nastra commented on code in PR #8982:
URL: https://github.com/apache/iceberg/pull/8982#discussion_r1382914816
##########
format/spec.md:
##########
@@ -1370,3 +1370,16 @@ Writing v2 metadata:
* `sort_columns` was removed
Note that these requirements apply when writing data to a v2 table. Tables
that are upgraded from v1 may contain metadata that does not follow these
requirements. Implementations should remain backward-compatible with v1
metadata requirements.
+
+## Appendix F: Implementation Notes
+
+This section covers topics not required by the specification but
recommendations for systems implementing the Iceberg specification
+to help maintain a uniform experience.
+
+### Point in Time Reads (Time Travel)
+
+Iceberg supports two types of histories for tables. A history of previous
"current snapshots" stored ["snapshot-log" table
metadata](#table-metadata-fields) and [parent-child lineage stored in
"snapshots"](#table-metadata-fields). These two histories
+might not be consistent for determining a table states at a given point in
time due to a variety of table operations (e.g. branch-merge table workflows OR
forcing the current state of table to specific snapshot ID).
+
+When processing point in time queries the Iceberg community has chosen to use
"snapshot-log" metadata lookup the table state
Review Comment:
```suggestion
When processing point in time queries the Iceberg community has chosen to
use "snapshot-log" metadata to lookup the table state
```
--
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]
