Roadmap

No-reflection, trim-safe typed collection API via CSharpDB.Generators with GetGeneratedCollectionAsync<T>(), GeneratedCollection<T>, generated field metadata, binary direct payloads for supported shapes, and NativeAOT-friendly model registration.

Separated collection write probes from the read-side B-tree routing-cache, reused traversal scratch during insert/replace, and buffered catalog mutation bookkeeping inside explicit transactions.

Recovered covered composite-index lookup optimization for queries that can be answered entirely from the index without touching the base table.

Configurable durable commit batch window to coalesce WAL fsync calls across concurrent transactions for higher write throughput.

Deduplicate SELECT output with DISTINCT. Multi-column indexes for broader query coverage.

Use indexes for <, >, <=, >=, BETWEEN — not just equality lookups.

Cache parsed ASTs and query plans to avoid re-parsing identical SQL statements.

Open a database fully in memory, load from disk, and save committed snapshots back to disk.

Nested scalar, array-element, nested array-object, Guid, temporal, and ordered text path indexes.

Merge underflowed pages on delete to reclaim space via borrow/merge with interior collapse.

Maintenance report, REINDEX, VACUUM/compact, fragmentation analysis, and database size report.

CSharpDB.Daemon host with full gRPC coverage for SQL, schema, procedures, collections, and maintenance.

Incremental/sliced auto-checkpointing to move work off the triggering commit path.

Lazy-resident durable storage with on-demand page loading and gRPC tunable file-cache.

ANALYZE command with persisted row counts, column NDV/min/max, and initial stats-guided index selection.

BackupAsync / RestoreAsync as first-class operations across direct, HTTP, gRPC, CLI, and Admin.

Native .csdbtable snapshots with fast Admin Import / Export, download or server-path destinations, CREATE EXTERNAL TABLE, sys.external_tables, read-only scans/joins, and embedded primary-key lookup indexes.

Validate/apply maintenance workflow that rewrites existing child tables with persisted FK metadata across direct, HTTP, gRPC, CLI, and Admin.

Visual banded-report designer with grouping, sorting, expressions, aggregate functions, page settings, and printable preview.

Done for the trusted in-process model: host-registered C# scalar functions, common SQL/Admin built-ins, trusted commands, Admin Forms/Reports/pipeline hooks, declarative form action sequences, and local Admin Forms C# code modules. Untrusted sandboxed UDF execution is intentionally out of scope.

Opt-in writable external table registrations over mutable .csdbx files, backed by CSharpDB B+tree storage and limited to INSERT, UPDATE, and DELETE in v1 while .csdbtable archives remain read-only.

ROW_NUMBER(), RANK(), DENSE_RANK(), LEAD(), LAG() for analytical queries.

Default expressions in column definitions and arbitrary expression-based constraints per column or table.

v1 support for single-column, column-level REFERENCES with optional ON DELETE CASCADE, plus metadata/tooling surfaces.

CSharpDB.Daemon now hosts the existing REST/HTTP /api surface and gRPC from one long-running process backed by the same warm daemon-hosted client. Standalone CSharpDB.Api remains supported for REST-only hosting.

Opt-in API-key mode protects REST /api/* and daemon gRPC calls with constant-time key comparison while keeping default no-auth behavior for compatibility.

Authorization, protected admin endpoint scopes, JWT/RBAC options, and TLS/mTLS deployment helpers for remote HTTP and gRPC access.

CSharpDB.Daemon can be packaged as a persistent background service across systemd, Windows Service, and launchd.

Self-contained daemon archives and install scripts ship for Windows, Linux, and macOS; dotnet tool, Docker, Homebrew, and winget distribution remain future work.

DbConnection.GetSchema() now exposes standard metadata collections for tooling and ORM schema discovery.

BINARY, NOCASE, NOCASE_AI, and ICU:<locale> collation now work across SQL and collection indexes; dedicated ordered SQL text index optimization remains future work.

Scalar subqueries, IN/EXISTS (including correlated), UNION, INTERSECT, EXCEPT across SELECT results.

Admin query builder with source canvas, join editing, design grid, SQL preview, and saved layouts.

Inverted index support with tokenization, stemming, and relevance ranking.

Current phase is complete: opt-in generated models provide GetGeneratedCollectionAsync<T>, generated descriptors/index bindings, binary direct payloads for supported shapes, JSON fallback for unsupported shapes, and trim/NativeAOT smoke coverage.

Streamline NuGet/analyzer packaging, templates, onboarding docs, and project setup for the opt-in generated collection path.

Expand generator support beyond the current scalar, scalar collection, nested scalar, and nested collection-scalar shapes.

Internal row-batch transport serves as the batch-first SQL execution foundation across batch-capable result boundaries, scans, joins, and generic aggregates.

Follow writable .csdbx storage with broader external-table indexes, planner costing, and multi-column lookup/range support beyond the current archive primary-key point-lookup path.

Deep engine/page compression remains planned; application-level payload compression is available as a sample/SDK pattern without changing the storage format.

Encrypt database and WAL files with passphrase-based key management and explicit plaintext/encrypted migration/export paths; implementation must meet the database-encryption plan entry criteria before shipping.

Current phase is complete: ANALYZE-driven stats-guided costing uses internal histograms, heavy hitters, composite-prefix summaries, skew-aware estimates, correlation-aware filters/joins, non-unique lookup costing, hash build-side choice, and bounded DP join reordering.

Current phase is complete: opt-in adaptive join execution can switch eligible index nested-loop joins to hash joins and flip inner hash build sides at safe pre-emission boundaries.

Stable SQL-first diagnostics expose sys.planner_histograms, sys.planner_heavy_hitters, sys.planner_index_prefix_stats, and EXPLAIN ESTIMATE FOR <query>.

Current phase is complete: WAL frame-chunk writes, chunked checkpoint page copies, shared snapshot/export batching, reusable B-tree copy utilities, and the close-out audit cover the main storage and maintenance write paths.

Advisory planner-stat persistence can stay deferred without weakening committed-row durability, and sys.table_stats.row_count_is_exact makes exact versus estimated row-count semantics explicit.

Opt-in UseDurableCommitBatchWindow(...) batches durable WAL flushes across contending in-process transactions — an expert measure-first knob rather than default behavior.

Explicit WriteTransaction conflict-detected retry flow, shared auto-commit non-insert isolation, and opt-in ConcurrentWriteTransactions for shared implicit inserts.

Opt-in concurrent write transactions now reserve shared row-id ranges and rebase hot right-edge insert pages against pending WAL images for improved insert fan-in.

Route API/daemon requests across multiple warm CSharpDB database files so independent tenants or shard keys can use separate WAL and commit paths, with v1 focused on single-shard writes and point reads.

Retained commit-log change feeds and reactive query subscriptions for read replicas, live Admin views, and event-driven applications.