rdblue commented on code in PR #18526: URL: https://github.com/apache/iceberg/pull/18526#discussion_r4461858630
########## format/spec.md: ########## @@ -1237,6 +1243,20 @@ Inheriting sequence numbers through the metadata tree allows writing a new manif Inheritance does not apply to v1, which does not have inherited fields like sequence number. When reading v1 manifests with no sequence number column, sequence numbers for all files must default to 0. +##### Snapshot Timestamp Inheritance + +In v4 and later, the `snapshot_timestamp` tracking field records the `timestamp-ms` of the snapshot that added or last modified a file's data, converted to microseconds. It is used to assign `_last_updated_time` for [row lineage](#row-lineage). + +Writers must set `tracking.snapshot_timestamp` for data file and leaf manifest entries as follows: + +* An ADDED entry must have a `null` `snapshot_timestamp`. +* An entry MODIFIED by column files must have a `null` `snapshot_timestamp`. Review Comment: Combine with the first row since this is a single statement. -- 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]
