anuragmantri commented on code in PR #16425: URL: https://github.com/apache/iceberg/pull/16425#discussion_r4386267387
########## format/spec.md: ########## Review Comment: Update: the rule now lives in Writing Column Files and covers v2 position delete files and deletion vectors in delete manifests too. The sentence in Equality Delete Files is a pointer. ########## format/spec.md: ########## @@ -1653,6 +1656,61 @@ If a delete column in an equality delete file is later dropped from the table, i Manifests hold the same statistics for delete files and data files. For delete files, the metrics describe the values that were deleted. +### Column Updates + +Starting in v4, the values of one or more fields in a data file can be updated without rewriting the data file by adding column files using the [`column_files`](#column-file-fields) field. This section describes column files for data files. + +In this section, the **previous entry** is the live entry of the data file before a column update, the **MODIFIED entry** is the entry produced by the column update, an **updated field** is a field whose ID is in the `field_ids` of a column file added by the column update, and an **updated row** is a row modified by the column update. + +#### Column Files + +A column file is a valid Iceberg data file: files must use valid Iceberg formats, schemas, and column projection. + +A column file stores the entire value of each field whose ID is in its `field_ids`. Each ID in `field_ids` must be the ID of a top-level field in the table schema used to write the column file, or the ID of a row lineage field required by [Adding Column Files](#adding-column-files). Review Comment: Note: "Adding Column Files" is now "Writing Column Files" and comes before "Reading Column Files", per Steven's comments. -- 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]
