Vector Store changes - May 2025

Nuget Package Renames

The following nuget packages have been renamed for clarity and length.

Old Package Name	new Package Name
Microsoft.SemanticKernel.Connectors.AzureCosmosDBMongoDB	Microsoft.SemanticKernel.Connectors.CosmosMongoDB
Microsoft.SemanticKernel.Connectors.AzureCosmosDBNoSQL	Microsoft.SemanticKernel.Connectors.CosmosNoSql
Microsoft.SemanticKernel.Connectors.Postgres	Microsoft.SemanticKernel.Connectors.PgVector
Microsoft.SemanticKernel.Connectors.Sqlite	Microsoft.SemanticKernel.Connectors.SqliteVec

Type Renames

As part of our formal API review before GA various naming changes were proposed and adopted, resulting in the following name changes. These should help improve clarity, consistency and reduce type name length.

All names of the various Semantic Kernel supported implementations of VectorStoreCollection have been renamed to shorter names using a consistent pattern.

*VectorStoreRecordCollection is now *Collection. E.g. PostgresVectorStoreRecordCollection -> PostgresCollection.

Similary all related options classes have also changd.

*VectorStoreRecordCollectionOptions is now *CollectionOptions. E.g. PostgresVectorStoreRecordCollectionOptions -> PostgresCollectionOptions.

Property Renames

Namespace	Class	Old Property Name	New Property Name
Microsoft.Extensions.VectorData	VectorStoreKeyAttribute	StoragePropertyName	StorageName
Microsoft.Extensions.VectorData	VectorStoreDataAttribute	StoragePropertyName	StorageName
Microsoft.Extensions.VectorData	VectorStoreVectorAttribute	StoragePropertyName	StorageName
Microsoft.Extensions.VectorData	VectorStoreKeyProperty	DataModelPropertyName	Name
Microsoft.Extensions.VectorData	VectorStoreKeyProperty	StoragePropertyName	StorageName
Microsoft.Extensions.VectorData	VectorStoreKeyProperty	PropertyType	Type
Microsoft.Extensions.VectorData	VectorStoreDataProperty	DataModelPropertyName	Name
Microsoft.Extensions.VectorData	VectorStoreDataProperty	StoragePropertyName	StorageName
Microsoft.Extensions.VectorData	VectorStoreDataProperty	PropertyType	Type
Microsoft.Extensions.VectorData	VectorStoreVectorProperty	DataModelPropertyName	Name
Microsoft.Extensions.VectorData	VectorStoreVectorProperty	StoragePropertyName	StorageName
Microsoft.Extensions.VectorData	VectorStoreVectorProperty	PropertyType	Type
Microsoft.Extensions.VectorData	DistanceFunction	Hamming	HammingDistance

The VectorStoreRecordDefinition property on collection options classes have been renamed to just Definition.

Method Renames

The CreateCollectionIfNotExistsAsync method on the Collection has been renamed to EnsureCollectionExistsAsync.

The DeleteAsync method on the *Collection and VectorStore has been renamed to EnsureCollectionDeletedAsync. This more closely aligns with the behavior of the method, which will delete a collection if it exists. If the collection does not exist it will do nothing and succeed.

Interface to base abstract class

The following interfaces have been changed to base abstract classes.

Namespace	Old Interface Name	New Type Name
Microsoft.Extensions.VectorData	IVectorStore	VectorStore
Microsoft.Extensions.VectorData	IVectorStoreRecordCollection	VectorStoreCollection

Whereever you were using IVectorStore or IVectorStoreRecordCollection before, you can now use VectorStore and VectorStoreCollection instead.

Merge of `SearchAsync` and `SearchEmbeddingAsync`

The SearchAsync and SearchEmbeddingAsync methods on the Collection have been merged into a single method: SearchAsync.

Previously SearchAsync allowed doing vector searches using source data that would be vectorized inside the collection or in the service while SearchEmbeddingAsync allowed doing vector searches by providing a vector.

Now, both scenarios are supported using the single SearchAsync method, which can take as input both source data and vectors.

The mechanism for determining what to do is as follows:

If the provided value is one of the supported vector types for the connector, search uses that.
If the provided value is not one of supported vector types, the connector checks if an IEmbeddingGenerator is registered, with the vector store, that supports converting from the provided value to the vector type supported by the database.
Finally, if no compatible IEmbeddingGenerator is available, the method will throw an InvalidOperationException.

Support for Dictionary<string, object?> models using `*DynamicCollection` and `VectorStore.GetDynamicCollection`

To allow support for NativeOAT and Trimming, where possible and when using the dynamic data model, the way in which dynamic data models are supported has changed. Specifically, how you request or construct the collection has changed.

Previously when using Dictionary<string, object?> as your data model, you could request this using VectorStore.GetCollection, but now you will need to use VectorStore.GetDynamicCollection

// Before
PostgresVectorStore vectorStore = new PostgresVectorStore(myNpgsqlDataSource)
vectorStore.GetCollection<string, Dictionary<string, object?>>("collectionName", definition);

// After
PostgresVectorStore vectorStore = new PostgresVectorStore(myNpgsqlDataSource, ownsDataSource: true)
vectorStore.GetDynamicCollection<string, Dictionary<string, object?>>("collectionName", definition);

VectorStore and VectorStoreRecordCollection is now Disposable

Both VectorStore and VectorStoreRecordCollection is now disposable to ensure that database clients owned by these are disposed properly.

When passing a database client to your vector store or collection, you have the option to specify whether the vector store or collection should own the client and therefore also dispose it when the vector store or collection is disposed.

For example, when passing a datasource to the PostgresVectorStore passing true for ownsDataSource will cause the PostgresVectorStore to dispose the datasource when it is disposed.

new PostgresVectorStore(dataSource, ownsDataSource: true, options);

`CreateCollection` is not supported anymore, use `EnsureCollectionExistsAsync`

The CreateCollection method on the Collection has been removed, and only EnsureCollectionExistsAsync is now supported. EnsureCollectionExistsAsync is idempotent and will create a collection if it does not exist, and do nothing if it already exists.

`VectorStoreOperationException` and `VectorStoreRecordMappingException` is not supported anymore, use `VectorStoreException`

VectorStoreOperationException and VectorStoreRecordMappingException has been removed, and only VectorStoreException is now supported. All database request failures resulting in a database specific exception are wrapped and thrown as a VectorStoreException, allowing consuming code to catch a single exception type instead of a different one for each implementation.

Not Applicable

These changes are currently only applicable in C#

Coming soon