Amogh Margoor has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/17765 )

Change subject: IMPALA-10840: Add support for "FOR SYSTEM_TIME AS OF" and "FOR 
SYSTEM_VERSION AS OF" for Iceberg tables
......................................................................


Patch Set 5:

(4 comments)

http://gerrit.cloudera.org:8080/#/c/17765/5/fe/src/main/cup/sql-parser.cup
File fe/src/main/cup/sql-parser.cup:

http://gerrit.cloudera.org:8080/#/c/17765/5/fe/src/main/cup/sql-parser.cup@3066
PS5, Line 3066: opt_asof ::=
This is cool. Btw Delta also supports '@' syntax which can be convenient and 
less verbose sometimes:

SELECT * FROM events@20190101000000000 (timestamp)
SELECT * FROM events@v123 (version)


We can consider it in future based on adoption.


http://gerrit.cloudera.org:8080/#/c/17765/5/tests/query_test/test_iceberg.py
File tests/query_test/test_iceberg.py:

http://gerrit.cloudera.org:8080/#/c/17765/5/tests/query_test/test_iceberg.py@116
PS5, Line 116:   def test_time_travel(self, vector, unique_database):
One generic question about Time Travel I had was w.r.t Compaction:
I guess Iceberg supports compaction of data files using rewriteDataFiles 
through some engines. Suppose we compact data files between time stamp T1, T2, 
T3, ... T10 and after compaction we query via this feature for timestamp T3. 
Will Iceberg library 'scan.asOfTime' fail for that ?


http://gerrit.cloudera.org:8080/#/c/17765/5/tests/query_test/test_iceberg.py@171
PS5, Line 171:     # Future queries return the current snapshot.
nice. Is it similar behaviour when we specify version greater than the current 
version ?


http://gerrit.cloudera.org:8080/#/c/17765/5/tests/query_test/test_iceberg.py@205
PS5, Line 205:       self.execute_query("SELECT * FROM {0} FOR SYSTEM_TIME AS 
OF {1}".format(
Does this cover the case when older snapshots are expired too
?
table.expireSnapshots()
     .expireOlderThan(tsToExpire)
     .commit();



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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: Ib523c5e47b8d9c377bea39a82fe20249177cf824
Gerrit-Change-Number: 17765
Gerrit-PatchSet: 5
Gerrit-Owner: Zoltan Borok-Nagy <[email protected]>
Gerrit-Reviewer: Amogh Margoor <[email protected]>
Gerrit-Reviewer: Attila Jeges <[email protected]>
Gerrit-Reviewer: Impala Public Jenkins <[email protected]>
Gerrit-Reviewer: Qifan Chen <[email protected]>
Gerrit-Reviewer: Zoltan Borok-Nagy <[email protected]>
Gerrit-Comment-Date: Fri, 27 Aug 2021 11:06:13 +0000
Gerrit-HasComments: Yes

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