Vector Database

Prerequisite: To firmly grasp the foundational concepts of Memory Architecture in AI systems, please review Comprehensive AI-Native System Architecture. After solving the Agent communication challenge in Part 1, we must face the LLM’s greatest enemy: Context Window limits. Even the best Orchestrator is useless if Worker Agents forget the User’s initial request after just a few tool-calling turns. 2.1. The Context Window Problem and Why Agents “Forget” Large Language Models (LLMs) are inherently Stateless. Every time you send a prompt, the LLM rereads the entire text from beginning to end. ...

In Part 2: Data Ingestion & Atomic Chunking - Bringing Product Data into the AI Environment, we established a clean data synchronization pipeline from PostgreSQL to Qdrant via Kafka CDC. But the journey of building a standard e-commerce search engine has just begun. When a user enters: “Asus ROG Zephyrus G14 laptop under $1500 in stock” If using purely Dense Vector Search: The system might return other Asus ROG Zephyrus laptops priced at $2000, or even older out-of-stock models, because the Embedding model only understands general semantic similarity and cannot process strict mathematical comparisons (Hard Filters like price < 1500 and in_stock = true). If using purely Lexical Search (BM25): The system fails when the user searches by intent, such as “thin and light high-performance gaming laptop”, because these keywords do not appear directly in the product description text. The optimal solution for e-commerce is Hybrid Search — combining Dense Search (semantic understanding), Sparse Search/BM25 (exact keyword and SKU matching), and Filterable HNSW (high-performance hard attribute filtering). ...

Answer-first: Naive RAG works well for simple keyword queries on isolated documents. For complex, global questions spanning multiple entities, GraphRAG is superior as it builds a knowledge graph using LLMs. Enterprise implementations require combining change data capture (CDC) with vector search to keep graphs synchronized. What You’ll Learn That AI Won’t Tell You Schema design for knowledge graphs that speed up global enterprise RAG. Syncing GraphRAG knowledge bases in real-time using PostgreSQL WAL events. Most RAG (Retrieval-Augmented Generation) implementations look the same: chunk documents, embed them into vectors, store them in a vector database, retrieve by cosine similarity, and inject the top-K chunks into the LLM context. This works for simple document Q&A. It fails systematically for enterprise knowledge bases where the answer to a question depends not on a single document chunk, but on the relationships between dozens of interconnected entities. ...

Answer-first: Agentic E-commerce Search transforms traditional search from passive keyword matching to active shopping assistance using AI agents that understand complex queries, apply business logic filters, and provide personalized results in real-time. What You’ll Learn That AI Won’t Tell You Practical strategies for tuning vector search precision without bloating RAM. How to coordinate multiple AI search agents to prevent search query latency spikes. The search system is the beating heart of every e-commerce platform. If customers cannot find a product, they cannot buy it. However, as we move through 2026, user search behavior has evolved drastically from typing short, abrupt keywords (e.g., “men’s running shoes”) to submitting complex, goal-oriented queries (e.g., “find me a pair of men’s waterproof trail running shoes, size 42, under $100, that can be delivered by tomorrow”). Against these multifaceted intents, traditional search engines begin to show their limitations. ...