Monday, 27 January 2014

Inserted Sorts

Inserted Sorts

By default, tsort operators are inserted into the score as necessary
– Before any stage that requires matched key values (Join, Merge, RemDups)

Only inserted if the user has NOT explicitly defined a sort

Check the job score for inserted tsort operators

Changing Inserted Sorting Behavior

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 Set $APT_SORT_INSERTION_CHECK_ONLY or $APT_NO_SORT_INSERTION to change 
behavior of automatically inserted sorts

 Set $APT_SORT_INSERTION_CHECK_ONLY
– The inserted sort operators only VERIFY that the data is sorted
• If data is not sorted properly at runtime, the job aborts
• Recommended only on a per-job basis during performance tuning


Set $APT_NO_SORT_INSERTION to stop
inserted sorts entirely

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