Metadata Filtering

We support rich filtering features of query results based on metadata fields. While joint vector and metadata search at scale presents a significant challenge, LanceDB achieves sub-100ms latency at thousands of QPS, enabling efficient vector search with filtering capabilities even on datasets containing billions of records.

By default, post-filtering is performed on the top-k results returned by the vector search. However, pre-filtering is also an option that performs the filter prior to vector search. This can be useful to narrow down on the search space on a very large dataset to reduce query latency.

We also support standard SQL expressions as predicates for filtering operations. It can be used during vector search, update, and deletion operations.