Once you’ve added items to an encrypted index, you can query the index to retrieve the items that match a given query. This is done via query(): 
# Example query
query_vector = [0.5, 0.9, 0.2, 0.7]
top_k = 10

# Perform query
results = index.query(query_vectors=query_vector, top_k=top_k)

print(results)
# Example results (nested list format)
# [[{"id": "item_12", "distance": 0.01}, {"id": "item_7", "distance": 0.04}, ...]]

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Query Parameters

You can specify additional parameters for the query, such as:
  • top_k: the number of results to return.
  • n_probes: the number of clusters to search for each query vector.
  • filters: metadata filters to apply to the query (dictionary format).
  • include: item fields to return (e.g., ["distance", "metadata"]).
  • greedy: whether to perform a greedy search (higher recall but slower).
# Example query with parameters
query_vector = [0.5, 0.9, 0.2, 0.7]
top_k = 10
n_probes = 5
filters = {"age": {"$gt": 18}}
include = ["distance", "metadata"]

# Perform query
results = index.query(
    query_vectors=query_vector, 
    top_k=top_k, 
    n_probes=n_probes, 
    filters=filters, 
    include=include
)

print(results)
# Example results
# [[{"id": "item_12", "distance": 0.01, "metadata": {"age": 25}}, ...]]

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Batched Queries

It’s also possible to perform batch queries by passing multiple query vectors to query(): 
# Example batch query
query_vectors = [[0.5, 0.9, 0.2, 0.7], [0.1, 0.3, 0.8, 0.6]]
top_k = 10

# Perform batch query
results = index.query(
  query_vectors=query_vectors, 
  top_k=top_k
)

print(results)
# Returns nested results: one list per query vector
# [[results_for_query_1], [results_for_query_2]]

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Querying with Metadata Filters

You can filter query results based on metadata fields. For example, to filter items where the age field is greater than 18, you can use the following filter: 
{"age": {"$gt": 18}}
This filter will return items where the age field is greater than 18. You can also use other comparison operators such as $lt, $gte, $lte, $eq, and $ne. For more details on metadata filters, see the Metadata Filtering guide.

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Automatic Embedding Generation

To use automatic embedding generation, use the Docker Service or install with pip install cyborgdb-service[embeddings]
If you provided an embedding_model during index creation, you can automatically generate embeddings for queries by providing query_contents to the query() call: 
# ... index creation and embedding model setup
embedding_model = "sentence-transformers/all-MiniLM-L6-v2"
index = client.create_index("my_index", index_key, index_config, embedding_model)

# ... Add items to the encrypted index ...

# Example semantic query
query_contents = "What is the capital of France?"
top_k = 10

# Perform query
results = index.query(query_contents=query_contents, top_k=top_k)
This feature allows you to perform semantic search using natural language queries. The service will automatically generate embeddings for your query text using the specified embedding model.

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Retrieving Items Post-Query

In certain applications, such as RAG, it may be desirable to retrieve matching items after a query. This is possible via get(), which retrieves and decrypts item added via upsert(). For more details, see the Get Items guide.

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Index Training for Optimal Performance

For optimal query performance, you should train your index after adding a significant amount of data (typically more than 50,000 vectors). The CyborgDB service supports index training to improve query speed and accuracy. Queries will initially use exhaustive search, which is fine for small datasets. Once you have a substantial amount of data, train the index for better performance. For more details, see Training an Encrypted Index.

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API Reference

For more information on querying encrypted indexes, refer to the API reference:

REST API Reference

REST API reference for /v1/vectors/query

Python SDK Reference

API reference for query() in Python

JS/TS SDK Reference

API reference for query() in JavaScript/TypeScript

Go SDK Reference

API reference for Query() in Go