Zoltán Borók-Nagy created IMPALA-11780:
------------------------------------------
Summary: Wrong FILE__POSITION values for multi row group Parquet
files when page filtering is used
Key: IMPALA-11780
URL: https://issues.apache.org/jira/browse/IMPALA-11780
Project: IMPALA
Issue Type: Bug
Components: Backend
Reporter: Zoltán Borók-Nagy
Impala generates wrong values for the FILE__POSITION column when the Parquet
file contains multiple row groups and page filtering is being used.
We are using the value of 'current_row_' to populate the file position slot:
https://github.com/apache/impala/blob/8dbc8b733d3712035f8615f477f74c66ec9d63ea/be/src/exec/parquet/parquet-column-readers.cc#L906
Problem is that 'current_row_' denotes the index of the row within the row
group and not withing the file. We cannot change 'current_row_' as page
filtering depends on its value, and the page index also uses the row
group-based indexes of the rows, not the file indexes.
The value of FILE__POSITION is critical for Iceberg V2 tables as position
delete files store file positions of the deleted rows.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
