[jira] [Created] (IMPALA-11414) Off-by-one error in Parquet late materialization

["Zoltán Borók-Nagy (Jira)" <ji...@apache.org>]

Zoltán Borók-Nagy created IMPALA-11414:
------------------------------------------

             Summary: Off-by-one error in Parquet late materialization
                 Key: IMPALA-11414
                 URL: https://issues.apache.org/jira/browse/IMPALA-11414
             Project: IMPALA
          Issue Type: Bug
          Components: Backend
            Reporter: Zoltán Borók-Nagy


With PARQUET_LATE_MATERIALIZATION we can set the number of minimum consecutive rows that if filtered out, we avoid materialization of rows in other columns in parquet.

E.g. if PARQUET_LATE_MATERIALIZATION is 10, and in a filtered column we find at least 10 consecutive rows that don't pass the predicates we avoid materializing the corresponding rows in the other columns.

But due to an off-by-one error we actually only need (PARQUET_LATE_MATERIALIZATION - 1) consecutive elements. This means if we set PARQUET_LATE_MATERIALIZATION to one, then we need zero consecutive filtered out elements which leads to a crash/DCHECK. The bug is in the GetMicroBatches() algorithm when we produce the micro batches based on the selected rows.

Setting PARQUET_LATE_MATERIALIZATION to 0 doesn't make sense so it shouldn't be allowed.



--
This message was sent by Atlassian Jira
(v8.20.10#820010)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-all-unsubscribe@impala.apache.org
For additional commands, e-mail: issues-all-help@impala.apache.org