB v4.6.6

CSharpDB 4.6.6

CSharpDB 4.6.6 improves durable write throughput, prepared queries, and bounded
primary-key reads while strengthening reader snapshot, buffered-row, and concurrent
WAL-read correctness.
These notes cover changes since v4.6.5.

Query and write improvements

• Reuse prepared SELECT plans across parameter values and support bounded integer
  primary-key ranges through pooled readers and ordinary queries.
• Preserve reader catalog snapshots across commits and checkpoints, including
  schema metadata used by existing readers.
• Preserve committed row-count metadata during writes and restore it after
  publication, avoiding unnecessary full-table scans for reader COUNT(*) queries.
• Reduce table-scan, LIMIT, snapshot-pager, and leaf-prefetch allocations. Forward
  intact row batches while preserving ownership and mixed row/batch traversal.
• Streamline primary-key mutations and INSERT execution by reusing column ordinals,
  avoiding per-row observer allocations, and skipping redundant canonical value
  conversions.
• Reduce durable-write checkpoint stalls and improve WAL/checkpoint lifecycle
  handling and storage-page ownership.

Storage correctness

• Prevent checkpoint reset or retained-tail compaction from invalidating WAL
  offsets used during write-conflict resolution. This fixes a concurrency race
  that could cause short WAL reads or return incorrect page contents.
• Defer checkpoint finalization while durable commits still have unpublished WAL
  offsets, preserving correct reads after those commits complete.
• Add deterministic regression coverage for reset and compaction, including stale
  offsets that remain within file bounds, cancellation, lock release, and forward
  progress. The database and WAL formats are unchanged.

Dependencies and maintenance

• Update gRPC/Protobuf, SQL Server migration dependencies, WebView2, OpenTelemetry,
  Scalar, and test tooling.
• Retain Microsoft.OpenApi 2.12.0 for compatibility with
  Microsoft.AspNetCore.OpenApi 10.0.12 on .NET 10.

Performance guardrails

• Validate performance evidence integrity and reject incomplete or inconsistent
  comparison evidence.