> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cyborg.co/llms.txt
> Use this file to discover all available pages before exploring further.

# Query

Retrieves the nearest neighbors for given query vectors.

```cpp theme={null}
QueryResults Query(Array2D<float>& query_vectors,
                   const QueryParams& query_params = QueryParams());
```

### Parameters

| Parameter       | Type                                  | Description                                                           |
| --------------- | ------------------------------------- | --------------------------------------------------------------------- |
| `query_vectors` | [`Array2D<float>`](../types#array2d)  | Query vectors to search.                                              |
| `query_params`  | [`QueryParams`](../types#queryparams) | *(Optional)* Parameters for querying, such as `top_k` and `n_probes`. |

<Tip> If this function is called on an index where `TrainIndex()` has not been executed, the query will use encrypted exhaustive search.
This may cause queries to be slower, especially when there are many vector embeddings in the index.</Tip>

### Returns

[`QueryResults`](#queryresults): Results `top_k` containing decrypted nearest neighbors IDs and distances.

### Exceptions

<AccordionGroup>
  <Accordion title="std::invalid_argument">
    * Throws if the query vectors have incompatible dimensions with the index.
    * Throws if the index was not created or loaded yet.
  </Accordion>

  <Accordion title="std::runtime_error">
    * Throws if the query could not be executed.
  </Accordion>
</AccordionGroup>

### Example Usage

```cpp theme={null}
cyborg::Array2D<float> queries{/*...*/}; // Populate with one or more query vectors
cyborg::QueryParams params(10, 5);  // top_k = 10, n_probes = 5

QueryResults results = index->Query(queries, params);
auto view = results[0]; // Access first query's results
for (uint32_t j = 0; j < view.num_results; ++j) {
    std::cout << "ID: " << view.ids[j] << ", Distance: " << view.distances[j] << std::endl;
}
```