Is PostgreSQL ts_rank_cd a BM25 implementation?
No. PostgreSQL’s built-in ts_rank and ts_rank_cd use their documented ranking functions. BM25 requires a suitable additional implementation or search system.
Answered in
pgvector and Hybrid Search: When Keeping Retrieval in Postgres HelpsPostgres can combine vector and lexical retrieval with rank fusion, simplifying consistency without replacing every dedicated search system.
Read the full analysisOther questions this article answers
More system design & architecture questions
- Does a virtual display sandbox an agent?
- Can invisible text hijack a screenshot-only agent?
- Is MCP inherently stateless?
- Does MCP automatically secure an exposed tool?
- Does speculative decoding always double speed?
- What happens when a draft token is rejected?
- Does Wasm guarantee that untrusted code cannot escape?
- Does WASI 0.2 run arbitrary desktop Python or Bash unchanged?
Every answer on Crashtech is written by the editor of the article it comes from — never auto-summarised. Browse all answers or the System Design & Architecture beat.