Sahil Takiar created IMPALA-8549:
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             Summary: Add support for scanning DEFLATE text files
                 Key: IMPALA-8549
                 URL: https://issues.apache.org/jira/browse/IMPALA-8549
             Project: IMPALA
          Issue Type: Improvement
          Components: Backend
            Reporter: Sahil Takiar


Several Hadoop tools (e.g. Hive, MapReduce, etc.) support reading and writing 
text files stored using zlib / deflate (results in files such as 
{{000000_0.deflate}}). Impala currently does not support reading {{.deflate}} 
files and returns errors such as: {{ERROR: Scanner plugin 'DEFLATE' is not one 
of the enabled plugins: 'LZO'}}.

Moreover, the default compression codec in Hadoop is zlib / deflate (see 
{{o.a.h.io.compress.DefaultCodec}}). So when writing to a text table in Hive, 
if users set {{hive.exec.compress.output}} to true, then {{.deflate}} files 
will be written by default.

Impala does support zlib / deflate with other file formats though: Avro, 
RCFiles, SequenceFiles (see 
https://impala.apache.org/docs/build/html/topics/impala_file_formats.html).



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