Adds code comments and issues a warning for Parquet files
with num_rows=0 but at least one non-empty row group.
Change-Id: I72ccf00191afddb8583ac961f1eaf11e5eb28791
Reviewed-on: http://gerrit.cloudera.org:8080/4696
Reviewed-by: Alex Behm <alex.behm@cloudera.com>
Tested-by: Internal Jenkins
For Parquet files with no row groups but with num_rows=0 in the
file footer the Parquet scanner returns an error indicating
that the file is invalid. This behavior is a regression from
previous Impala versions which used to accept such files.
This patch restores the previous behavior and adds tests.
Change-Id: I50ac3df6ff24bc5c384ef22e0f804a5132adb62e
Reviewed-on: http://gerrit.cloudera.org:8080/4693
Reviewed-by: Alex Behm <alex.behm@cloudera.com>
Tested-by: Internal Jenkins
