> > Of course we also need threads that express our preferences (voting). I > would suggest to keep these separate from discussions about single points > so that they can be persisted in the document.
Not sure if it helpful, but I added voting chips Question 0, as maybe an easier way to keep track of votes. If it is helpful, I can add them in other places that still need a vote (I think one needs a paid Google Docs account to insert them). Thanks, Micah On Wed, Feb 21, 2024 at 10:23 AM Szehon Ho <szehon.apa...@gmail.com> wrote: > Thanks Jan. +1 on having just one thread per question for > vote/preference. Where do you suggest we have it, on the discussion > question itself? It would be to keep the existing threads and move it > there. > > Also, I think it makes sense with making a slack channel (for quick > question, reply) , and also discuss unresolved questions in the next week's > sync or a separate meeting. > > On Wed, Feb 21, 2024 at 12:40 AM Jan Kaul <jank...@mailbox.org.invalid> > wrote: > >> Thank you Jack for driving the consensus for the MV spec and thank you >> all for the discussion. >> >> I really like the idea about incremental consensus because we often loose >> sight in detailed discussions. As Jack mentioned, the highest priority >> question currently is: >> >> *Should the Iceberg MV be realized as a view + storage table or do we >> define a new metadata format? *To have one place for the discussion, I >> created another Question ( >> https://docs.google.com/document/d/1UnhldHhe3Grz8JBngwXPA6ZZord1xMedY5ukEhZYF-A/edit?pli=1#heading=h.y70rtfhi9qxi) >> to the Materialized View Spec google document. >> >> To improve the visibility of the arguments I would like to propose a new >> process. It would be great if all relevant information is stored in the >> document itself. Therefore I would suggest to use the comment threads for >> smaller, temporary discussions which can be resolved by adding the points >> to the main document. Please close the threads if the information was added >> to the document. Additionally, I gave you all permissions to edit the >> documents, so you can add missing points yourselves. >> >> Of course we also need threads that express our preferences (voting). I >> would suggest to keep these separate from discussions about single points >> so that they can be persisted in the document. >> >> After a phase of collecting arguments for the different designs I think >> it would make sense to have video call to have a face to face discussion. >> >> What do you think? >> >> Best wishes, >> >> Jan >> On 20.02.24 21:32, Manish Malhotra wrote: >> >> Very excited for MV to be in Iceberg :) >> Keeping in the same doc. would be helpful, to have the trail. >> But also agreed, if there are too many directions/threads, then keep >> closing the old one, if there are no more questions. >> And put down the assumptions for the initial version to move forward. >> >> >> On Tue, Feb 20, 2024 at 12:17 PM Walaa Eldin Moustafa < >> wa.moust...@gmail.com> wrote: >> >>> I would vote to keep a log in the doc with open questions, and keep the >>> doc updated with open questions as they arise/get resolved. >>> >>> On Tue, Feb 20, 2024 at 11:37 AM Jack Ye <yezhao...@gmail.com> wrote: >>> >>>> Thanks for the response from everyone! >>>> >>>> Before proceeding further, I see a few people referring back to the >>>> current design from Jan. I specifically raised this thread based on the >>>> information in the doc and a few latest discussions we had there. Because >>>> there are many threads in the doc, and each thread points further to other >>>> discussion threads in the same doc or other doc, it is now quite hard to >>>> follow and continue discussing all different topics there. >>>> >>>> I hope we can make incremental consensus of the questions in the doc >>>> through devlist, because it provides more visibility, and also a single >>>> thread instead of multiple threads going on at the same time. If we think >>>> this format is not effective, I propose that we create a new mv channel in >>>> Iceberg Slack workspace, and people interested can join and discuss all >>>> these points directly. What do we think? >>>> >>>> Best, >>>> Jack Ye >>>> >>>> >>>> >>>> On Mon, Feb 19, 2024 at 6:03 PM Szehon Ho <szehon.apa...