Meta Platforms, Inc.
Similarity search using progressive inner products and bounds

Abstract:

In one embodiment, a method includes receiving a query and determining a query vector. The method includes accessing multiple object vectors representing multiple objects, respectively. The method includes, for a first set of object vectors identified as top object vectors, calculating an inner product with the query vector. The method includes progressively computing an inner product of the query vector and each remaining object vector and sending, to a user, the objects corresponding to the top object vectors. Progressively computing an inner product includes checking whether to calculate a first partial inner product based on a bound on the inner product and the minimum inner product for a top object vector, calculating subsequent partial inner products until the inner product is complete, and substituting the object vector for a top object vector if the complete inner product is greater than the minimum inner product.