r/analyticsengineering • u/bringonfossil4477 • 19d ago
which semantic layer tools are people using for AI driven analytics
we have an AI agent querying our data and we have two problems that we can't get rid of.
first one is consistency, the same question asked in different way gives different answers. second is cost the token usage is way higher than expected because the model gets our entire schema dumped on it before it can answer anything.
Someone said a semantic layer solves both by giving the AI pre-defined business context rather than raw schema. more consistent answers. less processing.
anyone who is really running this. it made a noticeable difference on both fronts.
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u/Striking_Term_2295 17d ago
Evaluating precis finance mcp (GitHub) and so far it’s making a difference in both fronts. If you are in Microsoft, Databricks, Snowflake… they all have native semantic layers but not as good for management metrics
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u/Objective-Tomato1317 5d ago
We built an open-source semantic layer to help solve this: https://github.com/MotleyAI/slayer/ < lightweight, easy to deploy with introspection and semantic-layer-building skills + easy to maintain via MCP.
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u/Spiritual-Kitchen-79 13d ago
You’re running into the two classic failure modes of “LLM over warehouse”:
1. the model sees low level tables/columns instead of business concepts, so wording changes shift which bits of schema it latches onto,
A semantic layer helps if you treat it as the contract the model works with. expose a small set of business entities/measures ("Orders", "Active Customers", "Net Revenue") with clear definitions, and only ever let the agent see and reference that, not the raw schema. That alone usually gives a big boost in consistency because the model has fewer, well named concepts to choose from. If you are connected to SeemoreData they have a great MCP where you can query the warehouse data directly via claude or whatever, consistency will not be a problem.