wmoustafa commented on a change in pull request #4301:
URL: https://github.com/apache/iceberg/pull/4301#discussion_r823199510
##########
File path: format/spec.md
##########
@@ -193,10 +193,38 @@ Notes:
For details on how to serialize a schema to JSON, see Appendix C.
+#### Default value
+Default values can be assigned to top-level columns or nested fields. Default
values are used during schema evolution when adding a new column. The default
value is used to read rows belonging to the files that lack the column or
nested field prior to the schema evolution.
Review comment:
> * New writes to the table do not use Default Values
> a. Required Columns are still required at write time
> b. Optional Columns are still persisted as null if they are missing at
write time
I would skip "New" here. I think default values are not used on the write
path at all.
--
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]
