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Greenplum - Architecture and SQL by Leona Coffing, Tom Coffing

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Chapter 3 – Hashing and Data Distribution

“Speak in a moment of anger and you’ll deliver the greatest speech you’ll ever regret.”

- Anonymous

Distribution Keys Hashed on Unique Values Spread Evenly

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When you have a Distribution Key by Hash and the values in that column are unique, the data will spread perfectly evenly in your Greenplum system. This is because the data values in the Hash Key use a hashing formula. The formula is designed to be consistent and spread the data evenly.

Distribution Keys with Non-Unique Values Spread Unevenly

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When you ...

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