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Fix reading Iceberg $manifests table when contains_nan is NULL #11241

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Merged
findepi merged 1 commit into from
Mar 25, 2022
Merged

Fix reading Iceberg $manifests table when contains_nan is NULL #11241

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8 changes: 7 additions & 1 deletion plugin/trino-iceberg/src/main/java/io/trino/plugin/iceberg/ManifestsTable.java
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Original file line number Diff line number Diff line change
Expand Up @@ -137,7 +137,13 @@ private static void writePartitionSummaries(BlockBuilder arrayBlockBuilder, List

BlockBuilder rowBuilder = singleArrayWriter.beginBlockEntry();
BOOLEAN.writeBoolean(rowBuilder, summary.containsNull());
BOOLEAN.writeBoolean(rowBuilder, summary.containsNaN());
Boolean containsNan = summary.containsNaN();
if (containsNan == null) {
rowBuilder.appendNull();
}
else {
BOOLEAN.writeBoolean(rowBuilder, containsNan);
}
Comment on lines 140 to 146
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@hashhar hashhar Mar 1, 2022

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Optional may be handy here

            Optional.ofNullable(summary.containsNaN()).ifPresentOrElse(
                    containsNan -> BOOLEAN.writeBoolean(rowBuilder, containsNan),
                    rowBuilder::appendNull);

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@findinpath findinpath Mar 1, 2022

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I was thinking now also about something similar. A similar change would be beneficial for unboxing other types as well.

Alternatively this could be handled behind the scenes within BOOLEAN if we pass Boolean instead of boolean

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@hashhar hashhar Mar 1, 2022

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I'd love to avoid nullable reference types where possible. Quite easy to miss.

The writer being "smarter" means it's easy to introduce mistakes.

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@kbendick kbendick Mar 3, 2022

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Hi all

The field is nullable per the spec. It's generally only missing for older data files, so it's usually encountered (and why it's not super reproducible). But it is nullable per the spec. Older tables won't have this field populated and so that is a source of issue.

It is easy to encounter NPEs in my opinion so I typically prefer to handle things with optionals, but it is usually present (if that informs your thinking at all for performance etc) 👍

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@kbendick kbendick Mar 3, 2022

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For reference, here is the equivalent code for the scan in Spark: https://github.com/apache/iceberg/blob/68091037944ff7e9de91e7b619f313a8e98c1adc/core/src/main/java/org/apache/iceberg/ManifestsTable.java#L102-L123

Note that the column is nullable: https://github.com/apache/iceberg/blob/68091037944ff7e9de91e7b619f313a8e98c1adc/core/src/main/java/org/apache/iceberg/ManifestsTable.java#L41

VARCHAR.writeString(rowBuilder, field.transform().toHumanString(
Conversions.fromByteBuffer(nestedType, summary.lowerBound())));
VARCHAR.writeString(rowBuilder, field.transform().toHumanString(
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