+1 (non-binding) On Sat, Oct 31, 2026 at 10:52 AM Russell Spitzer <[email protected]> wrote:
> +1 binding > > On Sat, Oct 31, 2026 at 12:00 AM Maninder Parmar < > [email protected]> wrote: > >> +1 (non-binding) >> >> On Fri, Oct 30, 2026, 7:20 PM Junwang Zhao <[email protected]> wrote: >> >>> +1 (non-binding) >>> >>> On Sat, Oct 31, 2026 at 1:48 AM Steven Wu <[email protected]> wrote: >>> > >>> > Hi, >>> > >>> > I propose adding a _last_updated_time metadata column to row lineage >>> for v4 >>> > tables. It records the timestamp of the snapshot that last updated a >>> row, >>> > complementing _last_updated_sequence_number with a wall-clock time. >>> > >>> > Summary of the spec change: >>> > * New reserved metadata column _last_updated_time (timestamptz). >>> > * New optional tracking field snapshot_timestamp (timestamptz) in v4 >>> manifests. >>> > Writers leave it null for added entries and for entries modified by >>> > column files. On read, a null value is inherited from the snapshot's >>> > timestamp-ms. >>> > * Upgrading to v4 does not require rewriting manifest lists or >>> manifests. >>> > Pre-v4 metadata is read as if snapshot_timestamp is null, so exising >>> rows >>> > get the timestamp of the last snapshot before the v4 upgrade. >>> > >>> > This works well with the earlier v4 spec change that requires >>> monotonically >>> > increasing snapshot timestamps (#16294). Because each snapshot's >>> timestamp-ms >>> > is strictly greater than its parent's on the same branch, >>> _last_updated_time >>> > follows the same order as _last_updated_sequence_number. >>> > >>> > This enables queries for when a row was last updated and for >>> > rows modified since a given time, without mapping sequence numbers >>> > back to snapshots that may have expired. >>> > >>> > Spec PR: https://github.com/apache/iceberg/pull/18526 >>> > >>> > Please vote in the next 72 hours: >>> > >>> > [ ] +1 Adopt the spec change >>> > [ ] +0 No preference >>> > [ ] -1 Do not adopt the spec change (please explain) >>> > >>> > Thanks, Steven >>> > >>> > Discussion thread: >>> > https://lists.apache.org/thread/cln7xtjy9kw2096gzqlg5c4gg8b9td10 >>> > >>> > Monotonic snapshot timestamp PR: >>> https://github.com/apache/iceberg/pull/16294 >>> >>> >>> >>> -- >>> Regards >>> Junwang Zhao >>> >>