@gmail.com> >>>> wrote: >>>> >>>>> Hi, >>>>> >>>>> Great to see more discussion on the MV spec. Actually, Jan's document >>>>> "Iceberg >>>>> Materialized View Spec" >>>>> <https://docs.google.com/document/d/1UnhldHhe3Grz8JBngwXPA6ZZord1xMedY5ukEhZYF-A> >>>>> has >>>>> been organized , with a "Design Questions" section to track these debates, >>>>> and it would be nice to centralize the debates there, as Micah mentions. >>>>> >>>>> For Dan's question, I think this debate was tracked in "Design Question >>>>> 3: Should the storage table be registered in the catalog?". I think the >>>>> general idea there was to not expose it directly via Catalog as it is then >>>>> exposed to user modification. If the engine wants to access anything about >>>>> the storage table (including audit and storage), it is of course there via >>>>> the storage table pointer. I think Walaa's point is also good, we could >>>>> expose it as we expose metadata tables, but I am still not sure if there >>>>> is >>>>> still some use-cases of engine access not covered? >>>>> >>>>> It is true that for Jack's initial question (Do we really want to go >>>>> with the MV = view + storage table design approach for Iceberg MV?), >>>>> unfortunately we did not capture it as a "Design Question" in Jan's doc, >>>>> as >>>>> it was an implicit assumption of 'yes', because it is the choice of Hive, >>>>> Trino, and other engines , as others have pointed out. >>>>> >>>>> Jack's point about potential evolution of MV (like to add >>>>> partitioning) is an interesting one, but definitely hard to grasp. I >>>>> think >>>>> it makes sense to add this as a separate Design Question in the doc, and >>>>> add the options. This will allow us to flesh out this alternative >>>>> option(s). Maybe Micah's point about modifying existing proposal to >>>>> 'embed' the required table metadata fields in the existing view metadata, >>>>> is one middle ground option. Or we add a totally new MV object spec for >>>>> MV, separate than existing View spec? >>>>> >>>>> Also , as Jack pointed out, it may make sense to have the REST / >>>>> Catalog API proposal in the doc to educate the above decision. >>>>> >>>>> Thanks >>>>> Szehon >>>>> >>>>> On Mon, Feb 19, 2024 at 4:08 PM Walaa Eldin Moustafa < >>>>> wa.moust...@gmail.com> wrote: >>>>> >>>>>> I think it would help if we answer the question of whether an MV is a >>>>>> view + storage table (and degree of exposing this underlying >>>>>> implementation) in the context of the user interfacing with those >>>>>> concepts: >>>>>> >>>>>> For the end user, interfacing with the engine APIs (e.g., through >>>>>> SQL), materialized view APIs should be almost the same as regular view >>>>>> APIs >>>>>> (except for operations specific to materialized views like REFRESH >>>>>> command >>>>>> etc). Typically, the end user interacts with the (materialized) view >>>>>> object >>>>>> as a view, and the engine performs the abstraction over the storage >>>>>> table. >>>>>> >>>>>> For the engines interfacing with Iceberg, it sounds the correct >>>>>> abstraction at this layer is indeed view + storage table, and engines >>>>>> could >>>>>> have access to both objects to optimize queries. >>>>>> >>>>>> So in a sense, the engine will ultimately hide most of the >>>>>> storage detail from the end user (except for advanced users who want to >>>>>> explicitly access the storage table with a modifier like >>>>>> "db.view.storageTable" -- and they can only read it), while Iceberg will >>>>>> expose the storage details to the engine catalog to use it in scans if >>>>>> needed. So the storage table is hidden or exposed based on the >>>>>> context/the >>>>>> actual users. From Iceberg point of view (which interacts with the >>>>>> engines), the storage table is exposed. Note that this does not >>>>>> necessarily mean that the storage table is registered in the catalog with >>>>>> its own independent name (e.g., where we can drop the view but keep the >>>>>> storage table and access it from the catalog). Addressing the storage >>>>>> table >>>>>> using a virtual namespace like "db.view.storageTable" sounds like a good >>>>>> middle ground. Anyways, end users should not need to directly access the >>>>>> storage table in most cases. >>>>>> >>>>>> Thanks, >>>>>> Walaa. >>>>>> >>>>>> On Mon, Feb 19, 2024 at 3:38 PM Micah Kornfield < >>>>>> emkornfi...