Re: [I] write_table does not respect indices dtype [arrow]

["idavi-bcs (via GitHub)" <gi...@apache.org>]

idavi-bcs commented on issue #36589:
URL: https://github.com/apache/arrow/issues/36589#issuecomment-1781310090

   Unfortunately it looks like this is a well-known bug at this point, reported multiple times (#36589, #30302, #27616).  However, I want to point out an important impact that I haven't seen mentioned yet.  I have a large data table of int8 categoricals (genotype data), but it still fits comfortably in memory, and can easily be written to Parquet.  But I cannot *read* the Parquet file back into memory, because now it takes 5 times as much space (int32 + int8 in memory simultaneously as Pandas tries to cast back to int8).  So my data is effectively lost.
   
   In other words, this is not just a performance bug -- it can actually cause data loss in the case of large tables!


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