Shardis.Query.EntityFrameworkCore 0.1.0-prerelease0086

Shardis.Query.EntityFrameworkCore

Entity Framework Core query executor for Shardis (Where/Select pushdown, unordered streaming).

Install

dotnet add package Shardis.Query.EntityFrameworkCore --version 0.1.*

When to use

• Your shard-local persistence is EF Core and you want query pushdown and streaming.
• You need a tested executor that integrates with DbContext per shard.

What’s included

• EntityFrameworkCoreShardQueryExecutor — concrete executor that translates queries into EF Core operations.
• EntityFrameworkCoreShardFactory<TContext> / PooledEntityFrameworkCoreShardFactory<TContext> for per-shard context creation.
• Wiring examples for registering DbContext instances per shard.

Quick start

// Build a shard factory (pure creation only)
var dbFactory = new EntityFrameworkCoreShardFactory<MyDbContext>(sid =>
    new DbContextOptionsBuilder<MyDbContext>()
        .UseSqlite($"Data Source=shard-{sid.Value}.db")
        .Options);

// (Optional) seed outside the factory
foreach (var sid in new[]{ new ShardId("0"), new ShardId("1") })
{
    await using var ctx = await dbFactory.CreateAsync(sid);
    // seed if empty
}

// Adapter to non-generic DbContext for executor
IShardFactory<DbContext> adapter = new DelegatingShardFactory<DbContext>((sid, ct) => new ValueTask<DbContext>(dbFactory.Create(sid)));

var exec = new EntityFrameworkCoreShardQueryExecutor(
    shardCount: 2,
    contextFactory: adapter,
    merge: (streams, ct) => UnorderedMerge.Merge(streams, ct));

var query = ShardQuery.For<Person>(exec)
    .Where(p => p.Age >= 30)
    .Select(p => p.Name);

var names = await query.ToListAsync();

Integration notes

• Works with Shardis.Query core abstractions; register per-shard DbContext factories in DI.
• Recommended DI approach using Shardis.DependencyInjection:

var services = new ServiceCollection()
    .AddShards<MyDbContext>(2, shard => new MyDbContext(BuildOptionsFor(shard)));

await using var provider = services.BuildServiceProvider();
var perShardFactory = provider.GetRequiredService<IShardFactory<MyDbContext>>();
IShardFactory<DbContext> adapter = new DelegatingShardFactory<DbContext>((sid, ct) => perShardFactory.CreateAsync(sid, ct));
var exec = new EntityFrameworkCoreShardQueryExecutor(2, adapter, (s, ct) => UnorderedMerge.Merge(s, ct));

Samples & tests

• Samples: samples

Configuration / Options

• PageSize: control the EF Core query page size for paged streaming (provider-specific).
• Shard factory: supply an IShardFactory<DbContext> (e.g. EntityFrameworkCoreShardFactory<TContext> + adapter) for pure creation; seed separately.

Capabilities & limits

• ✅ Pushes where/select operations to EF Core where supported.
• ⚠️ Ordered streaming can add latency and requires a stable key selector across shards.
• 🧩 Requires EF Core provider matching your database version.

Versioning & compatibility

• SemVer; see CHANGELOG: CHANGELOG

Contributing

• PRs welcome. See CONTRIBUTING

License

• MIT — see LICENSE

Links

• NuGet: Shardis.Query.EntityFrameworkCore on NuGet