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https://issues.apache.org/jira/browse/IMPALA-14123?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Csaba Ringhofer resolved IMPALA-14123.
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Fix Version/s: Impala 5.0.0
Resolution: Fixed
> Allow Iceberg predicate push down on non-partition columns
> ----------------------------------------------------------
>
> Key: IMPALA-14123
> URL: https://issues.apache.org/jira/browse/IMPALA-14123
> Project: IMPALA
> Issue Type: Improvement
> Components: Frontend
> Reporter: Csaba Ringhofer
> Assignee: Csaba Ringhofer
> Priority: Major
> Labels: iceberg, impala-iceberg, performance
> Fix For: Impala 5.0.0
>
>
> Since IMPALA-11591 Impala only calls Iceberg's planFiles() when at least one
> predicate can be pushed down for a partition column.
> https://github.com/apache/impala/blob/006f9ba589cc7d104bc81927ebba647cafc0d39b/fe/src/main/java/org/apache/impala/planner/IcebergScanPlanner.java#L828
> This is a useful optimization in general because if Iceberg can't skip many
> files based on stats then calling planFiles() makes planning slower without
> benefit. There are some cases though when many files could be skipped during
> planning and doing this would make the query much faster. In most cases
> Impala would still not read the whole data file, as Parquet min/max filtering
> would drop row groups based on the footer, but knowing this during planning
> would lead to a more efficient plan.
> Some cases where planning time stat filtering could be useful:
> 1. sorting columns
> 2. column with some hidden relation to sorting or partition columns
> 3. cases when Impala's scanner can't do file level stat filtering - the
> obvious examples are Avro files, but Parquet/ORC min/max filtering also has
> limitations
> some examples for 2 ("hidden partitioning/clustering"):
> a. table is partitioned by country of a point, filter is on x/y coordinates
> b. table is sorted by send_date, but filtered by receive_date - the two are
> likely to correlate
>
> My idea is to provide a way to configure how Impala behaves (with the
> exception of explicit sorting columns, where this info is available):
> 1. create a query option that enables calling planFiles() in all cases - this
> is also useful to make Impala more consistent with other engines, for example
> when benchmarking running Impala with both values can give useful insights
> 2. add a table property that lists the columns where predicates should be
> pushed down to Iceberg - this could be also computed automatically by a tool
> that checks overlaps among file min/max ranges
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