Statistics for list and map
In ORC v2 (and for encrypted columns in v1), each column has
their column statistics written separately.
How was the data masked? This isn’t necessary for reading the file, but
is documentation about how the file was written.
Information about the encryption keys.
The description of an encryption variant.
Each variant is a single subtype that is encrypted with a single key.
The contents of the file tail that must be serialized.
This gets serialized as part of OrcSplit, also used by footer cache.
This message type is only used in ORC v0 and v1.
Serialized length must be less that 255 bytes
StripeStatistics (1 per a stripe), which each contain the
ColumnStatistics for each column.
This message type is only used in ORC v0 and v1.