[jira] [Created] (PARQUET-1364) Column Indexes: Invalid row indexes for pages starting with nulls

["Gabor Szadovszky (JIRA)" <ji...@apache.org>]

Gabor Szadovszky created PARQUET-1364:
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             Summary: Column Indexes: Invalid row indexes for pages starting with nulls
                 Key: PARQUET-1364
                 URL: https://issues.apache.org/jira/browse/PARQUET-1364
             Project: Parquet
          Issue Type: Sub-task
            Reporter: Gabor Szadovszky
            Assignee: Gabor Szadovszky


The current implementation for writing managing row indexes for the pages is not reliable. There is a logic [MessageColumnIO|https://github.com/apache/parquet-mr/blob/master/parquet-column/src/main/java/org/apache/parquet/io/MessageColumnIO.java#L153] which caches null values and flush them just *before* opening a new group. This logic might cause starting pages with these cached nulls which are not correctly counted in the written rows so the rowIndexes are incorrect. It does not cause any issues if all the pages are read continuously put it is a huge problem for column index based filtering.
The implementation described above is really complicated and would not like to redesign because of the mentioned issue. It is easier to simply count the {{0}} repetition levels as record boundaries at the column writer level.



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