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Milvus Limits

Milvus is committed to providing the best vector databases to power AI applications and vector similarity search. However, the team is continuously working to bring in more features and the best utilities to enhance user experience. This page lists out some known limitations that the users may encounter when using Milvus.

Length of a resource name

Resource Limit
Collection 255 characters
Field 255 characters
Index 255 characters
Partition 255 characters

Naming rules

The name of a resource can contain numbers, letters, and underscores (_). A resource name must start with a letter or an underscore (_).

Number of resources

Resource Limit
Collection 65,536
Connection / proxy 65,536

Number of resources in a collection

Resource Limit
Partition 4,096
Shard 16
Field 64
Index 1
Entity unlimited

Length of a string

Data type Limit
VARCHAR 65,535

Dimensions of a vector

Property Limit
Dimension 32,768

Input and Output per RPC

Operation Limit
Insert 64 MB
Search 64 MB
Query 64 MB

Load limits

In current release, data to be load must be under 90% of the total memory resources of all query nodes to reserve memory resources for execution engine.

Search limits

Vectors Limit
topk (number of the most similar result to return) 16,384
nq (number of the search requests) 16,384

Index limits on different search types

The following table provides an overview of the support for various search behaviors across different index types.

HNSW DISKANN FLAT IVF_FLAT IVF_SQ8 IVF_PQ SCANN GPU_IFV_FLAT GPU_IVF_PQ GPU_CAGRA GPU_BRUTE_FORCE SPARSE_INVERTED_INDEX SPARSE_WAND BIN_FLAT BIN_IVF_FLAT
Basic search Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
Partition search Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
Basic search with raw data retrieved Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
Basic search with pagination Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
Filtered search Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
Range search Yes Yes Yes Yes Yes Yes Yes No No No No No No Yes Yes
Grouping search Yes No Yes Yes No No No No No No No No No No No
Search with iterator Yes Yes Yes Yes Yes Yes Yes No No No No No No No No
Hybrid search Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes(Only RRFRanker) Yes(Only RRFRanker) Yes Yes
Query/Get Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
Query with iterator Yes Yes Yes Yes Yes Yes Yes No No No No Yes Yes Yes Yes
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