Use "mix" shuffle spec for target size with nil clusterBy. #17810
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When a nil clusterBy is used, we have no way of achieving a particular target size, so we need to fall back to a "mix" spec (unsorted single partition). This comes up for queries like "SELECT COUNT(*) FROM FOO LIMIT 1" when results use a target size, such as when we are inserting into another table or when we are writing to durable storage.
gianm
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Area - MSQ
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extensions-core/multi-stage-query/src/test/java/org/apache/druid/msq/exec/MSQInsertTest.java
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adarshsanjeev
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Mar 19, 2025
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When a nil clusterBy is used, we have no way of achieving a particular target size, so we need to fall back to a "mix" spec (unsorted single partition).
This comes up for queries like
SELECT COUNT(*) FROM FOO LIMIT 1when results use a target size, such as when we are inserting into another table or when we are writing to durable storage.