andygrove · Oct 10, 2026 · Oct 10, 2026 · Oct 10, 2026
diff --git a/.ai/skills/review-comet-iceberg-write-pr/SKILL.md b/.ai/skills/review-comet-iceberg-write-pr/SKILL.md
@@ -107,8 +107,8 @@ only the latest.
       that starts trusting iceberg-rust's metrics, or adds a native-tracked value beyond float and
       double NaN counts and bounds, needs a strong reason.
 - [ ] **Value semantics match, not only formats.** iceberg-rust compares and hashes partition values
-      with its own rules: `OrderedFloat` treats `-0.0` and `0.0` as equal where Java's
-      `Float.compare` does not
+      with its own rules: until apache/iceberg-rust#3327 its `OrderedFloat` equality treated
+      `-0.0` and `0.0` as equal where Java's `Float.compare` does not
       ([#6138](https://github.com/apache/datafusion-comet/issues/6138)). Check equality, hashing,
       ordering and rendering for float, double, timestamp, timestamptz, binary and decimal.
 - [ ] **Timestamp partition values are UTC.** Iceberg's `years`, `months`, `days` and `hours`

diff --git a/docs/source/contributor-guide/iceberg-writes.md b/docs/source/contributor-guide/iceberg-writes.md
@@ -395,8 +395,9 @@ Useful places to look when checking parity:
 - `CometIcebergWriteActionSuite` writes the same data through both writers into sibling tables and
   compares rows, `readable_metrics` and partition paths.
 - iceberg-rust's own code, at the pinned revision. iceberg-rust makes different choices from
-  iceberg-java in places that matter to the table's contents, for example grouping partition keys
-  with `OrderedFloat`, which treats `-0.0` and `0.0` as equal
+  iceberg-java in places that matter to the table's contents. For example, until
+  [apache/iceberg-rust#3327](https://github.com/apache/iceberg-rust/pull/3327) it grouped
+  partition keys with `OrderedFloat`, which treats `-0.0` and `0.0` as equal
   ([#6138](https://github.com/apache/datafusion-comet/issues/6138)). Check how iceberg-rust
   compares, hashes and renders values, not only what it writes.
 

diff --git a/docs/source/user-guide/latest/iceberg-writes.md b/docs/source/user-guide/latest/iceberg-writes.md
@@ -203,7 +203,7 @@ A write is eligible only when ALL of the following hold:
 | resolved `table.locationProvider()`                                                                                                         | Iceberg's built-in `DefaultLocationProvider`                                                                                                                                                                                                                                                                                                                                                                                                                                    |
 | Hadoop S3A settings for an `s3` / `s3a` data location                                                                                       | only `fs.s3a.access.key`, `secret.key`, `session.token`, `endpoint`, `endpoint.region`, and `path.style.access`, including their `fs.s3a.bucket.<data-bucket>.*` forms; any other effective `fs.s3a.*` setting falls back                                                                                                                                                                                                                                                       |
 | Iceberg `FileIO` S3 settings for an `s3` / `s3a` data location                                                                              | the S3 endpoint, region, static/session credentials, path-style, SSE (`none`, `s3`, `kms`, or `custom`; not `dsse-kms`), assume-role, anonymous/config-chain settings parsed by the pinned iceberg-rust version, plus Comet's credential-provider class and built-in web-identity properties. When a custom provider is configured, its vendor-owned `s3.*` / `client.*` properties are also forwarded; unsupported Iceberg-defined S3 settings still fall back                 |
-| partition spec                                                                                                                              | any, except an identity partition on a `float` or `double` column, or a `void` field whose source column was dropped beside a live field (see below)                                                                                                                                                                                                                                                                                                                            |
+| partition spec                                                                                                                              | any, except a `void` field whose source column was dropped beside a live field (see below)                                                                                                                                                                                                                                                                                                                                                                                      |
 | column types                                                                                                                                | any except `uuid` (Spark plans it as a string; no Arrow cast reaches `fixed(16)`) and the v3 types `variant`, `unknown`, `timestamp_ns`, `geometry` and `geography`                                                                                                                                                                                                                                                                                                             |
 
 Within the namespaces that shape data-file bytes — `write.parquet.*` and `parquet.*` —
@@ -254,13 +254,6 @@ native write. If Iceberg's AWS property classes cannot be loaded, vendor `s3.*`
 fall back too and planning still completes. The fall-back reason reports only sorted property
 names, never their values, so credentials and tokens do not enter EXPLAIN or plan logs.
 
-An identity partition on a `float` or `double` column falls back. iceberg-rust compares float
-partition values with an equality that treats `-0.0` and `0.0` as one value, so the native writer
-would put rows with either value in the same partition, where iceberg-java writes two. A read
-that prunes on the other value's partition would then miss rows. The fall-back stays until
-iceberg-rust distinguishes the two values
-([apache/iceberg-rust#3325](https://github.com/apache/iceberg-rust/issues/3325)).
-
 On a format-version 3 table with Iceberg 1.10 or newer, a write that rewrites existing rows falls
 back. Copy-on-write `DELETE`, `UPDATE` and `MERGE` and `rewrite_data_files` write the row lineage
 columns `_row_id` and `_last_updated_sequence_number` into the new data files, so that rewritten
@@ -391,9 +384,7 @@ a data file but not what any reader computes from it:
   (iceberg-java names files `<partition>-<task>-<operation>-<count>`; iceberg-rust uses a
   process-local counter).
 - Partition directory names match iceberg-java 1.8+'s `PartitionSpec.partitionToPath` for every
-  partition type the native writer accepts. Identity partitions on `float` and `double` columns
-  fall back (see [Native Parquet write eligibility](#native-parquet-write-eligibility)), so
-  iceberg-java names those directories itself. On Iceberg 1.5.x,
+  partition type the native writer accepts. On Iceberg 1.5.x,
   which the Spark 3.4 profile pins, iceberg-java itself spelled `timestamp` and `timestamptz`
   directories with `LocalDateTime.toString()` / `OffsetDateTime.toString()`
   (`ts=1969-12-31T23:59:58.500Z`) and left the partition field name unescaped; Comet uses the

