dramaticlly commented on PR #12172:
URL: https://github.com/apache/iceberg/pull/12172#issuecomment-2641532788

   I did some look on this, I think right now the only strict delta 
manifest-list/manifests/data files are rewritten if `start_version` is 
provided. So for incremental rewrite and copy does not result in cumulative of 
all deltas on read. Collected some details  from provided unit test examples to 
help visualize the problem
   
   1st snapshot: 4355148708777346214
   2nd snapshot: 936971667881185972
   
   - source table
   ```
   
+--------------------------------------------------------------------------------+-----------------------------------------------------------+-------------------+
   |manifest-list                                                               
    |path                                                       
|added_snapshot_id  |
   
+--------------------------------------------------------------------------------+-----------------------------------------------------------+-------------------+
   
|1224/metadata/snap-936971667881185972-1-7a1b9514-44b9-418e-a6b3-dd724a5daa01.avro|1224/metadata/7a1b9514-44b9-418e-a6b3-dd724a5daa01-m0.avro|936971667881185972
 |
   
|1224/metadata/snap-936971667881185972-1-7a1b9514-44b9-418e-a6b3-dd724a5daa01.avro|1224/metadata/a3362153-e2aa-4e7c-a04e-7ea9f525d0ce-m0.avro|4355148708777346214|
   
+--------------------------------------------------------------------------------+-----------------------------------------------------------+-------------------+
   
   
+----------------------------------------------------------+------+-------------------+-----------------------------------------------------------------------+
   |manifest-file                                             
|status|snapshot_id       |file_path                                            
                   |
   
+----------------------------------------------------------+------+-------------------+-----------------------------------------------------------------------+
   |1224/metadata/7a1b9514-44b9-418e-a6b3-dd724a5daa01-m0.avro|1     
|936971667881185972 
|1224/data/00000-16-2c43c06a-e56e-4c74-a498-393398ac66df-0-00001.parquet|
   |1224/metadata/a3362153-e2aa-4e7c-a04e-7ea9f525d0ce-m0.avro|1     
|4355148708777346214|1224/data/00000-2-f37fff9f-1075-4e06-85e1-fa7c3f22ac48-0-00001.parquet
 |
   
+----------------------------------------------------------+------+-------------------+-----------------------------------------------------------------------+
   ```
   
   - target table
   ```
   
+--------------------------------------------------------------------------------+-----------------------------------------------------------+------------------+
   |manifest-list                                                               
    |path                                                       
|added_snapshot_id |
   
+--------------------------------------------------------------------------------+-----------------------------------------------------------+------------------+
   
|4614/metadata/snap-936971667881185972-1-7a1b9514-44b9-418e-a6b3-dd724a5daa01.avro|4614/metadata/7a1b9514-44b9-418e-a6b3-dd724a5daa01-m0.avro|936971667881185972|
   
+--------------------------------------------------------------------------------+-----------------------------------------------------------+------------------+
   
   
+----------------------------------------------------------+------+-------------------+-----------------------------------------------------------------------+
   |manifest-file                                             
|status|snapshot_id       |file_path                                            
                   |
   
+----------------------------------------------------------+------+-------------------+-----------------------------------------------------------------------+
   |4614/metadata/7a1b9514-44b9-418e-a6b3-dd724a5daa01-m0.avro|1     
|936971667881185972|4614/data/00000-16-2c43c06a-e56e-4c74-a498-393398ac66df-0-00001.parquet
 |
   
+----------------------------------------------------------+------+-------------------+-----------------------------------------------------------------------+
   ```
   
   So incremental copy after 1st snapshot, read of target table ends up with 
only the delta for all iceberg metadata related to snapshot 
`936971667881185972` 


-- 
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

Reply via email to