Hi Yufei, Persisting OSI data as Polaris entities sounds reasonable to me.
However, I believe the REST API layer for OSI should be structured as a module with opt in/out opportunities for downstream builds (similar to the Metric query API). This is not a feature flag concern, but a point about the composition of the Polaris code. A modular approach promotes code clarity and allows both including the new API into default Polaris images as well as flexibility downstream projects. I do not see any downside to the modular approach. Feature flags can certainly be supported in the new API modules. Cheers, Dmitri. On Mon, Jun 22, 2026 at 5:00 PM Yufei Gu <[email protected]> wrote: > Anand, thanks for chiming in. Looking forward to work together on it. > > Dmitri, Adam, Adnan, thanks for the clarification. I think we can separate > a few concerns here. > > Apache Ossie specifies the OSI model spec itself, but not the CRUD REST > endpoints for managing OSI documents in Polaris. Polaris has the > opportunity to define those APIs. As Adam mentioned, the validator is > intended for Ossie schema validation. That should definitely be version > based, so Polaris can validate the submitted document against the > corresponding OSI spec version while keeping the REST API contract under > Polaris control. > > On the "first class" point, I think Adnan's interpretation is correct. The > intent is that a semantic model is a Polaris entity in the same sense as an > Iceberg table, view, generic table, or policy. It participates in the > Polaris metadata model, authorization model, and lifecycle as a managed > entity. In that sense, it is different from metrics or events, which are > auxiliary data associated with entities rather than entities themselves. > > On the "always active" point, providing a feature flag makes sense, this is > already included in PR 4816. We can run the OSI API by default in the > Apache Polaris build, but allow downstream admins to turn it off if they do > not need it in their deployment. > > Thanks, > Yufei > > > On Mon, Jun 22, 2026 at 1:37 PM Anand Kumar Sankaran via dev < > [email protected]> wrote: > > > JB and Yufei, > > > > Thanks for doing this. We have customers asking for this as well. Happy > to > > help in any way possible. > > > > - > > Anand > > > > From: Adnan Hemani via dev <[email protected]> > > Date: Monday, June 22, 2026 at 12:18 PM > > To: [email protected] <[email protected]> > > Cc: Adnan Hemani <[email protected]> > > Subject: Re: [DISCUSS] Semantic Layer Support in Apache Polaris > > > > This Message Is From an External Sender > > This message came from outside your organization. > > Report Suspicious< > > > https://us-phishalarm-ewt.proofpoint.com/EWT/v1/Iz9xO38YGHZK!YhNDZAGomgiHL51L-6FL3QPZjxHXwiq6JCAQHbb6PAE7K6Eqwb--zyy23NolE2-B94Vu6rTO00mQ6c0S3xLY-wGl3G8wkj5qTIJjWF_iK7wIvcJej0eX1hsbj7Uhl7_c$ > > > > > > > > > Hi Adam, Dmitri, Yufei, > > > > Adding in a clarification: I believe "first class" in the context of OSI > > would mean that it is given the same level of importance as a Polaris > > entity as a Table or View would. Is that generally correct? > > > > Best, > > Adnan Hemani > > > > On Mon, Jun 22, 2026 at 10:50 AM Adam Christian < > > [email protected]> wrote: > > > > > Hi Dmitri, > > > > > > This proposal [1] includes a second tab with the detailed design. It > > shows > > > the REST APIs that handle the CRUD operations for OSI Semantic Models. > > The > > > Semantic Model will be validated in the OsiDocumentValidator which I > > assume > > > will validate against the Apache Ossie version. In my reading, Polaris > > does > > > not control it; we will leverage the upstream spec. > > > > > > Regarding OSI functionality if this feature is always active, I assume > > > users would benefit from it being active. If an admin user does not > want > > to > > > leverage OSI inside their Polaris instance, they simply won't grant the > > > privileges to the consuming users. > > > > > > [1] - > > > > > > > > > https://urldefense.com/v3/__https://docs.google.com/document/d/1ZdI-1w_5LbyCMhvUhLCtOt-N1Z89L2P-oiGLaYayCZg/edit?usp=sharing__;!!Iz9xO38YGHZK!5zRt5PLr106Rj8WbH_RftJ4SqCWP119n37Z77kzoNL-_JhobudorMvD0UdqyXJTi1PCMu0vGL3KGPBIq6oELUw$ > > > > > > On Thu, Jun 18, 2026 at 6:13 PM Dmitri Bourlatchkov <[email protected]> > > > wrote: > > > > > > > Hi