My RAG Stack for Code Retrieval: pgvector HNSW + Metadata Filters + Reranking (and the Parts I Refuse to Guess About)

I sat down to write the pgvector section of this post—the HNSW index DDL, the reranker batching, the metadata filter shapes—and realized I kept reaching for the wrong file. The query I was proud of wasn’t the vector search. It was dedupeRagChunks. Th...