desruisseaux commented on code in PR #10981:
URL: https://github.com/apache/iceberg/pull/10981#discussion_r1806416230
##########
format/spec.md:
##########
@@ -198,6 +199,9 @@ Notes:
- Timestamp values _with time zone_ represent a point in time: values are
stored as UTC and do not retain a source time zone (`2017-11-16 17:10:34 PST`
is stored/retrieved as `2017-11-17 01:10:34 UTC` and these values are
considered identical).
- Timestamp values _without time zone_ represent a date and time of day
regardless of zone: the time value is independent of zone adjustments
(`2017-11-16 17:10:34` is always retrieved as `2017-11-16 17:10:34`).
3. Character strings must be stored as UTF-8 encoded byte arrays.
+4. Coordinate Reference System, i.e. mapping of how coordinates refer to
precise locations on earth. Defaults to "OGC:CRS84". Fixed and cannot be
changed by schema evolution.
Review Comment:
> Coordinate Reference System, i.e. mapping of how coordinates refer to
precise locations on earth. Defaults to "OGC:CRS84".
Maybe remove the word "precise"? Not all CRS are precise. The proposed
default, `OGC:CRS84`, has an uncertainty of about 2 meters (unrelated to
floating point precision). Maybe it would be worth to change the sentence to:
_Defaults to "OGC:CRS84", which provides an accuracy of about 2 meters._
Another reason for removing the "precise" word is that the CRS alone is not
sufficient for really precise locations. We also need the epoch, which is a
topic that has not been covered at all in this PR.
--
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: issues-unsubscr...@iceberg.apache.org
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscr...@iceberg.apache.org
For additional commands, e-mail: issues-h...@iceberg.apache.org