Yufei, > > > > > > > > Sorry for getting to this proposal late. I postred some comments on > PR > > > > 4816, recounting the key points here in more detail. > > > > > > > > * From the proposal doc: Goal G1: "Store OSI 0.1.x documents as > > > first-class > > > > Polaris entities, scoped under a Namespace" > > > > > > > > I believe this needs a bit more discussion before we proceed to > > concrete > > > > code changes. The idea of persisting OSI data is totally valid. > > However, > > > > I'm not sure what "first class" means in this context? Does it mean > > that > > > > OSI functionality has to be active all the time? > > > > > > > > My initial perception of this proposal is that as a use case it is > > > similar > > > > to persisting Metrics (or Events) in Polaris. That is, the feature is > > > > valuable, but downstream projects may want to have the flexibility of > > > > deciding whether to include it or not. > > > > > > > > * Another point I'd like to clarity is about the REST API definition. > > Are > > > > API endpoints going be defined and controlled by the Polaris project? > > > > > > > > * Are REST API payload types defined and controlled by Polaris or by > > > Apache > > > > Ossie [1]? > > > > > > > > [1] > > > > > > > https://urldefense.com/v3/__https://www.mail-archive.com/[email protected]/msg86564.html__;!!Iz9xO38YGHZK!5zRt5PLr106Rj8WbH_RftJ4SqCWP119n37Z77kzoNL-_JhobudorMvD0UdqyXJTi1PCMu0vGL3KGPBLfgVHpkQ$ > > > > > > > > Thanks, > > > > Dmitri. > > > > > > > > On Fri, May 29, 2026 at 6:34 PM Yufei Gu <[email protected]> > wrote: > > > > > > > > > Hi folks, > > > > > > > > > > As AI agents, BI tools, notebooks, and query engines increasingly > > > consume > > > > > the same data, semantic definitions such as metrics and dimensions > > are > > > > > often duplicated across multiple systems. This leads to > inconsistent > > > > > definitions, duplicated effort, and governance challenges. The rise > > of > > > AI > > > > > agents further amplifies this problem, as agents rely on semantic > > > context > > > > > to understand data and reason about business concepts. Without a > > shared > > > > > semantic layer, organizations often end up maintaining multiple > > > versions > > > > of > > > > > the same business definitions across tools and applications. > > > > > > > > > > JB and I would like to start a discussion on adding semantic layer > > > > support > > > > > to Apache Polaris so semantic models can be defined once, governed > > > > > centrally, and consumed consistently across tools. The proposal[1] > > > > > introduces semantic models as a first class Polaris entity using > the > > > Open > > > > > Semantic Interchange (OSI)[2] specification[3]. At a high level, > the > > > > > proposal adds: > > > > > > > > > > - A new SEMANTIC_MODEL entity type > > > > > - CRUD APIs for semantic models > > > > > - Schema validation and authorization > > > > > > > > > > Polaris remains a metadata service and does not execute metrics or > > > > semantic > > > > > queries. > > > > > Feedback on the overall direction, design, and OSI adoption would > be > > > > > greatly appreciated. > > > > > > > > > > 1. > > > > > > > > > > > > > > > > > > > > https://urldefense.com/v3/__https://docs.google.com/document/d/1ZdI-1w_5LbyCMhvUhLCtOt-N1Z89L2P-oiGLaYayCZg/edit?usp=sharing__;!!Iz9xO38YGHZK!5zRt5PLr106Rj8WbH_RftJ4SqCWP119n37Z77kzoNL-_JhobudorMvD0UdqyXJTi1PCMu0vGL3KGPBIq6oELUw$ > > > > > 2. > > > https://urldefense.com/v3/__https://open-semantic-interchange.org__;!!Iz9xO38YGHZK!5zRt5PLr106Rj8WbH_RftJ4SqCWP119n37Z77kzoNL-_JhobudorMvD0UdqyXJTi1PCMu0vGL3KGPBKnqDA0QQ$ > > > > > 3. > > > > > > > > > > > > > > > > > > > > https://urldefense.com/v3/__https://github.com/open-semantic-interchange/OSI/blob/main/core-spec/spec.md__;!!Iz9xO38YGHZK!5zRt5PLr106Rj8WbH_RftJ4SqCWP119n37Z77kzoNL-_JhobudorMvD0UdqyXJTi1PCMu0vGL3KGPBLfoGUc7Q$ > > > > > > > > > > > > > > > Yufei > > > > > > > > > > > > > > > > > -- Dmitri Bourlatchkov Senior Staff Software Engineer, Dremio Dremio.com <https://www.dremio.com/?utm_medium=email&utm_source=signature&utm_term=na&utm_content=email-signature&utm_campaign=email-signature> / Follow Us on LinkedIn <https://www.linkedin.com/company/dremio> / Get Started <https://www.dremio.com/get-started/> The Agentic Lakehouse The only lakehouse built for agents, managed by agents
