RussellSpitzer commented on code in PR #18526: URL: https://github.com/apache/iceberg/pull/18526#discussion_r4364635120
########## format/spec.md: ########## @@ -483,13 +485,15 @@ A data file with only new rows for the table may omit the `_last_updated_sequenc On read, if `_last_updated_sequence_number` is `null` it is assigned the `sequence_number` of the data file's manifest entry. The data sequence number of a data file is documented in [Sequence Number Inheritance](#sequence-number-inheritance). +In v4 and later, `_last_updated_time` is set in the same way as `_last_updated_sequence_number`. On read, if `_last_updated_time` is `null` it is assigned the `snapshot_timestamp` of the data file's tracking metadata, documented in [Commit Timestamp Inheritance](#commit-timestamp-inheritance). + When `null`, a row's `_row_id` field is assigned to the `first_row_id` from its containing data file plus the row position in that data file (`_pos`). A data file's `first_row_id` field is assigned using inheritance and is documented in [First Row ID Inheritance](#first-row-id-inheritance). A manifest's `first_row_id` is assigned when writing the snapshot root file and is documented in [Snapshot Root File First Row ID Assignment](#snapshot-root-file-first-row-id-assignment). Starting in v4, a data file in the root manifest is assigned a `first_row_id` in the same way. A snapshot's `first-row-id` is set to the table's `next-row-id` and is documented in [Snapshot Row IDs](#snapshot-row-ids). -When an existing row is moved to a different data file for any reason, writers should write `_row_id` and `_last_updated_sequence_number` according to the following rules: +When an existing row is moved to a different data file for any reason, writers should write `_row_id`, `_last_updated_sequence_number`, and in v4 and later `_last_updated_time` according to the following rules: 1. The row's existing non-null `_row_id` must be copied into the new data file -2. If the write has modified the row, the `_last_updated_sequence_number` field must be set to `null` (so that the modification's sequence number replaces the current value) -3. If the write has not modified the row, the existing non-null `_last_updated_sequence_number` value must be copied to the new data file +2. If the write has modified the row, the `_last_updated_sequence_number` field and, in v4 and later, the `_last_updated_time` field must be set to `null` (so that the modification's sequence number and commit timestamp replace the current values) Review Comment: commit -> snapshot -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
