hi Colin, Phillip Cloud is the expert on this topic, but I believe we only support writing decimals to FIXED_LEN_BYTE_ARRAY physical type in Parquet right now
https://github.com/apache/parquet-cpp/blob/master/src/parquet/arrow/writer.cc#L798 The size of the type depends on the decimal precision, so if we can write to 32- or 64-bit, then we do that. Writing to INT32 or INT64 would be more complicated and require some work in parquet-cpp - Wes On Wed, Apr 18, 2018 at 7:04 PM, Colin Nichols <co...@narrativ.com> wrote: > Hi all, > > Any thoughts on the below? I did a little more code browsing and I'm not > sure this is supported right now, should I open a Jira ticket? > > - Colin > > On Tue, Apr 17, 2018 at 11:11 PM, Colin Nichols <co...@narrativ.com> wrote: > >> Hi there, >> >> I know (py)arrow has the decimal128() type, and using this type it's easy >> to take an array of Python Decimals, convert to a pa.array, and write out >> to Parquet. >> >> In the absence (afaict) of decimal32 and decimal64 types, is it possible >> to go from an array of Decimals (with compatible precision/scale) and write >> them to a parquet column of 32- or 64- bit width? >> >> Relevant parquet spec -- https://github.com/apache/ >> parquet-format/blob/master/LogicalTypes.md#decimal >> >> I'm looking to add this functionality to the project Spectrify, as AWS >> Redshift Spectrum will not query unnecessarily-wide DECIMAL columns -- >> https://github.com/hellonarrativ/spectrify/issues/14 >> >> Thanks, >> Colin >> >>
