Postgres pgvector RAG Pipeline

PostgreSQL + pgvector uzerine uctan uca RAG pipeline chunking (recursive 1024/256 overlap vs…

An end-to-end RAG pipeline on PostgreSQL + pgvector covering every stage: chunking, embedding, indexing, retrieval, and quality evaluation. It makes the hard engineering decisions concrete: HNSW vs IVFFLAT, recursive vs semantic chunking, OpenAI vs multilingual embeddings: with cost ceilings, PII masking, and re-embed migration plans baked in. You get a production-grade semantic search layer instead of a fragile prototype.

$15 one-time
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Prices include 20% VAT. · Forged on real agency work · one-time, no lock-in

  • Type Skill
  • Category Data & Analytics
  • Delivery Email · instant
  • License One-time
Run preview
forgehouse, postgres-pgvector-rag-pipeline

Inside the run · no black box

See the actual work before you buy it.

Your RAG stack can live inside the Postgres you already run. From HNSW indexing to a weekly recall cron, retrieval gets built as a measured production system, not a demo notebook.

  1. Schema first: vector extension enabled, a documents table carrying an embedding_version column and JSONB metadata, an HNSW index at m=16 and ef_construction=64, a GIN index on metadata so filters never full-scan, and row-level security policies splitting admin from public chunks.
  2. Ingestion runs as chunk, mask, embed, upsert: recursive splitting at 1024 tokens with 256 overlap (semantic-boundary splitting for legal or financial documents), then PII masking BEFORE embedding, because once personal data is embedded it lives inside the vector space and cannot be removed. Embedding goes in batches of 64, insert is an upsert keyed on source file, chunk index and version.
  3. Retrieval applies three controls: cosine similarity with a 0.7 relevance threshold (below it the user gets an honest 'not found' instead of noise), ef_search set per query to trade latency against recall, and MMR diversity so one source file cannot dominate the top 5.
  4. A weekly evaluation cron scores recall@k, MRR and nDCG against 100+ human-labeled query pairs. A 10 percent recall drop fires an alarm, so quality drift is measured, not felt.
  5. Embedding model upgrades run blue-green: a parallel v2 column and index, dual-write on new inserts, background re-embedding in batches, and cutover only when v2 recall meets or beats v1. Zero downtime, full rollback path.
  6. Cost ceilings are wired in: storage at 80 percent of plan and monthly embedding spend over budget both trigger alerts before the bill does.
Use cases · what happens when you plug it in

One power source. 6 lines out.

postgres-pgvector-rag-pipeline · core

core active · 6 lines

  1. Building a semantic search layer for docs, blog, or support content

    ✓ building a semantic search
  2. Standing up a RAG chatbot retrieval backend

    ✓ standing up a rag chatbot
  3. Migrating an index from IVFFLAT to HNSW to raise recall

    ✓ migrating an index from
  4. Upgrading embedding models with zero-downtime re-embed

    ✓ upgrading embedding models
  5. Tuning recall vs latency with HNSW ef_search

    ✓ tuning recall vs latency
  6. Evaluating pipeline quality with recall@k, MRR, and nDCG

    ✓ evaluating pipeline qual…
Benefits · what you walk away with

Yours to keep.

Drag time forward. Watch what stays.

Forever

That's what owning means.

The rented stack

ai writing tool: subscription

expired · access lost

analytics suite: subscription

expired · access lost

design platform: subscription

expired · access lost

(nothing left)

Your forge

  1. Higher retrieval accuracy through deliberate chunking, indexing, and diversity (MMR) choices

    license: perpetual
  2. Predictable cost with embedding-token budgets and ceiling alarms

    license: perpetual
  3. Privacy-safe ingestion that masks personal data before embedding, when it can no longer be removed

    license: perpetual
  4. Confidence that quality is measured, not assumed, via scheduled evaluation

    license: perpetual

subscriptions expire · deeds don't

What's included · the full manifest

Everything in the box.

Pick a piece up. Watch it work.

pgvector schema with HNSW index, metadata GIN index, and embedding versioning

part 01 of 06 · in the box

6 parts · one working system · ships instantly by email

From the field · a real case

This wasn’t written at a desk.

The problem

The fix

The result

Who it's for

This wasn't forged for everyone.

  • Not for you if you'd rather rent a tool than own one.
  • Not for you if you want someone else to run your stack.
  • Not for you if you're happy guessing.
Still here? Good.

Backend and AI engineers building reliable, cost-controlled semantic search or RAG retrieval on PostgreSQL.

then this was forged for you.

Works with

Universal by design: these run in any AI. Delivered in the open Agent Skills + MCP format (native in Claude); ChatGPT, Gemini, Cursor and Copilot adapt the same files their own way.

  • Claude Native format
  • ChatGPT Adapts via open standards
  • Gemini Adapts via open standards
  • Cursor Adapts via open standards
  • Copilot Adapts via open standards
Questions · still in the air

Catch what's on your mind.

the air is clear. nothing between you and the forge.
catch a spark: the forge will answer

  1. Do I need Supabase, or does any PostgreSQL work?

    Any PostgreSQL with the pgvector extension works: the schema, HNSW indexing, ingestion pipeline, and evaluation harness are plain Postgres. Supabase appears in the cost-ceiling examples because it's a common managed host, not because anything depends on it.

  2. How do I know the retrieval actually works instead of just hoping?

    Quality is measured, not assumed: the evaluation harness computes recall@k, MRR, and nDCG against ground-truth queries on a schedule, and HNSW ef_search gives you an explicit recall-versus-latency dial. Index and chunking decisions are framed as measurable trade-offs, including the IVFFLAT-to-HNSW migration path.

  3. Does it include the chatbot or LLM answer layer?

    No. It ends where retrieval ends: chunking, PII masking, embedding, indexing, similarity search with MMR diversity, and evaluation. The generation layer that turns retrieved chunks into answers sits on top and is a separate concern.

  4. How is it delivered?

    By email right after purchase: ready to run, downloaded instantly, no setup wait.

  5. One-time or subscription?

    A one-time purchase; no subscription or hidden fees. VAT (20%) is included.

  6. Can I get a refund?

    As a digital product, it can’t be refunded once downloaded. That’s why we show exactly what’s inside and who it’s for, right here.