A lakehouse holds the data and the compute, and it is very good at both. What it knows about meaning it works out from column names, table structure and what people queried before. That holds up until the rule governing the metric lives in a document the lakehouse has never read, which is most of the time.
This page sets out what Databricks is built for, the class of question inference cannot settle, how a governed context layer compares, and when you do not need one.
Databricks is a lakehouse: storage and compute in one place, with the engineering surface to build on top of it. Pipelines, notebooks, streaming, a technical catalog holding schemas, lineage and permissions, and a mature machine learning platform that a lot of serious work runs on. For processing data at scale it is an excellent product and this page is not an argument against buying one.
It also answers questions in natural language now, which is where the comparison actually starts. To do that, something has to decide which table and which column a question is about. That decision is made from the material available: the schema, the column names, the relationships, and what people have queried before. It is a reasonable way to make the decision and it works a surprising amount of the time.
The question this page is about is what happens the rest of the time, and how you would know which case you are in.
Ask for revenue by region.
There are four candidate tables. One is the finance-approved mart, refreshed monthly after close. Two are analyst-built copies from projects that ended. The fourth is a staging table that predates the others and, because it has been in every dashboard since, carries by far the most query history.
Inference ranks on usage, and usage points at the staging table. The answer comes back fast, formatted well, and built on the wrong source. Nobody notices, because the number is the right order of magnitude and there is no signal in the output that says which table produced it or that a different one was approved for the purpose.
Underneath that sits the harder version of the problem. Even the correct table does not carry the rule. That revenue excludes intercompany transactions, that returns booked after period close belong to the prior period, that one acquired entity reports on a different calendar: all of it was decided in documents, and none of it is inferable from a schema. A lakehouse can tell you what the data is. It was never asked to hold what the business decided it should mean.
| Databricks | Metagem | |
|---|---|---|
| What it holds | Tables, files, pipelines, models, and technical metadata over them | Terms, rules, processes, roles and the fields that carry them |
| Source coverage | What has been landed in the lakehouse | Structured and unstructured sources across the estate |
| Where meaning comes from | Inferred from schema, column names and query history | Extracted from documents and systems, then approved by an owner |
| Business rules and exceptions | Not modelled as such | First-class objects, with the fields they govern |
| Provenance | Lineage between assets | Each concept linked to its source document or field, and its approver |
| When meaning is ambiguous | Best guess, ranked | Flagged, clarified or refused |
| Runs queries and compute | Yes | No |
| Machine learning platform | Yes | No |
| Stores your data | Yes | No |
Read the last three rows first, because they are the ones that decide whether these are competing products. Databricks runs the compute, holds the data and trains the models. A context layer does none of the three and will never bid for the work. The row that actually separates them is where meaning comes from, and it is the only row on the table either product would fight over.
If everything material has been modelled into the lakehouse, the definitions are already agreed and encoded there, the governing rules live in the model rather than in documents, and the people asking questions are analysts who would spot a wrong number, the lakehouse and its catalog are proportionate. The layer earns its place when the rules are written in prose somewhere else, when the same term resolves differently in two systems, or when the thing consuming the answer will act on it without a human reading it first.
Approved definitions, the rules and exceptions around them, the roles accountable for them, and the mapping down to the fields that carry them, each traceable to where it came from.
No compute, no storage, no pipelines, no machine learning, no query execution and no text-to-SQL. It holds metadata about meaning and has no opinion on how fast your cluster is.
The lakehouse, the catalog, the notebooks, the ML platform and the analytics team's way of working. This sits beside all of it rather than underneath it.
The meaning a lakehouse cannot infer mostly comes from sources that are not in the lakehouse: policy documents, finance manuals, the specifications behind a process, the ERP two systems upstream. A context layer reads structured and unstructured sources alike, which is what lets a rule written in prose end up attached to the column it governs. And because it is not lakehouse-resident, the same governed meaning serves your BI tools, your agents and whatever you standardise on next, in open formats you keep.
Inference is a good default and a poor authority. Metagem supplies the definitions, rules and owners a lakehouse was never asked to hold, each one traceable to the document or field it came from.
The retrieval mechanism behind this is described on Graph-RAG, and the query boundary on semantic layer vs context layer.
We will show you what the context layer holds behind it: the approved definition, the rules and carve-outs, the owner, and the fields it resolves to.
Talk to our team