Hi Alex, Re: config property mixing, my concern is not so much about prefix vs. non-prefix config, but more about credentials vs. non-credentials configuration.
I believe distinguishing them at the API level will help implementations treat them correctly too. Conversely, mixing credentials with other config increases the chance of mis-handling them on the client side (e.g. logging when they are not supposed to be logged). Your point about the fact that these properties will eventually be mixed on the client side is quite valid. Therefore, I will not insist on separating credential properties from ordinary config in the API. However, if the properties are mixed we should not use the name "StorageAccessCredential" (note the last word) for their container, because that (IMHO) would actually make the API spec confusing. I'd suggest naming the container "StorageAccessConfiguration" (other names are welcome too). Re: well-structured properties objects - after thinking about it some more, I believe your points about client compatibility prevail. I'd think clients should be able to hangle new / unknown JSON properties, but it would certainly be an overhead in many cases. I'm fine using a generic property bag as the type at the API level. I still believe we should document exact property names in the spec. For that matter I propose moving property descriptions from Open API _comments_ to Open API _description_ fields. This way, notes about property meaning will not be lost after automated processing of the spec (e.g. by SwaggerHub). WDYT? Thanks, Dmitri. On Mon, Feb 23, 2026 at 7:27 AM Alexandre Dutra <[email protected]> wrote: > Hi all, > > > I do not think it is correct to mix the former with the latter. > > I don't think mixing general and prefix-specific configurations is > inherently incorrect—it's a grey area. However, I agree that it is > likely better practice to separate them. I believe the sensitivity > level of the configuration should not be the deciding factor, as any > configuration in a LoadTable response should be treated as sensitive. > > In Iceberg, the distinction in `LoadTableResult` between `config` and > `storage-credentials.config` is primarily one of scope: the former > applies broadly to the entire FileIO, and the latter is specific to an > S3 client tied to a particular prefix. It's important to note, though, > that any table-wide properties are ultimately merged with > prefix-specific properties when the S3 client is created [1]. > > > Open API can be leveraged to report them as well-structured objects > (JSON) > > The idea is interesting, especially since we control the specification > and thus know the supported properties. > > However, this approach may complicate the evolution of the > specification. Our guidance on evolution [2] states that new releases > of Polaris should maintain compatibility with older clients. This > requires that any addition or deprecation of properties must be done > in a backward-compatible way. Removing or renaming properties would > necessitate a major version bump for the specification. I am not > convinced that the potential benefits outweigh these consequences. > > Thanks, > Alex > > [1]: > https://github.com/apache/iceberg/blob/fec9800bcc0c4073ca727f3b3bfdc2f34abb26a3/aws/src/main/java/org/apache/iceberg/aws/s3/S3FileIO.java#L411-L415 > [2]: https://polaris.apache.org/releases/1.3.0/evolution/ > > > On Sat, Feb 21, 2026 at 1:12 AM Dmitri Bourlatchkov <[email protected]> > wrote: > > > > Hi All, > > > > I'm transferring some points from my GH comments [3826] here, for a wider > > discussion. > > > > 1) Apparently some of the response properties relate to actual > credentials > > (key, expiry time), while others are more general configuration items > (e.g. > > the refresh endpoint). > > > > I do not think it is corrent to mix the former with the latter. Primarily > > because of their different leak sensitivity levels but also because > > `StorageAccessCredential` are provided as a list, and I wonder why we > would > > want to send multiple endpoint config entries (one for each location > > prefix). > > > > 2) Currently properties are defined as an unstructured bag of key/value > > pair. I think Open API can be leveraged to report them as well-structured > > objects (JSON). > > > > Server code changes are required to add suport for new properties anyway. > > It should not be too difficult to evolve the Open API types at the > > same time. We've done it many times already (e.g. to support non-AWS S3 > > storage). > > > > WDYT? > > > > Thanks, > > Dmitri. > > > > [3826] https://github.com/apache/polaris/pull/3826/changes#r2829649503 > > > > On Sat, Feb 7, 2026 at 1:07 AM Jack Ye <[email protected]> wrote: > > > > > > How are clients supposed to know the meaning of credential > properties in > > > the "config" section? > > > > > > I think the contract is clear: since we are using the Iceberg REST > model > > > for StorageCredential, it must use the same configurations as the > Iceberg > > > credentials vending-related ones [1]. > > > > > > Based on the current Polaris implementation [2], the full list of > configs > > > is probably the following: > > > > > > S3: > > > Credentials: > > > - s3.access-key-id - AWS access key ID > > > - s3.secret-access-key - AWS secret access key > > > - s3.session-token - Temporary STS session token > > > - s3.session-token-expires-at-ms - Token expiration timestamp (ms) > > > Extra Properties: > > > - s3.endpoint - S3 endpoint URI (optional) > > > - s3.path-style-access - Path-style access flag (optional) > > > - client.region - AWS region > > > - aws.refresh-credentials-endpoint - Credential refresh endpoint > > > (optional) > > > > > > GCS: > > > Credentials: > > > - gcs.oauth2.token - Downscoped OAuth2 access token > > > - gcs.oauth2.token-expires-at - Token expiration timestamp (ms) > > > Extra Properties: > > > - gcs.oauth2.refresh-credentials-endpoint - Credential refresh > endpoint > > > (optional) > > > > > > Azure: > > > Credentials: > > > - adls.sas-token.