@gmail.com> wrote: >>>>>> >>>>>>> Hi Jack, >>>>>>> >>>>>>> >>>>>>>> In my mind, the first key point we all need to agree upon to move >>>>>>>> this design forward is*: Do we really want to go with the MV = >>>>>>>> view + storage table design approach for Iceberg MV?* >>>>>>> >>>>>>> >>>>>>> I think we want this to the extent that we do not want to redefine >>>>>>> the same concept with different representations/naming to the greatest >>>>>>> degree possible. This is why borrowing the concepts from the view (e.g. >>>>>>> multiple ways of expressing the same view logic in different dialects) >>>>>>> and >>>>>>> aspects of the materialized data (e.g. partitioning, ordering) feels >>>>>>> most >>>>>>> natural. IIUC your proposal, I think you are saying maybe two >>>>>>> modifications to the existing proposals in the document: >>>>>>> >>>>>>> 1. No separate storage table link, instead embed most of the >>>>>>> metadata of the materialized table into the MV document (the exception >>>>>>> seems to be snapshot history) >>>>>>> 2. For snapshot history, have one unified history specific to the >>>>>>> MV. >>>>>>> >>>>>>> This seems fairly reasonable to me and I think I can solve some >>>>>>> challenges with the existing proposal in an elegant way. If this is >>>>>>> correct (or maybe if it isn't quite correct) perhaps you can make >>>>>>> suggestions to the document so all of the trade-offs can be discussed in >>>>>>> one place? >>>>>>> >>>>>>> I think the one thing the current draft of the materialized view >>>>>>> ignores is how to store algebraic summaries (e.g. separate sum and count >>>>>>> for averages, or other sketches), so that new data can be incrementally >>>>>>> incorporated. But representing these structures feels like it >>>>>>> potentially >>>>>>> has value beyond just MVs (e.g. it can be a natural way to express >>>>>>> summary >>>>>>> statistics in table metadata), so I think it deserves at least a try in >>>>>>> incorporating the concepts in the table specification, so the >>>>>>> definitions >>>>>>> can be shared. I was imagining this could come as part of the next >>>>>>> revision of MV specification. >>>>>>> >>>>>>> The MV internal structure could evolve in a way that works more >>>>>>>> efficiently with the reduced scope of functionalities, without relying >>>>>>>> on >>>>>>>> table to offer the same capabilities. I can at least say that is true >>>>>>>> based >>>>>>>> on my internal knowledge of how Redshift MVs work. >>>>>>> >>>>>>> >>>>>>> I'm not sure I fully understand this point, but it seems the main >>>>>>> question here is what would break if it started to evolve in this >>>>>>> direction. Is it purely additive or do we suspect some elements would >>>>>>> need >>>>>>> to be removed? My gut feeling here is the main concerns here are >>>>>>> getting >>>>>>> the cardinatities correct (i.e. 1 MV should probably have 0, 1 or more >>>>>>> materialized storage tables associated with it, to support more advanced >>>>>>> algebraic structures listed above, and perhaps a second without them, >>>>>>> and >>>>>>> additional metadata to distinguish between these two different modes). >>>>>>> >>>>>>> If after the evaluation, we are confident that the MV = view + >>>>>>>> storage table approach is the right way to go, then we can debate the >>>>>>>> other >>>>>>>> issues, and I think the next issue to reach consensus should be >>>>>>>> "Should the >>>>>>>> storage table be registered in the catalog?". >>>>>>> >>>>>>> >>>>>>> I actually think there are actually more fundamental questions posed: >>>>>>> 1. Should be considering how items should be modelled in the REST >>>>>>> API concurrently with the Iceberg spec, as that potentially impacts >>>>>>> design >>>>>>> decision (I think the answer is yes, and we should update the doc with >>>>>>> sketches on new endpoints and operations on the endpoints to ensure >>>>>>> things >>>>>>> align). >>>>>>> 2. Going forward should new aspects of Iceberg artifacts rely on >>>>>>> the fact that a catalog is present and we can rely on a naming >>>>>>> convention >>>>>>> for looking up other artifacts in a catalog as pointers (I lean yes on >>>>>>> this, but I'm a little bit more ambivalent). >>>>>>> >>>>>>> Thanks, >>>>>>> Micah >>>>>>> >>>>>>> On Mon, Feb 19, 2024 at 12:52 PM Jack Ye <yezhao...