[HSTACK] - consolidate partitions if we have many small files

[HSTACK] - consolidate partitions if we have many small files

[bugfix] propagate the nullable flag for serialized scalar UDFS

[HSTACK] Performance hack for osx - get rid of dsymutil execution

[HSTACK] Performance hack for osx - get rid of dsymutil execution

[HSTACK] Performance hack for osx - get rid of dsymutil execution

[HSTACK] Performance hack for osx - get rid of dsymutil execution

fixup! [HSTACK] Deep column projections

fixup! [HSTACK] Deep column projections

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