Just to clarify, I was asking a question. Is it valid to add a new data file with a row?
- whose persisted row-id value is lower than the snapshot's first-row-id - whose last-updated-seq-number is not set and inherit from the snapshot sequence number Thanks, Steven On Fri, Nov 21, 2025 at 11:25 PM Péter Váry <[email protected]> wrote: > +1 for this proposal > > Slightly related, but we can move this to a separate thread if it needs > independent discussion: We should clarify the relationship between `row-id` > and `first-row-id`. This has come up several times in our discussions about > the equality delete removal proposal, where we considered generating > `row-ids` manually instead of relying on the auto-assignment feature. > > As discussed with Steven: > >> It is valid to add a new data file with a row: >> >> - whose persisted row-id value is lower than the snapshot's >> first-row-id >> - whose last-updated-seq-number is not set and inherit from the >> snapshot sequence number >> >> > Prashant Singh <[email protected]> ezt írta (időpont: 2025. nov. > 22., Szo, 5:29): > >> +1 for making it explicit that an *undelete *of a row can't be done by >> unsetting the corresponding bit in DV >> >> *Rows should only be added via new data files*, sounds reasonable to me ! >> >> apart from row-lineage it also complicates the operation type inference >> like here [1] as we would now >> inspect the contents of these DV to see if it's an insert ? >> >> [1] https://github.com/apache/iceberg/pull/14581#discussion_r2533057189 >> >> On Sat, Nov 22, 2025 at 4:48 AM Szehon Ho <[email protected]> >> wrote: >> >>> It makes sense to me, it sounds like a minor clarification. For v2 >>> position deletes, code like rewrite_position_deletes may have made some >>> assumptions like this and would not work well if violated, maybe other code >>> as well. >>> >>> Thanks >>> Szehon >>> >>> On Fri, Nov 21, 2025 at 3:03 PM Steven Wu <[email protected]> wrote: >>> >>>> Similar weird behavior can also happen for V2 position delete files >>>> with `undelete`. >>>> >>>> In V2, there could be multiple position delete files (say pd1, pd2) >>>> associated with the same data file (say f1). Let's say pd1 deletes row 5 >>>> and 10 and pd2 deletes row 15. >>>> 1. a new snapshot is committed with pd1 (DELETED), pd2 (EXISTING), and >>>> pd3 (ADDED). pd3 deletes only row 10 (undeleted row 5) >>>> 2. a new snapshot is committed with pd1 (DELETED) and pd2 (EXISTING) >>>> >>>> In either case, essentially some rows are added (back) to the table >>>> with lower sequence number than the new snapshot's sequence number. >>>> >>>> >>>> >>>> Just to recap the question: should the spec (v2 and v3) spell out that >>>> `undelete row` is not allowed? Rows should only be added via new data >>>> files. >>>> >>>> >>>> >>>> >>>> On Fri, Nov 21, 2025 at 1:09 PM Steven Wu <[email protected]> wrote: >>>> >>>>> >Are we specifically stating somewhere that all row-ids should be >>>>> higher than or equal to the snapshot's `first-row-id`? >>>>> In my mental model the `first-row-id` is only applicable for rows that >>>>> don't have a specific row-id assigned. >>>>> >>>>> I meant an ADDED row should have `row-id` higher than or equal to the >>>>> snapshot's `first-row-id`. EXISTING or UPDATED row can have lower row id. >>>>> >>>>> On Fri, Nov 21, 2025 at 1:04 PM Steven Wu <[email protected]> >>>>> wrote: >>>>> >>>>>> > Can we create a validator to prevent this from happening? >>>>>> >>>>>> We don't have this problem with the Java implementation. >>>>>> `BaseDVFileWriter` merges the previous DV with the new delta DV. So >>>>>> there >>>>>> is no `undelete` behavior. I am not aware of any Java API to allow >>>>>> "undelete". So we probably don't need to add any validation code in the >>>>>> Java impl. >>>>>> >>>>>> Just thought it is good to spell it out in the spec so that >>>>>> clients/engines can be clear about the expected behavior. >>>>>> >>>>>> On Fri, Nov 21, 2025 at 12:18 PM Péter Váry < >>>>>> [email protected]> wrote: >>>>>> >>>>>>> Are we specifically stating somewhere that all row-ids should be >>>>>>> higher than or equal to the snapshot's `first-row-id`? >>>>>>> In my mental model the `first-row-id` is only applicable for rows >>>>>>> that don't have a specific row-id assigned. >>>>>>> >>>>>>> Noneless, I agree that the `row-id` and the >>>>>>> `last-updated-seq-num` should have changed to a new one, so we can say >>>>>>> that >>>>>>> undeleting a row is not allowed because of this. >>>>>>> >>>>>>> Can we create a validator to prevent this from happening? >>>>>>> >>>>>>> >>>>>>> >>>>>>> Steven Wu <[email protected]> ezt írta (időpont: 2025. nov. 21., >>>>>>> P, 21:11): >>>>>>> >>>>>>>> The undeleted row would have invalid `row-id` and >>>>>>>> `last-updated-seq-num`. Since it is a new row (added back), it should >>>>>>>> have >>>>>>>> the `row-id` higher than or equal to the snapshot's `first-row-id` and >>>>>>>> the >>>>>>>> `last-updated-seq-number` should inherit/have the new snapshot's >>>>>>>> sequence >>>>>>>> number. >>>>>>>> >>>>>>>> On Fri, Nov 21, 2025 at 11:48 AM Steven Wu <[email protected]> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> Hi, >>>>>>>>> >>>>>>>>> Should we clarify the V3 spec to explicitly formid "*undelete*" >>>>>>>>> of a row by unsetting the DV bit? Unsetting a DV bit essentially adds >>>>>>>>> a row >>>>>>>>> with lower row-id than the snapshot's first-row-id, which would >>>>>>>>> violate the >>>>>>>>> row lineage spec. With the restriction, DV cardinality should be >>>>>>>>> monotonically increasing. >>>>>>>>> >>>>>>>>> Thanks, >>>>>>>>> Steven >>>>>>>>> >>>>>>>>