@gmail.com> >>>>>>> wrote: >>>>>>> >>>>>>>> I suggest we need a step-by-step process to make incremental >>>>>>>> consensus, otherwise we are constantly talking about many different >>>>>>>> debates >>>>>>>> at the same time. >>>>>>>> >>>>>>>> In my mind, the first key point we all need to agree upon to move >>>>>>>> this design forward is*: Do we really want to go with the MV = >>>>>>>> view + storage table design approach for Iceberg MV?* >>>>>>>> >>>>>>>> I think we (at least me) started with this assumption, mostly >>>>>>>> because this is how Trino implements MV, and how Hive tables store MV >>>>>>>> information today. But does it mean we should design it that way in >>>>>>>> Iceberg? >>>>>>>> >>>>>>>> Now I look back at how we did the view spec design, we could also >>>>>>>> say that we just add a representation field in the table spec to store >>>>>>>> view, and an Iceberg view is just a table with no data but with >>>>>>>> representations defined. But we did not do that. So it feels now quite >>>>>>>> inconsistent to say we want to just add a few fields in the table and >>>>>>>> view >>>>>>>> spec to call it an Iceberg MV. >>>>>>>> >>>>>>>> If we look into most of the other database systems (e.g. Redshift, >>>>>>>> BigQuery, Snowflake), they never expose such implementation details >>>>>>>> like >>>>>>>> storage table. Apart from being close-sourced systems, I think it is >>>>>>>> also >>>>>>>> for good technical reasons. There are many more things that a table >>>>>>>> needs >>>>>>>> to support, but does not really apply to MV. The MV internal structure >>>>>>>> could evolve in a way that works more efficiently with the reduced >>>>>>>> scope of >>>>>>>> functionalities, without relying on table to offer the same >>>>>>>> capabilities. I >>>>>>>> can at least say that is true based on my internal knowledge of how >>>>>>>> Redshift MVs work. >>>>>>>> >>>>>>>> I think we should fully evaluate both directions, and commit to one >>>>>>>> first before debating more things. >>>>>>>> >>>>>>>> If we have a new and independent Iceberg MV spec, then an Iceberg >>>>>>>> MV is under-the-hood a single object containing all MV information. It >>>>>>>> has >>>>>>>> its own name, snapshots, view representation, etc. I don't believe we >>>>>>>> will >>>>>>>> be blocked by Trino due to its MV SPIs currently requiring the >>>>>>>> existence of >>>>>>>> a storage table, as it will just be a different implementation from the >>>>>>>> existing one in Trino-Iceberg. In this direction, I don't think we >>>>>>>> need to >>>>>>>> have any further debate about pointers, metadata locations, storage >>>>>>>> table, >>>>>>>> etc. because everything will be new. >>>>>>>> >>>>>>>> If after the evaluation, we are confident that the MV = view + >>>>>>>> storage table approach is the right way to go, then we can debate the >>>>>>>> other >>>>>>>> issues, and I think the next issue to reach consensus should be >>>>>>>> "Should the >>>>>>>> storage table be registered in the catalog?". >>>>>>>> >>>>>>>> What do we think? >>>>>>>> >>>>>>>> -Jack >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On Mon, Feb 19, 2024 at 11:32 AM Daniel Weeks <dwe...@apache.org> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> Jack, >>>>>>>>> >>>>>>>>> I think we should consider either allowing the storage table to be >>>>>>>>> fully exposed/addressable via the catalog or allow access via >>>>>>>>> namespacing >>>>>>>>> like with metadata tables. E.g. >>>>>>>>> <catalog>.<database>.<table>.<storage>, >>>>>>>>> which would allow for full access to the underlying table. >>>>>>>>> >>>>>>>>> For other engines to interact with the storage table (e.g. to >>>>>>>>> execute the query to materialize the table), it may be necessary that >>>>>>>>> the >>>>>>>>> table is fully addressable. Whether the storage table is returned as >>>>>>>>> part >>>>>>>>> of list operations may be something we leave up to the catalog >>>>>>>>> implementation. >>>>>>>>> >>>>>>>>> I don't think the table should reference a physical location (only >>>>>>>>> a logical reference) since things will be changing behind the view >>>>>>>>> definition and I'm not confident we want to have to update the view >>>>>>>>> representation everytime the storage table is updated. >>>>>>>>> >>>>>>>>> I think there's still some exploration as to whether we need to >>>>>>>>> model this as separate from view endpoints, but there may be enough >>>>>>>>> overlap >>>>>>>>> that it's not necessary to have yet another set of endpoints for >>>>>>>>> materialized views (maybe filter params if you need to distinguish?). >>>>>>>>> >>>>>>>>> -Dan >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> On Sun, Feb 18, 2024 at 6:57 PM Renjie Liu < >>>>>>>>> liurenjie2...