> As a side note, the `rest-catalog-open-api.yaml` file [2] in the Iceberg repo 
> contains the latest version of the spec.

I think more clarity on this would be helpful. Is it really the case that the 
Open API spec contains the latest version of the spec? For example, I'm 
noticing a discrepancy between sequence-number in the Table Spec and in the 
Open API Spec...

In the table spec, it's required for V2, but it's optional in the REST API Spec:
https://github.com/apache/iceberg/blob/main/open-api/rest-catalog-open-api.yaml#L2319-L2335

On 2024/10/17 16:58:17 Kevin Liu wrote:
> > Based on the example metadata, that looks like it is not to spec, so it's
> reasonable that python would reject it.  If the java implementation is
> allowing for that, it's likely that we're being too relaxed (possibly a
> holdover from v1 parsing).
> I believe the Java implementation is relaxing the constraint. I'll create a
> PR with test cases and the necessary changes.
> 
> > Do you know what produced the metadata?
> It was created by Snowflake [1]. After verifying this, I'll look into
> raising the issue with them.
> 
> As a side note, the `rest-catalog-open-api.yaml` file [2] in the Iceberg
> repo contains the latest version of the spec. As we're continuing to evolve
> to spec for V3, would it be helpful to create a frozen version representing
> both the V1 and V2 specs for reference, possibly as a separate file?
> 
> Best,
> Kevin Liu
> 
> [1]
> https://github.com/apache/iceberg-python/issues/1106#issuecomment-2312108455
> [2]
> https://github.com/apache/iceberg/blob/8e2eb9ac2e33ce4bac8956d4e2f099444d03c0e3/open-api/rest-catalog-open-api.yaml
> 
> On Thu, Oct 17, 2024 at 9:20 AM Daniel Weeks <dwe...@apache.org> wrote:
> 
> > Sung,
> >
> > I was thinking of v1, so you're right that manifest-list and summary are
> > required as of v2.  The REST Spec seems to follow the v2 definition, so I
> > think we're somewhat implicitly requiring those fields via REST.
> >
> > Kevin,
> >
> > Based on the example metadata, that looks like it is not to spec, so it's
> > reasonable that python would reject it.  If the java implementation is
> > allowing for that, it's likely that we're being too relaxed (possibly a
> > holdover from v1 parsing).
> >
> > Do you know what produced the metadata?
> >
> > -Dan
> >
> > On Thu, Oct 17, 2024 at 9:02 AM Kevin Liu <kevin.jq....@gmail.com> wrote:
> >
> >> Thanks for the additional context.
> >>
> >> My understanding is that if a Snapshot has a `summary` field, it must
> >> also have a corresponding `operation` key in the summary map. Is that
> >> correct? Based on the `SnapshotParser`, this is not enforced [1].
> >>
> >> The underlying issue in #1106 [2] is the missing `operation` field when
> >> the `summary` field is present.
> >> For example,
> >> ```
> >>     "summary" : {
> >>       "manifests-created" : "8",
> >>       "total-records" : "26508666891",
> >>       "added-files-size" : "3927895626752",
> >>       "manifests-kept" : "0",
> >>       "total-files-size" : "3927895626752",
> >>       "added-records" : "26508666891",
> >>       "added-data-files" : "231513",
> >>       "manifests-replaced" : "0",
> >>       "total-data-files" : "231513"
> >>     }
> >> ```
> >>
> >> It could be the case that this particular `metadata.json` was generated
> >> not according to the spec.
> >>
> >> Best,
> >> Kevin Liu
> >>
> >>
> >> [1]
> >> https://github.com/apache/iceberg/blob/17f1c4d2205b59c2bd877d4d31bbbef9e90979c5/core/src/main/java/org/apache/iceberg/SnapshotParser.java#L124-L142
> >> [2] https://github.com/apache/iceberg-python/issues/1106
> >>
> >>
> >> On Thu, Oct 17, 2024 at 8:47 AM Sung Yun <sun...@apache.org> wrote:
> >>
> >>> Thank you for the clarification Daniel, and thank you Kevin for raising
> >>> this issue!
> >>>
> >>> Does that mean that we are creating component schemas that are the
> >>> superset of the V1 and V2 schemas? And if so, should we remove summary and
> >>> manifest-list from the required properties, and add manifests optional
