DYNDB127: GSI/LSI index name conflict

Field	Value
Code	DYNDB127
Severity	Error

Message

Index name '{0}' on entity '{1}' is used as both a GSI and an LSI. An index name must be exclusively GSI or LSI.

Description

A DynamoDB index name cannot be used as both a Global Secondary Index and a Local Secondary Index within the same entity. Use distinct index names for GSI and LSI. GSIs and LSIs have fundamentally different key schemas and projection behaviors.

Example

The following code triggers this diagnostic:

[DynamoDbTable("Orders")]
public partial class Order
{
    [PartitionKey]
    [DynamoDbAttribute("pk")]
    public string Pk { get; set; } = string.Empty;

    [SortKey]
    [DynamoDbAttribute("sk")]
    public string Sk { get; set; } = string.Empty;

    [GsiPartitionKey("date-index")]
    [DynamoDbAttribute("status")]
    public string Status { get; set; } = string.Empty;

    [LsiSortKey("date-index")]
    [DynamoDbAttribute("createdAt")]
    public DateTime CreatedAt { get; set; }
}

Fix

The corrected version:

[DynamoDbTable("Orders")]
public partial class Order
{
    [PartitionKey]
    [DynamoDbAttribute("pk")]
    public string Pk { get; set; } = string.Empty;

    [SortKey]
    [DynamoDbAttribute("sk")]
    public string Sk { get; set; } = string.Empty;

    [GsiPartitionKey("status-index")]
    [DynamoDbAttribute("status")]
    public string Status { get; set; } = string.Empty;

    [LsiSortKey("lsi-created")]
    [DynamoDbAttribute("createdAt")]
    public DateTime CreatedAt { get; set; }
}