I did a pass over PR but I guess I'm a little skeptical on what notion of "preferences" truly gets us in the protocol. In case the endpoint is available but not enforced, my mental model is to just let the client make whatever choice it wants. If a server really thinks it's advantageous to use the remote planning, I'd think it'd just say server side planning is enforced. For the "momentary load" case, all a client would need to do is just handle the server throttling and fallback to a client side planning (don't think the protocol needs to expand just for that).
On Wed, Jan 7, 2026 at 11:28 AM Russell Spitzer <[email protected]> wrote: > I'm in agreement with Prashsant's current plan, I have no preference on > naming of Only vs Enforced" > > On Wed, Jan 7, 2026 at 4:42 AM Eduard Tudenhöfner < > [email protected]> wrote: > >> Instead of calling it "ONLY", maybe "ENFORCED" would be a better term? I >> think that would more naturally express the behavior without having to >> define what "ONLY" really means. >> >> On Wed, Dec 24, 2025 at 12:05 AM Prashant Singh <[email protected]> >> wrote: >> >>> *Hi everyone,* >>> >>> *JB:* Mostly yes, but it's more about what the server wants the client >>> to do. The server can indicate if it supports a mode or not via the >>> /v1/config endpoint at this point. >>> >>> *Russell:* Thank you for the thorough feedback! I think it is a great >>> idea to break the optional mode into *Prefer Client | Prefer Catalog*—it >>> really opens up a lot of interesting use cases. >>> >>> For example, the server might support planning but, due to momentary >>> load, wants the client to see if it's open to planning on the client side. >>> Similarly, an argument can be made that if the server has a table cached in >>> memory, it would prefer the client comes to the server. Earlier, with just >>> the optional value, we were simply falling back to server or client side >>> planning based on whether the server supported scan planning. Now, the >>> client can express its own overrides via catalog configs as well. >>> >>> Based on our offline discussion, I have incorporated the feedback into >>> the updated matrix [1] to document what the planning modes would be based >>> on the server response and client overrides: >>> >>> - >>> >>> *CLIENT_ONLY + CATALOG_ONLY* = FAIL >>> - >>> >>> *One "ONLY" + opposite "PREFERRED"* = ONLY wins >>> - >>> >>> *Both "PREFERRED"* = Client config wins >>> - >>> >>> *Client not configured* = Use server config or default >>> >>> I will update the reference implementation soon based on this. I would >>> love to know what other folks think! >>> >>> Best, >>> >>> Prashant Singh >>> >>> [1] https://github.com/apache/iceberg/pull/14867#issuecomment-3683989832 >>> >>> On Sat, Dec 20, 2025 at 1:26 PM Russell Spitzer < >>> [email protected]> wrote: >>> >>>> I can imagine one more >>>> >>>> >>>> (None - I would rename this) ClientOnly - Client can use Catalog >>>> Planning or Local Planning >>>> >>>> PreferClient - Client should use local planning, but the plan api is >>>> available for this table — I can only imagine this would be useful for a >>>> scenario where most clients are heavy and have the resources to do local >>>> planning (or engine distributed planning) but you still want to support >>>> lightweight clients which can’t really do planning themselves. >>>> >>>> PreferCatalog - Client should use the plan API, but credentials have >>>> been provided to enable local planning — This is probably a transitional >>>> state as we move from clients that only support local planning to those >>>> which can use the plan api. >>>> >>>> CatalogOnly - Clients are not provided with the credentials required to >>>> read the table from the Metadata.json alone. If they do not implement the >>>> scan plan API they should fail fast, otherwise they will fail when they >>>> attempt to load a manifest_list file — This is used in circumstances where >>>> the catalog is giving either file specific credentials or is protecting the >>>> delivered files in some way such that their contents has been specially >>>> redacted or something like that. >>>> >>>> >>>> I assume most catalogs will start with “ClientOnly” or “None” >>>> >>>> Then as Catalogs being to support planning API we will see most tables >>>> move to >>>> PreferCatalog with some perhaps extremely heavy or large tables staying >>>> as PreferClient or Client Only. >>>> >>>> Then catalogs with special protections may have some tables return >>>> CatalogOnly so they can either scope credentials more tightly or >>>> manipulate the files that the client actually has access to in some way. >>>> >>>> On Sat, Dec 20, 2025 at 1:09 AM Jean-Baptiste Onofré <[email protected]> >>>> wrote: >>>> >>>>> Hi Prashant >>>>> >>>>> It makes sense to me. I guess we are using Catalog properties to >>>>> indicate what the REST server supports to the client, right ? >>>>> I will take a look at the PR, but I like the idea. >>>>> >>>>> Regards >>>>> JB >>>>> >>>>> On Sat, Dec 20, 2025 at 12:53 AM Prashant Singh < >>>>> [email protected]> wrote: >>>>> >>>>>> Hey All, >>>>>> >>>>>> I wanted to bring up the discussion of introducing a concept of rest >>>>>> scan planning mode which would help the server to instruct the client on >>>>>> how to plan the table via loadTableResponse or config at table level >>>>>> override. >>>>>> There are three possible values which one could think of : >>>>>> 1. *None* : i.e plan it on the client side, this may be the table is >>>>>> too small and the additional rest request would add more overhead than >>>>>> benefit. >>>>>> 2. *Optional* : client can choose to plan it either locally or can >>>>>> trigger server side planning. >>>>>> 3. *Required* : client MUST do server side planning, the server >>>>>> could suggest this if it has better indexed the iceberg metadata or >>>>>> client >>>>>> is running on low resources or the table is protected. Server MAY choose >>>>>> whatever way required to enforce the client cant bypass this for example >>>>>> let's say don't vend cred as part of loadTable and only mint it part of >>>>>> planning completion this would mean if the client doesn't call plan >>>>>> table . >>>>>> >>>>>> I proactively have created a pull request [1], would love to know all >>>>>> your feedback either here or in the PR directly ! >>>>>> >>>>>> Wish you all a very happy Holidays, it has been great working with >>>>>> you all. >>>>>> >>>>>> [1] https://github.com/apache/iceberg/pull/14867 >>>>>> >>>>>> Best, >>>>>> Prashant Singh >>>>>> >>>>>