> >>> property to the Snapshot schema to support both V1 and V2 Summary specs?
> >>> https://iceberg.apache.org/spec/#snapshots
> >>>
> >>> Or would creating separate component schemas for V1/V2 be a cleaner way
> >>> to align the REST spec with the table spec?
> >>>
> >>> Sung
> >>>
> >>> On 2024/10/17 15:19:23 Daniel Weeks wrote:
> >>> > I'm not convinced this is incorrect behavior (table spec or
> >>> > implementation), but it does lend to some confusion.  The 'summary'
> >>> field
> >>> > is optional, which means that if a summary is not provided, you do not
> >>> have
> >>> > an associated 'operation' field.  The 'operation' field is only
> >>> required in
> >>> > the context of the summary, so it's actually possible for the
> >>> > implementation (i.e. the tests you reference) to not have an operation.
> >>> >
> >>> > I think what is wrong here is that the REST spec marked the summary as
> >>> > required
> >>> > <
> >>> https://github.com/apache/iceberg/blob/8e2eb9ac2e33ce4bac8956d4e2f099444d03c0e3/open-api/rest-catalog-open-api.yaml#L2040
> >>> >,
> >>> > which is inconsistent with the table spec.
> >>> >
> >>> > On Wed, Oct 16, 2024 at 3:52 PM Anton Okolnychyi <
> >>> aokolnyc...@gmail.com>
> >>> > wrote:
> >>> >
> >>> > > Based on [1], we never persisted the operation in the summary map.
> >>> > > Instead, we persisted it as a top-level field in Java, which is
> >>> actually
> >>> > > NOT what the spec says. Does anyone remember cases when the
> >>> operation was
> >>> > > unknown? I personally don't.
> >>> > >
> >>> > > [1] -
> >>> > >
> >>> https://github.com/apache/iceberg/blob/17f1c4d2205b59c2bd877d4d31bbbef9e90979c5/core/src/main/java/org/apache/iceberg/SnapshotParser.java#L63
> >>> > >
> >>> > >
> >>> > > ср, 16 жовт. 2024 р. о 12:42 Kevin Liu <kevin.jq....@gmail.com>
> >>> пише:
> >>> > >
> >>> > >> Hey folks,
> >>> > >>
> >>> > >> I’ve noticed a discrepancy between the Iceberg specification and
> >>> the Java
> >>> > >> implementation regarding the `operation` key in the `Snapshot`
> >>> `summary`
> >>> > >> field.
> >>> > >>
> >>> > >> The `Snapshot` object's `summary` dictionary includes a *required*
> >>> key
> >>> > >> named `operation`, as outlined in the spec describing Table
> >>> Metadata and
> >>> > >> Snapshots [1] and the generated OpenAPI YAML [2]. However, in the
> >>> Java
> >>> > >> implementation [3], `operation` is treated as optional. In
> >>> contrast, it
> >>> > >> remains a required field in the Python implementation [4].
> >>> > >> I also found that Java tests for `SnapshotParser` assert that the
> >>> > >> `operation` field is null. [5]
> >>> > >>
> >>> > >> Due to this discrepancy, a user reported [6] that the
> >>> `metadata.json`
> >>> > >> file generated for an Iceberg table could not be read by PyIceberg,
> >>> though
> >>> > >> it is readable using the Iceberg Java library.
> >>> > >>
> >>> > >> How should we proceed from here? Should the Java library enforce
> >>> this
> >>> > >> requirement? Additionally, how should we handle existing
> >>> `metadata.json`
> >>> > >> files that were generated without this field?
> >>> > >>
> >>> > >> Best,
> >>> > >> Kevin Liu
> >>> > >>
> >>> > >> [1] https://iceberg.apache.org/spec/#table-metadata-and-snapshots
> >>> > >> [2]
> >>> > >>
> >>> https://github.com/apache/iceberg/blob/8e2eb9ac2e33ce4bac8956d4e2f099444d03c0e3/open-api/rest-catalog-open-api.yaml#L2057-L2060
> >>> > >> [3]
> >>> > >>
> >>> https://github.com/apache/iceberg/blob/64b36999d7ff716ae2534fb0972fcc10d22a64c2/core/src/main/java/org/apache/iceberg/SnapshotParser.java#L124
> >>> > >> [4]
> >>> > >>
> >>> https://github.com/apache/iceberg-python/blob/7cf0c225c3cdb32ac5e390de06b7b0e4fe7de92e/pyiceberg/table/snapshots.py#L182
> >>> > >> [5]
> >>> > >>
> >>> https://github.com/apache/iceberg/blob/22a6b19c2e226eacc0aa78c1f2ffbdbb168b13be/core/src/test/java/org/apache/iceberg/TestSnapshotJson.java#L52
> >>> > >> [6] https://github.com/apache/iceberg-python/issues/1106
> >>> > >>
> >>> > >>
> >>> >
> >>>
> >>
> 

Reply via email to