EfficientDynamoDb is a high-performance C# library for DynamoDb with a huge focus on efficient resources utilization. Due to DynamoDb extreme scaling capabilities it is very important for backend services to not waste valuable CPU time on unmarshalling responses. EfficientDynamoDb is capable of zero allocation deserialization. In general it allocates up to 26X less memory and is up to 21X faster than official .NET AWS SDK.

Benchmarks

Comparison with official DynamoDb SDK for .NET

|          Method | Items |         Mean |      Error |     StdDev |  Gen 0 |  Gen 1 | Gen 2 |  Allocated |
|---------------- |------ |-------------:|-----------:|-----------:|-------:|-------:|------:|-----------:|
|    EfficientDdb |    10 |      79.1 us |     0.8 us |     0.7 us |    4.3 |      - |     - |    18.2 KB |
|     aws-sdk-net |    10 |     620.8 us |     7.2 us |     6.0 us |   85.9 |   18.5 |     - |   352.3 KB |
|                 |       |              |            |            |        |        |       |            |
|    EfficientDdb |   100 |     484.1 us |     1.7 us |     1.6 us |   29.2 |    5.8 |     - |   120.8 KB |
|     aws-sdk-net |   100 |   6,127.1 us |   120.6 us |   148.1 us |  500.0 |  250.0 |     - |  3066.6 KB |
|                 |       |              |            |            |        |        |       |            |
|    EfficientDdb |  1000 |   4,733.0 us |    24.2 us |    22.7 us |  195.3 |   93.7 |     - |  1147.5 KB |
|     aws-sdk-net |  1000 |  99,438.8 us | 1,951.4 us | 3,518.9 us | 5200.0 | 1600.0 | 600.0 | 30177.0 KB |

Every benchmark simulates QUERY request to DynamoDb that return responses with number of items specified in Items column. All network calls are excluded and data is served from memory to eliminate network inconsistency in benchmarks. Entity contains various data types including lists, hashsets, strings, etc.

Configuration

BenchmarkDotNet=v0.12.1, OS=Windows 10.0.19041.685 (2004/?/20H1)
Intel Core i7-8550U CPU 1.80GHz (Kaby Lake R), 1 CPU, 8 logical and 4 physical cores
.NET Core SDK=3.1.110
  [Host]     : .NET Core 3.1.10 (CoreCLR 4.700.20.51601, CoreFX 4.700.20.51901), X64 RyuJIT
  DefaultJob : .NET Core 3.1.10 (CoreCLR 4.700.20.51601, CoreFX 4.700.20.51901), X64 RyuJIT

Introduction

EfficientDynamoDb has two types of API: high-level and low-level. High-level API, in most cases, is on-par with low-level in terms of raw processing speed and requires fewer memory allocations. It is recommended to use the high-level API in most cases unless you're sure about what you do.

GetItem

Retrieves a single item.

var user = await _context.GetItemAsync<UserEntity>("qwerty", "1234");

Query

Retrieves a list of items that match key and filter conditions.

var items = await _context.Query<UserEntity>()
    .WithKeyExpression(Condition<UserEntity>.On(x => x.Username).EqualsTo("qwerty"))
    .WithFilterExpression(Condition<UserEntity>.On(x => x.Age).GreaterThanOrEqualsTo(18))
    .ToListAsync();

UpdateItem

Edits an existing item's attributes or adds a new item to the table if it does not already exist.

await ddbContext.UpdateItem<UserEntity>()
    .WithPrimaryKey("partitionKey", "sortKey")
    .On(x => x.FirstName).Assign("John")
    .On(x => x.LastName).Assign("Doe")
    .ExecuteAsync();

TransactWriteItems

Atomically applies one of four operations per item within the same AWS account and Region.

await context.TransactWrite()
    .WithItems(
        Transact.PutItem(new UserEmailEntity("[email protected]")),
        Transact.ConditionCheck<UserEntity>()
            .WithPrimaryKey("partitionKey", "sortKey")
            .WithCondition(Condition<UserEntity>.On(x => x.Verified).EqualsTo(false))
    )
    .ExecuteAsync();

Visit our website for a complete operations list.

Compatibility with official AWS SDK for .NET

EfficientDynamoDb API is quite similar to the official DynamoDB SDK for .NET, so migration should be relatively easy. The most significant differences are described in the compatibility guide.

Documentation