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The RAG Obituary: Killed by agents, buried by context windows

nicolasbustamante.com

61–70 of 185 posts

Re: The RAG Obituary: Killed by agents, buried by context windows

#61

>The winners will not be the ones who maintain the biggest vector databases, but the ones who design the smartest agents to traverse abundant context and connect meaning across documents. So if one were building say a memory system for an AI chat bot, how would you save all the data related to a user? Mother's name, favorite meals, allergies? If not a Vector database like pinecone, then what? Just a big .txt file per…

Exactly. Just a markdown file per user. Anthropic recommends that.

Re: The RAG Obituary: Killed by agents, buried by context windows

#62
post #56
post #14

Earlier quoted context omitted.

I don’t mind articles that have a hint of “an AI helped write this” as long as the content is actually informationally dense and well explained. But this article is an obvious ad, has almost no interesting information or summaries or insights, and has the… weirdly chipper? tone that AI loves to glaze readers with.

Why call it an ad? It’s not even on the company site. I only mentioned my company upfront so people get context (why we had to build a complex RAG pipeline, what kinds of documents we’re working with, and why the examples come from real production use cases).

It stands out because the flow and tone was clearly AI generated. It’s fluff, and I don’t trust it was written by a human who wasn’t hallucinating the non-company related talking points.

Re: The RAG Obituary: Killed by agents, buried by context windows

#63
post #50

This glosses over a fundamental scaling problem that undermines the entire argument. The author's main example is Claude Code searching through local codebases with grep and ripgrep, then extrapolates this to claim RAG is dead for all document retrieval. That's a massive logical leap. Grep works great when you have thousands of files on a local filesystem that you can scan in milliseconds. But most enterprise RAG use…

Appreciate the feedback. I’m not saying grep replaces RAG. The shift is that bigger context windows let LLMs just read whole files, so you don’t need the whole chunk/embed pipeline anymore. Grep is just a quick way to filter down candidates. From there the model can handle 100–200 full docs and jot notes into a markdown file to stay within context. That’s a very different workflow than classic RAG.

That's fair, but how do you grep down to the right 100-200 documents from millions without semantic understanding? If someone asks "What's our supply chain exposure?" grep won't find documents discussing "vendor dependencies" or "sourcing risks."

You could expand grep queries with synonyms, but now you're reimplementing query expansion, which is already part of modern RAG. And doing that intelligently means you're back to using embeddings anyway.

The workflow works great for codebases with consistent terminology. For enterprise knowledge bases with varied language and conceptual queries, grep alone can't get you to the right candidates.

Re: The RAG Obituary: Killed by agents, buried by context windows

#64
We're processing tenders for the construction industry - this comes with a 'free' bucket sort from the start, namely that people practically always operate only on a single tender.

Still, that single tender can be on the order of a billion tokens. Even if the LLM supported that insane context window, it's roughly 4GB that need to be moved and with current LLM prices, inference would be thousands of dollars. I detailed this a bit more at https://www.tenderstrike.com/en/blog/billion-token-tender-ra...

And that's just one (though granted, a very large) tender.

For the corpus of a larger company, you'd probably be looking at trillions of tokens.

While I agree that delivering tiny, chopped up parts of context to the LLM might not be a good strategy anymore, sending thousands of ultimately irrelevant pages isn't either, and embeddings definitely give you a much superior search experience compared to (only) classic BM25 text search.

Re: The RAG Obituary: Killed by agents, buried by context windows

#65
post #50

Earlier quoted context omitted.

Appreciate the feedback. I’m not saying grep replaces RAG. The shift is that bigger context windows let LLMs just read whole files, so you don’t need the whole chunk/embed pipeline anymore. Grep is just a quick way to filter down candidates. From there the model can handle 100–200 full docs and jot notes into a markdown file to stay within context. That’s a very different workflow than classic RAG.

That's fair, but how do you grep down to the right 100-200 documents from millions without semantic understanding? If someone asks "What's our supply chain exposure?" grep won't find documents discussing "vendor dependencies" or "sourcing risks." You could expand grep queries with synonyms, but now you're reimplementing query expansion, which is already part of modern RAG. And doing that intelligently means you're ba…

Classical search

Re: The RAG Obituary: Killed by agents, buried by context windows

#66
post #50

Earlier quoted context omitted.

Appreciate the feedback. I’m not saying grep replaces RAG. The shift is that bigger context windows let LLMs just read whole files, so you don’t need the whole chunk/embed pipeline anymore. Grep is just a quick way to filter down candidates. From there the model can handle 100–200 full docs and jot notes into a markdown file to stay within context. That’s a very different workflow than classic RAG.

That's fair, but how do you grep down to the right 100-200 documents from millions without semantic understanding? If someone asks "What's our supply chain exposure?" grep won't find documents discussing "vendor dependencies" or "sourcing risks." You could expand grep queries with synonyms, but now you're reimplementing query expansion, which is already part of modern RAG. And doing that intelligently means you're ba…

the agent greps for the obvious term or terms, reads the resulting documents, discovers new terms to grep for, and the process repeats until its satisfied it has enough info to answer the question

> You could expand grep queries with synonyms, but now you're reimplementing query expansion, which is already part of modern RAG.

in this scenario "you" are not implementing anything - the agent will do this on its own

this is based on my experience using claude code in a codebase that definitely does not have consistent terminology

it doesn't always work but it seemed like you were thinking in terms of trying to get things right in a single grep when it's actually a series of greps that are informed by the results of previous ones

Re: The RAG Obituary: Killed by agents, buried by context windows

#67

Earlier quoted context omitted.

Do you agree that bickering over AI-generated vs. not AI-generated makes for dull discussion? Sliding sewing needles deep into my fingernail bed sounds more appealing than nagging over such minutiae.

It certainly makes a dull discussion, but frankly we need to have it. Post-AI HN is now a checkbox on a marketing plan - like a GitHub repository is - and I’m sick of being manipulated and sold to in one of the few forums that wasn’t gamed. It’s not minutiae, it’s an overarching theme that’s enshittifying the third places. Heck even having to discuss this is ruining it (yet here I am lol).

I hate to ruin the magic for you, but HN has been part of marketing plans long before AI.

Re: The RAG Obituary: Killed by agents, buried by context windows

#69

This glosses over a fundamental scaling problem that undermines the entire argument. The author's main example is Claude Code searching through local codebases with grep and ripgrep, then extrapolates this to claim RAG is dead for all document retrieval. That's a massive logical leap. Grep works great when you have thousands of files on a local filesystem that you can scan in milliseconds. But most enterprise RAG use…

Not to mention, unless you want to ship entire containers, you are beholden to the unknown quirks of tools on whatever system your agent happens to execute on. It's like taking something already nondeterministic and extremely risky and ceding even more control—let's all embrace chaos. Generative AI is here to stay, but I have a feeling we will look back on this period of time in software engineering as a sort of dark…

Mostly, i agree, except that the industry (from where I'm standing) has never done much else but sell itself to marketers and capital.

Re: The RAG Obituary: Killed by agents, buried by context windows

#70

>The winners will not be the ones who maintain the biggest vector databases, but the ones who design the smartest agents to traverse abundant context and connect meaning across documents. So if one were building say a memory system for an AI chat bot, how would you save all the data related to a user? Mother's name, favorite meals, allergies? If not a Vector database like pinecone, then what? Just a big .txt file per…

Any kind of database is far too efficient for an LLM, just take all your markdown and turn it into less markdown.
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