Note: migrated from original JIRA: https://issues.apache.org/jira/browse/ARROW-6189
encoding::PlainEncoder::new creates a BitWriter with 256 bytes of storage, which limits the data page size that can be used.
I suggest that in
{{impl Encoder for PlainEncoder}}
the return value of put_value is tested and the BitWriter flushed+cleared whenever it runs out of space.