@gmail.com> wrote: >>>>>>>>> >>>>>>>>>> Hi, Jack: >>>>>>>>>> >>>>>>>>>> Thanks for raising this. >>>>>>>>>> >>>>>>>>>> In most database systems, MV, view and table are considered >>>>>>>>>>> independent objects, at least at API level. It is very rare for a >>>>>>>>>>> system to >>>>>>>>>>> support operations like "materializing a logical view" or >>>>>>>>>>> "upgrading a >>>>>>>>>>> logical view to MV", because view and MV are very different in >>>>>>>>>>> almost every >>>>>>>>>>> aspect of user experience. Extending the existing view or table >>>>>>>>>>> spec to >>>>>>>>>>> accommodate MV might give us a MV implementation similar to the >>>>>>>>>>> current >>>>>>>>>>> Trino or Hive views, save us some effort and a few APIs in REST, >>>>>>>>>>> but it >>>>>>>>>>> binds us to a very specific design of MV, which we might regret in >>>>>>>>>>> the >>>>>>>>>>> future. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> When I reviewed the doc, I thought we were discussing the spec of >>>>>>>>>> materialized view, just like the spec of table metadata, but didn't >>>>>>>>>> not the >>>>>>>>>> user facing api. I would definitely agree that we should consider MV >>>>>>>>>> as >>>>>>>>>> another kind of database object in user facing api, even though it's >>>>>>>>>> internally modelled as a view + storage table pointer. >>>>>>>>>> >>>>>>>>>> If we want to make the REST experience good for MV, I think we >>>>>>>>>>> should at least consider directly describing the full metadata of >>>>>>>>>>> the >>>>>>>>>>> storage table in Iceberg view, instead of pointing to a JSON file. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Do you mean we need to add components like >>>>>>>>>> `LoadMaterializedViewResponse`, if so, I would +1 for this. >>>>>>>>>> >>>>>>>>>> *Q2: what REST APIs do we expect to use for interactions with >>>>>>>>>>> MVs?* >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> As I have mentioned above, I think we should consider MV as >>>>>>>>>> another database object, so I think we should add a set of apis >>>>>>>>>> specifically designed for MV, such as `loadMV`, `freshMV`. >>>>>>>>>> >>>>>>>>>> On Sat, Feb 17, 2024 at 11:14 AM Jack Ye <yezhao...@gmail.com> >>>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>>> Hi everyone, >>>>>>>>>>> >>>>>>>>>>> As we are discussing the spec change for materialized view, >>>>>>>>>>> there has been a missing aspect that is technically also related, >>>>>>>>>>> and might >>>>>>>>>>> affect the MV spec design: *how do we want to add MV support to >>>>>>>>>>> the REST spec?* >>>>>>>>>>> >>>>>>>>>>> I would like to discuss this in a new thread to collect people's >>>>>>>>>>> thoughts. This topic expands to the following 2 sub-questions: >>>>>>>>>>> >>>>>>>>>>> *Q1: how would the MV spec change affect the REST spec?* >>>>>>>>>>> In the current proposal, it looks like we are using a design >>>>>>>>>>> where a MV is modeled as an Iceberg view linking to an Iceberg >>>>>>>>>>> storage >>>>>>>>>>> table. At the same time, we do not want to expose this storage >>>>>>>>>>> table in the >>>>>>>>>>> catalog, thus the Iceberg view has a pointer to only a metadata >>>>>>>>>>> JSON file >>>>>>>>>>> of the Iceberg storage table. Each MV refresh updates the pointer >>>>>>>>>>> to a new >>>>>>>>>>> metadata JSON file. >>>>>>>>>>> >>>>>>>>>>> I feel this does not play very well with the direction that REST >>>>>>>>>>> is going. The REST catalog is trying to remove the dependency to the >>>>>>>>>>> metadata JSON file. For example, in LoadTableResponse the only >>>>>>>>>>> required >>>>>>>>>>> field is the metadata, and metadata-location is actually optional. >>>>>>>>>>> >>>>>>>>>>> If we want to make the REST experience good for MV, I think we >>>>>>>>>>> should at least consider directly describing the full metadata of >>>>>>>>>>> the >>>>>>>>>>> storage table in Iceberg view, instead of pointing to a JSON file. >>>>>>>>>>> >>>>>>>>>>> *Q2: what REST APIs do we expect to use for interactions with >>>>>>>>>>> MVs?