Hi Manu,
No rewrite of the existing manifests is needed. The V4 root manifest references the existing V2/V3 manifests as-is (data manifests and the older delete manifests), so upgrade stays metadata-only regardless of table size; only the new top-level V4 metadata is written. The equality deletes in those carried-over delete manifests are still applied on read (with 2-phase planning) until they age off or are converted to DVs by a separate maintenance action. Thanks, Huaxin On Thu, Aug 13, 2026 at 10:18 AM Manu Zhang <[email protected]> wrote: > Hi Huaxin, > > To clarify the third point: will upgrading a V2/V3 table to a V4 table > require a manifest rewrite? If so, how will that process be handled? > > Thanks, > Manu > > > On Thu, Aug 13, 2026 at 10:07 AM huaxin gao <[email protected]> > wrote: > >> Hi all, >> >> Following the discussion thread "[DISCUSS] Deprecate Equality Deletes in >> Iceberg V4" [1], I'd like to call a vote on the following proposal for the >> V4 table spec. >> >> Proposal >> -------- >> 1. Writing new equality deletes is forbidden for V4 tables: the V4 >> metadata >> will not define equality deletes as an allowed entry type. >> >> 2. Reading equality deletes remains supported in the reference >> implementation for backward compatibility, both for existing V2/V3 >> tables and for equality deletes carried over into upgraded V4 tables. >> >> 3. Upgrading a V2/V3 table to V4 is metadata-only (no synchronous rewrite >> of data or delete files). Existing equality deletes remain in carried- >> over V2/V3 delete manifests; converting them to deletion vectors is a >> separate, optional maintenance action. >> >> Rationale >> --------- >> Equality deletes impose an asymmetric cost paid on every read, complicate >> the format, and block features such as CDC, row lineage, and incremental >> index/materialized-view maintenance. Deletion vectors make deletion a >> flat, >> one-time cost, and the Flink ConvertEqualityDeletes work demonstrates a >> viable replacement path, so we do not need the full replacement completed >> before forbidding new equality deletes in V4. >> >> The vote will be open for at least 72 hours. >> >> [ ] +1 Forbid writing equality deletes in V4 >> [ ] +0 >> [ ] -1 Do not forbid (please explain) >> >> [1] https://lists.apache.org/thread/ks01jpv40qjlvz4yop5tlqv4x5oxbwy6 >> >> Thanks, >> Huaxin >> >