diff --git a/native/Cargo.lock b/native/Cargo.lock
diff --git a/native/Cargo.toml b/native/Cargo.toml
@@ -82,8 +82,8 @@ aws-sdk-sts = { version = "1.114.0", default-features = false }
 # Pinned to a revision rather than a release because no published iceberg-rust
 # version is on our arrow: 0.10.1 requires arrow/parquet ^58. Move to a plain
 # version requirement once a release ships on arrow 59. Bump policy: #5645.
-iceberg = { git = "https://github.com/apache/iceberg-rust", rev = "af1da4c5bc86178c38c1c6db0578bdd9fb7021e3" }
-iceberg-storage-opendal = { git = "https://github.com/apache/iceberg-rust", rev = "af1da4c5bc86178c38c1c6db0578bdd9fb7021e3", features = ["opendal-memory", "opendal-fs", "opendal-s3", "opendal-gcs", "opendal-oss", "opendal-azdls"] }
+iceberg = { git = "https://github.com/apache/iceberg-rust", rev = "1f3bc34058e3f3e45336bc5428f37b92649a608b" }
+iceberg-storage-opendal = { git = "https://github.com/apache/iceberg-rust", rev = "1f3bc34058e3f3e45336bc5428f37b92649a608b", features = ["opendal-memory", "opendal-fs", "opendal-s3", "opendal-gcs", "opendal-oss", "opendal-azdls"] }
 reqsign-core = "3"
 
 [profile.release]

diff --git a/native/core/src/execution/operators/iceberg_partition_value.rs b/native/core/src/execution/operators/iceberg_partition_value.rs
@@ -39,7 +39,7 @@ use iceberg::{Error, ErrorKind, Result};
 /// `timestamp`, or `timestamptz` source, which go through Comet's `iceberg_years` /
 /// `iceberg_months` / `iceberg_days` / `iceberg_hours` kernels instead: the ones the sort in front
 /// of a clustered write runs, pinned against iceberg-java's `DateTimeUtil` over the whole domain.
-/// iceberg-rust's transforms differ from iceberg-java's in three ways:
+/// iceberg-rust's transforms differ from iceberg-java's in two ways:
 ///
 /// - `year` and `month` split the calendar with Arrow's `date_part`, which returns NULL for
 ///   anything `chrono` cannot represent -- past year 262142 -- whereas iceberg-java goes through
@@ -49,9 +49,6 @@ use iceberg::{Error, ErrorKind, Result};
 /// - All four floor a pre-epoch timestamp that lies exactly 999999 microseconds into a unit, which
 ///   iceberg-java puts in the unit before, so `1969-01-01T00:00:00.999999` belongs in the 1968
 ///   partitions (apache/datafusion-comet#6426).
-/// - `day` moves a timestamp from the last second of a day before 1969-12-31 into the next day,
-///   unless its microsecond of second is 0 or 999999: it takes the whole seconds with a truncating
-///   division and the microseconds with a flooring one (apache/iceberg-rust#3315).
 ///
 /// A partition value that differs from the sort key can also fail a clustered write, which rejects
 /// a row whose partition it has already closed. Everywhere else the two implementations agree, so
@@ -393,7 +390,8 @@ mod tests {
             Some(-31_535_999_000_001),
             // 1969-12-31T23:00:00.999999, where that moves only the hour.
             Some(-3_599_000_001),
-            // 1969-12-30T23:59:59.5 and 1969-12-30T23:59:59.999998.
+            // 1969-12-30T23:59:59.5 and 1969-12-30T23:59:59.999998, which iceberg-rust's `day`
+            // moved into 1969-12-31 until apache/iceberg-rust#3315 was fixed.
             Some(-86_400_500_000),
             Some(-86_400_000_002),
             None,
@@ -419,7 +417,7 @@ mod tests {
             (
                 Transform::Day,
                 day([-366, -1, -2, -2]),
-                day([-365, -1, -1, -1]),
+                day([-365, -1, -2, -2]),
             ),
             (
                 Transform::Hour,
@@ -438,8 +436,7 @@ mod tests {
             for (i, (transform, java, rust)) in cases.iter().enumerate() {
                 let label = format!("{transform} of {}", source.data_type());
                 assert_eq!(&comet[i], java, "{label}");
-                // The reason Comet computes these: iceberg-rust floors the first two rows, and its
-                // `day` moves the last two into 1969-12-31 (apache/iceberg-rust#3315). If this
+                // The reason Comet computes these: iceberg-rust floors the first two rows. If this
                 // starts failing, iceberg-rust's transforms have changed and delegating needs
                 // another look.
                 assert_eq!(&iceberg_rust[i], rust, "iceberg-rust's {label}");