rdblue commented on code in PR #16025: URL: https://github.com/apache/iceberg/pull/16025#discussion_r3938251210
########## format/spec.md: ########## @@ -83,9 +86,9 @@ This table format tracks individual data files in a table instead of directories Table state is maintained in metadata files. All changes to table state create a new metadata file and replace the old metadata with an atomic swap. The table metadata file tracks the table schema, partitioning config, custom properties, and snapshots of the table contents. A snapshot represents the state of a table at some time and is used to access the complete set of data files in the table. -Data files in snapshots are tracked by one or more manifest files that contain a row for each data file in the table, the file's partition data, and its metrics. The data in a snapshot is the union of all live files in its manifests; each live file may only appear once (see [Content file uniqueness](#content-file-uniqueness)). Manifest files are reused across snapshots to avoid rewriting metadata that is slow-changing. Manifests can track data files with any subset of a table and are not associated with partitions. +Data files in snapshots are tracked by one or more manifest files that contain a row for each data file in the table, the file's partition data, and its metrics. The data in a snapshot is the union of all files in its manifests. Manifest files are reused across snapshots to avoid rewriting metadata that is slow-changing. In v1-v3, data manifests and delete manifests are separate and can track files with any subset of a table; they are not associated with partitions. In v4, a data file and its deletion vector are stored in the same entry, so there is only a single manifest type, described below. Review Comment: ```suggestion Data files in snapshots are tracked by one or more manifest files that contain a row for each data file in the table, the file's partition data, an optional deletion vector (v4), and its metrics. The data in a snapshot is the union of all live rows in live data files tracked by the snapshot's manifests. Manifest files are reused across snapshots to avoid rewriting metadata that is slow-changing. ``` * I think we should add the co-located DV to the first sentence, rather than at the end * We may also want to note that the data in the table is live rows in live data files? * I would remove the v1-v3 sentence since it is complicated to explain the differences here. This only needs to be high level. We also no longer have the confusion over a manifest-per-partition so we can remove it. -- 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]
