Releases

DocArray v2 Release

Announcing the brand new rewrite of DocArray. If you're building a machine learning application that deals with multimodal data, then DocArray is the way to go

Engineering Group

Apr 20, 2023 • 4 min read

Release v0.30.0 (a.k.a DocArray v2)

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This version of DocArrray is a complete rewrite, therefore it includes several (more than breaking) changes. Be sure to check the documentation to prepare your migration.

Changelog

If you have been using recent versions of DocArray, you will already be familiar with its dataclass API.

DocArray v2 is that idea, taken seriously. Every Document is created through a dataclass-like interface, courtesy of Pydantic.

This has the following advantages:

Flexibility: No need to conform to a fixed set of fields -- your data defines the schema.
Multimodality: Easily store multiple modalities and multiple embeddings in the same Document.
Language agnostic: At their core, Documents are just dictionaries, and this makes it easy to create and send them from any language, not just Python.

You may also be familiar with our old Document Store for vector database integration. They are now called Document Indexes and offer the following improvements:

Hybrid search: You can now combine vector search with text search and even filter by arbitrary fields.
Production-ready: The new Document Indexes are a much thinner wrapper around the various vector DB libraries, making them more robust and easier to maintain.
Increased flexibility: We strive to support any configuration or setting you could perform through the vector DB's first-party client.

Document Indexes currently support Weaviate, Qdrant, ElasticSearch, and HNSWLib, with more to come.

Changes to `Document`

Document has been renamedBaseDoc.
BaseDoc cannot be used directly but instead has to be extended. Therefore, each document class is created through a dataclass-like interface.
Following from the previous point, extending BaseDoc allows for a flexible schema compared to the Document class in v1 which only allowed for a fixed schema, with one of tensor, text and blob, and additional chunks and matches.
Due to the added flexibility, one can not know what fields your document class will provide. Therefore, various methods from v1 (such as .load_uri_to_image_tensor()) are not supported in v2. Instead, we provide some of those methods on the typing level.
In v2, we have the LegacyDocument class, which extends BaseDoc while following the same schema as v1's Document. The LegacyDocument can be helpful to start migrating your codebase from v1 to v2. Nevertheless, the API is not fully compatible with DocArray v1 Document. Indeed, none of the methods associated with Document are present. Only the schema of the data is similar.

Changes to `DocumentArray`

DocList

The DocumentArray class from v1 has been renamed DocList. This better describes its actual functionality since it is a list of BaseDoc.

DocVec

Additionally, we have introduced the class DocVec, which is a column-based representation of BaseDoc. Both DocVec and DocList extend AnyDocArray.
DocVec is a container of Documents appropriate for computations that require batches of data (i.e., matrix multiplication, distance calculation, deep learning forward pass).
A DocVec has a similar interface to DocList but with an underlying implementation that is column-based instead of row-based. Each field of the schema of the DocVec (the .doc_type which is a BaseDoc) will be stored in a column. If the field is a tensor, the data from all Documents will be stored as a single doc_vec (Torch/TensorFlow/NumPy) tensor. If the tensor field is AnyTensor or a union of tensor types, the .tensor_type will be used to determine the type of the doc_vec column.

Parameterized DocList

Because you now have the flexibility to design your own document schema, when initializing a DocList, the contents do not have to all be of the same type.
If you want a homogenous DocList you can parameterize it at initialization time:

from docarray import DocList
from docarray.documents import ImageDoc

docs = DocList[ImageDoc]()

Methods like .from_csv() or .pull() only work with a parameterized DocList.

Access attributes of your DocumentArray

In v1, you could access an attribute of all Documents in your DocumentArray by calling the plural of the attribute's name on your DocArray instance.
In v2, you don't have to use the plural; instead, use the Document's attribute name since AnyDocArray it will expose the same attributes as the BaseDocs it contains. This will return a list of type(attribute). However, this works only if all the BaseDocs in the AnyDocArray have the same schema. Therefore only this works:

from docarray import BaseDoc, DocList


class Book(BaseDoc):
    title: str
    author: str = None


docs = DocList[Book]([Book(title=f'title {i}') for i in range(5)])
book_titles = docs.title  # returns a list[str]

# this would fail
# docs = DocList([Book(title=f'title {i}') for i in range(5)])
# book_titles = docs.title

Changes to Document Store

In v2, the Document Store has been renamed DocIndex and can be used for fast retrieval using vector similarity. DocArray v2 DocIndex supports:

Instead of creating a DocumentArray instance and setting the storage parameter to a vector database of your choice, in v2 you can initialize a DocIndex object of your choice, such as:

db = HnswDocumentIndex[MyDoc](work_dir='/my/work/dir')

Furthermore, DocStore in v2 can be used for simple long-term storage, such as with AWS S3 buckets or Jina AI Cloud.

Thank you to all of the contributors to this release:

Release v0.30.0 (a.k.a DocArray v2)

Changelog

Changes to Document

Changes to DocumentArray