~/talk

Supercharged Search with Semantic Search and Vector Embeddings

Talkat NDC Copenhagen 2025 · 2025-09-08..09-12· [ai-assisted-development]
slides:none on file

Demonstrates building semantic search by generating 384‑dim and 1,124‑dim embeddings with OpenAI or local Olama via Microsoft.Extensions.AI, storing them in SQL Server 2025 vector type and querying with EF Core, then adding a DiskANN index for ANN. Uses 50,000 news rows; in‑memory kNN is ~100 ms, plain DB scan ~300 ms, and indexed ANN drops below ~50 ms while keeping ~95% recall. Code and demos show end‑to‑end generation, storage, and measured query times.

AI-written summary · about

  1. 0:00Semantic search and embeddings
  2. 1:05Lexical vs semantic search
  3. 3:16Semantic search with LLMs
  4. 8:08Storing vector embeddings
  5. 17:53Vector databases and SQL Server
  6. 23:13Demo: Embeddings for news
  7. 26:29In-memory semantic search
  8. 30:08SQL Server vectors with C#
  9. 37:27Vector indexing and ANN
  10. 43:59Evaluating ANN recall
  11. 49:05Demo: Speed comparison
  12. 50:44Multilingual semantic search
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