<hostname> - SAS token keyed by storage account > hostname > > > - adls.sas-token-expires-at-ms.<hostname> - SAS token expiration (ms) > > > Extra Properties: > > > - adls.refresh-credentials-endpoint - Credential refresh endpoint > > > (optional) > > > > > > It would be helpful to specify those at least in the generic tables > spec, > > > ideally also in the Iceberg REST spec, which currently only lists S3 > > > configs and is already outdated. > > > > > > Best, > > > Jack Ye > > > > > > [1] > > > > > > > https://github.com/apache/polaris/blob/main/spec/iceberg-rest-catalog-open-api.yaml#L3299C1-L3306C1 > > > [2] > > > > > > > https://github.com/apache/polaris/blob/main/polaris-core/src/main/java/org/apache/polaris/core/storage/StorageAccessProperty.java > > > > > > > > > On Fri, Feb 6, 2026 at 11:03 AM Eric Maynard <[email protected] > > > > > wrote: > > > > > > > > How are clients supposed to know the meaning of credential > properties > > > in > > > > the "config" section? > > > > > > > > How are clients supposed to know the meaning of *any* properties > written > > > to > > > > a generic table? > > > > > > > > That clients need to interpret the payload of a generic table > response is > > > > already intrinsic to the generic table design. True, adding > credential > > > > vending pushes generic table support towards the service being > slightly > > > > more opinionated about the generic table metadata (i.e. the location > is > > > now > > > > implied to be a place that may require credentials to access) but as > this > > > > would be an opt-in for your generic tables I don't see this as a > blocking > > > > issue. > > > > > > > > --EM > > > > > > > > On Fri, Feb 6, 2026 at 10:57 AM Dmitri Bourlatchkov < > [email protected]> > > > > wrote: > > > > > > > > > Hi Yun, > > > > > > > > > > The proposal looks reasonable to me in general after a quick > review of > > > > the > > > > > doc. > > > > > > > > > > I have one concern, though, which may be a whole can of worms, I'm > > > afraid > > > > > :) > > > > > > > > > > How are clients supposed to know the meaning of credential > properties > > > in > > > > > the "config" section? The doc proposes to define it as a generic > > > property > > > > > bag. > > > > > > > > > > The example appears to use properties that Iceberg (java?) clients > > > might > > > > > use in a similar situation. However, the Generic Tables API is not > > > > related > > > > > to Iceberg in any way (AFAIK). > > > > > > > > > > Plus, I do not think these properties are well-defined even in > Iceberg > > > > > specifications. > > > > > > > > > > WDYT? > > > > > > > > > > Thanks, > > > > > Dmitri. > > > > > > > > > > On Fri, Feb 6, 2026 at 1:29 PM yun zou <[email protected] > > > > > > wrote: > > > > > > > > > > > Hi All, > > > > > > > > > > > > Generic Tables have been available since Polaris 1.0.0 and have > seen > > > > > > growing interest from an increasing number of customers. > > > > > > > > > > > > However, the current Generic Table capability has some > limitations. > > > One > > > > > > key gap is the lack of credential vending support. Without > credential > > > > > > vending, query engines must access tables using long-lived, > static > > > > cloud > > > > > > credentials configured directly in the engine runtime, which > limits > > > > both > > > > > > usability and security. > > > > > > > > > > > > To address this, we propose adding credential vending support for > > > > Generic > > > > > > Tables. This enhancement would allow a Polaris catalog to > dynamically > > > > > vend > > > > > > short-lived, scoped storage credentials to query engines at > runtime > > > > when > > > > > > accessing Generic Tables. > > > > > > > > > > > > The goals of this proposal are to: > > > > > > > > > > > > 1. > > > > > > > > > > > > Enable credential vending support for Generic Tables in > Polaris > > > > > > 2. > > > > > > > > > > > > Deliver an end-to-end experience for currently supported table > > > > > > formats, including Delta, Hudi, and Lance > > > > > > 3. > > > > > > > > > > > > Maintain consistency with the existing Iceberg credential > vending > > > > > model > > > > > > > > > > > > Please find the attached short design document with additional > > > details. > > > > > We > > > > > > would appreciate your review and valuable feedback. > > > > > > > > > > > > link to google doc: > > > > > > > > > > > > > > > > > > > https://docs.google.com/document/d/1QzTx4tcS23_mF-gc77GbTqtwuRHY5f_Aa_6E4VSKFU4/edit?tab=t.0#heading=h.rpqtaz73xt4v > > > > > > > > > > > > Best Regards, > > > > > > > > > > > > Yun > > > > > > > > > > > > > > > > > > >
