v.25.5New Feature

Clickhouse vector search now supports both pre-filtering

Clickhouse vector search now supports both pre-filtering and post-filtering and provides related settings for finer control. (issue #78161). #79854 (Shankar Iyer).
ClickHouse vector search now supports both pre-filtering and post-filtering, allowing users to apply filters before and after the vector similarity search process.

Why it matters

This feature enhances vector search capabilities by enabling finer control through pre-filtering to reduce the search space before similarity computation, and post-filtering to refine results after the search. It improves query performance and result relevance in use cases involving large datasets and complex filtering needs.

How to use it

Users can apply pre-filtering and post-filtering by specifying appropriate filtering conditions in their vector search queries. The new settings allow configuring these filters to control the scope and quality of vector search results.