Legacy Semantic Kernel Memory Stores

Tip

We recommend using the Vector Store abstractions instead of the legacy Memory Stores. For more information on how to use the Vector Store abstractions start here.

Semantic Kernel provides a set of Memory Store abstractions where the primary interface is Microsoft.SemanticKernel.Memory.IMemoryStore.

Memory Store vs Vector Store abstractions

As part of an effort to evolve and expand the vector storage and search capbilities of Semantic Kernel, we have released a new set of abstractions to replace the Memory Store abstractions. We are calling the replacement abstractions Vector Store abstractions. The purpose of both are similar, but their interfaces differ and the Vector Store abstractions provide expanded functionality.

Characteristic	Legacy Memory Stores	Vector Stores
Main Interface	IMemoryStore	IVectorStore
Abstractions nuget package	Microsoft.SemanticKernel.Abstractions	Microsoft.Extensions.VectorData.Abstractions
Naming Convention	{Provider}MemoryStore, e.g. RedisMemoryStore	{Provider}VectorStore, e.g. RedisVectorStore
Supports record upsert, get and delete	Yes	Yes
Supports collection create and delete	Yes	Yes
Supports vector search	Yes	Yes
Supports choosing your preferred vector search index and distance function	No	Yes
Supports multiple vectors per record	No	Yes
Supports custom schemas	No	Yes
Supports metadata pre-filtering for vector search	No	Yes
Supports vector search on non-vector databases by downloading the entire dataset onto the client and doing a local vector search	Yes	No

Available Memory Store connectors

Semantic Kernel offers several Memory Store connectors to vector databases that you can use to store and retrieve information. These include:

Service	C#	Python
Vector Database in Azure Cosmos DB for NoSQL	C#	Python
Vector Database in vCore-based Azure Cosmos DB for MongoDB	C#	Python
Azure AI Search	C#	Python
Azure PostgreSQL Server	C#
Azure SQL Database	C#
Chroma	C#	Python
DuckDB	C#
Milvus	C#	Python
MongoDB Atlas Vector Search	C#	Python
Pinecone	C#	Python
Postgres	C#	Python
Qdrant	C#
Redis	C#
Sqlite	C#
Weaviate	C#	Python