read_parquet() type mapping changes:
STRING logical type and the UTF8
converted type are still read as a character vector, but
BYTE_ARRAY types without a converted or logical types are
not any more, and are read as a list of raw vectors. Missing values are
indicated as NULL values.DECIMAL converted type is read as a
REALSXP now, even if its type is
FIXED_LEN_BYTE_ARRAY. (Not just if it is
BYTE_ARRAY).UUID logical type is now read as a character
vector, formatted as
00112233-4455-6677-8899-aabbccddeeff.BYTE_ARRAY and FIXED_LEN_BYTE_ARRAY types
without logical or converted types; or with unsupported ones:
FLOAT16, INTERVAL; are now read into a list of
raw vectors. Missing values are denoted by NULL.write_parquet() now automatically uses dictionary
encoding for columns that have many repeated values. Only the first 10k
rows are used to decide if dictionary will be used or not. Similarly,
logical columns are written in RLE encoding if they contain runs of
repeated values. NA values are ignored when selecting the
encoding (#18).
write_parquet() can now write a data frame to a
memory buffer, returned as a raw vector, if the special
":raw:" filename is used (#31).
read_parquet() can now read Parquet files with V2
data pages (#37).
Both read_parquet() and write_parquet()
now support GZIP and ZSTD compressed Parquet files.
read_parquet() now supports the RLE
encoding for BOOLEAN columns and also supports the
DELTA_BINARY_PACKED, DELTA_LENGTH_BYTE_ARRAY,
DELTA_BYTE_ARRAY and BYTE_STREAM_SPLIT
encodings.
The parquet_columns() function is now called
parquet_column_types() and it can now map the column types
of a data frame to Parquet types.
parquet_info(), parquet_metadata() and
parquet_column_types() now work if the
created_by metadata field is unset.
New parquet_options() function that you can use to
set nanoparquet options for a single read_parquet() or
write_parquet() call.