[I] The example in delta-encoding seems incorrect [parquet-format]

["asfimport (via GitHub)" <gi...@apache.org>]

asfimport opened a new issue, #393:
URL: https://github.com/apache/parquet-format/issues/393

   In the example using delta-encoded, encoding [1, 2, 3, 4, 5], we state that
   
   ```java
   
   The final encoded data is:
   
   header: 8 (block size), 1 (miniblock count), 5 (value count), 1 (first value)
   
   block 1 (minimum delta), 0 (bitwidth), (no data needed for bitwidth 0)
   ```
   
   I believe that the correct result should be
   
   header: [8, 1, 5, 2]
   block: [2, 0]
   
   I.e first_value and min_delta should be 2, not 1.
   
   This is because the zig-zag ULEB128-encoding of 1 is 2: the ULEB-128 encoding of 1 is 1, but AFAIK the zig-zag encoding of 1 is 2 (see e.g. [here](https://stackoverflow.com/a/2211086/931303)).
   
   Alternatively, we could re-phrase "The final encoded data is:" to "The final data prior to zig-zag encoding is:"
   
   
   
   
   
   **Reporter**: [Jorge Leitão](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=jorgecarleitao) / @jorgecarleitao
   
   <sub>**Note**: *This issue was originally created as [PARQUET-2028](https://issues.apache.org/jira/browse/PARQUET-2028). Please see the [migration documentation](https://issues.apache.org/jira/browse/PARQUET-2502) for further details.*</sub>


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