Querying an Index

This doc shows the classes that are used to query indices.

Main Query Classes

Querying an index involves three main components:

• Retrievers: A retriever class retrieves a set of Nodes from an index given a query.

• Response Synthesizer: This class takes in a set of Nodes and synthesizes an answer given a query.

• Query Engine: This class takes in a query and returns a Response object. It can make use of Retrievers and Response Synthesizer modules under the hood.

• Chat Engines: This class enables conversation over a knowledge base. It is the stateful version of a query engine that keeps track of conversation history.

Main query classes

• Retrievers
• Response Synthesizer
• Query Engines
• Chat Engines

Additional Query Classes

We also detail some additional query classes below.

• Query Bundle: This is the input to the query classes: retriever, response synthesizer,

  and query engine. It enables the user to customize the string(s) used for embedding-based query.

• Query Transform: This class augments a raw query string with

  associated transformations to improve index querying. Can be used with a Retriever (see TransformRetriever) or QueryEngine.

Additional query classes

• Query Bundle
• Query Transform