* >>>>>>>>>>> So far we have been thinking about amending the view spec to >>>>>>>>>>> accommodate MV. This entails likely having MVs also being handled >>>>>>>>>>> through >>>>>>>>>>> the view APIs in REST spec. >>>>>>>>>>> >>>>>>>>>>> We need to agree with that first in the community, because this >>>>>>>>>>> has various implications, and I am not really sure at this point if >>>>>>>>>>> it is >>>>>>>>>>> the best way to go. >>>>>>>>>>> >>>>>>>>>>> If MV interactions are through the view APIs, the view APIs need >>>>>>>>>>> to be updated to accommodate MV constructs that are not really >>>>>>>>>>> related to >>>>>>>>>>> logical views. In fact, most actions performed on MVs are more >>>>>>>>>>> similar to >>>>>>>>>>> actions performed on table rather than view, which involve >>>>>>>>>>> configuring data >>>>>>>>>>> layout, read and write constructs. For example, users might run >>>>>>>>>>> something >>>>>>>>>>> like: >>>>>>>>>>> >>>>>>>>>>> CREATE MATERIALIZED VIEW mv >>>>>>>>>>> PARTITION BY col1 >>>>>>>>>>> CLUSTER BY col2 >>>>>>>>>>> AS ( // some sql ) >>>>>>>>>>> >>>>>>>>>>> then the CreateView API needs to accept partition spec and sort >>>>>>>>>>> order that are completely not relevant for logical views. >>>>>>>>>>> >>>>>>>>>>> When reading a MV, we might even want to have a >>>>>>>>>>> PlanMaterializedView API similar to the PlanTable API we are adding. >>>>>>>>>>> >>>>>>>>>>> *My personal take* >>>>>>>>>>> It feels like we need to reconsider the question of what is the >>>>>>>>>>> best way to model MV in Iceberg. Should it be (1) a view linked to a >>>>>>>>>>> storage table, or (2) a table with a view SQL associated with it, >>>>>>>>>>> or (3) >>>>>>>>>>> it's a completely independent thing. This topic was discussed in >>>>>>>>>>> the past in >>>>>>>>>>> this doc >>>>>>>>>>> <https://docs.google.com/document/d/1QAuy-meSZ6Oy37iPym8sV_n7R2yKZOHunVR-ZWhhZ6Q/edit?pli=1>, >>>>>>>>>>> but at that time we did not have much perspective about aspects >>>>>>>>>>> like REST >>>>>>>>>>> spec, and the view integration was also not fully completed yet. >>>>>>>>>>> With the >>>>>>>>>>> new knowledge, currently I am actually leaning a bit more towards >>>>>>>>>>> (3). >>>>>>>>>>> >>>>>>>>>>> In most database systems, MV, view and table are considered >>>>>>>>>>> independent objects, at least at API level. It is very rare for a >>>>>>>>>>> system to >>>>>>>>>>> support operations like "materializing a logical view" or >>>>>>>>>>> "upgrading a >>>>>>>>>>> logical view to MV", because view and MV are very different in >>>>>>>>>>> almost every >>>>>>>>>>> aspect of user experience. Extending the existing view or table >>>>>>>>>>> spec to >>>>>>>>>>> accommodate MV might give us a MV implementation similar to the >>>>>>>>>>> current >>>>>>>>>>> Trino or Hive views, save us some effort and a few APIs in REST, >>>>>>>>>>> but it >>>>>>>>>>> binds us to a very specific design of MV, which we might regret in >>>>>>>>>>> the >>>>>>>>>>> future. >>>>>>>>>>> >>>>>>>>>>> If we make a new MV spec, it can be made up of fields that >>>>>>>>>>> already exist in the table and view specs, but it is a whole new >>>>>>>>>>> spec. In >>>>>>>>>>> this way, the spec can evolve independently to accommodate MV >>>>>>>>>>> specific >>>>>>>>>>> features, and we can also create MV-related REST endpoints that >>>>>>>>>>> will evolve >>>>>>>>>>> independently from table and view REST APIs. >>>>>>>>>>> >>>>>>>>>>> But on the other side it is definitely associated with more work >>>>>>>>>>> to maintain a new spec, and potentially big refactoring in the >>>>>>>>>>> codebase to >>>>>>>>>>> make sure operations today that work on table or view can now >>>>>>>>>>> support MV as >>>>>>>>>>> a different object. And it definitely has other problems that I have >>>>>>>>>>> overlooked. I would greatly appreciate any thoughts about this! >>>>>>>>>>> >>>>>>>>>>> Best, >>>>>>>>>>> Jack Ye >>>>>>>>>>> >>>>>>>>>>>