Hi there - I'm working on a small Parquet project and encountering
some surprising results with regard to encoding decisions.

My dataset consists of ~1.5MM log lines parsed to an Avro schema and
written to a Parquet file via AvroParquetWriter. According to its log
output, Parquet is writing all int/long columns out with either
[BIT_PACKED, PLAIN] or [BIT_PACKED, PLAIN_DICTIONARY]. This surprised
me - at least one of those columns is an epoch value that should be
quite amenable to the DELTA_BINARY_PACKED. What's the best way to
understand Parquet's encoding choices?

Secondary question: Is  DELTA_BINARY_PACKED supported for INT64
columns? The documentation[1] says it is, but the code[2] suggests
otherwise.

Cheers,
--
b

[1]: 
https://github.com/apache/parquet-format/blob/master/Encodings.md#delta-encoding-delta_binary_packed--5
[2]: 
https://github.com/apache/parquet-mr/blob/master/parquet-column/src/main/java/org/apache/parquet/column/Encoding.java#L166-L168

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