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11-25-2014
03:37 AM

11-25-2014
03:37 AM

I understand the PARTITION#Ln is used to denote a level in MLPPI.

What is the combined partitioning Expression ? Is this all the ranges specified in a MLPPI table. ?

How does the RowKey differ to the combined partition number.

Teradata's documentation states the following.

The combined partitioning expression for a table defines how rows are ultimately partitioned on each AMP. The result of the combined partitioning expression for specific values of the partitioning column is referred to as the combined partition number.

Thanks

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11-26-2014
03:36 AM

11-26-2014
03:36 AM

The combined partitioning expression is the PARTITION number, which is calculated on based on the number of PARTITION#Ln in each Level, basically a number between 1 and the product of the number of partitions in each level:

The RowKey is based on PARTITION, so there's no difference between single and multi-level PPI.

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12-04-2014
12:21 AM

12-04-2014
12:21 AM

Thanks Dieter your explanation has cleared it up for me. Knowing the combined partitioning expression is the partition Number makes everythng else I read now clear. Many Thanks

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12-05-2014
07:53 AM

12-05-2014
07:53 AM

Hi We are a Teradata 14.10 site. Is there any way to directly parition on a Varchar column in Teradata ? I want to partition on a multi billion table on a Varcr(18) column. Currrently there are approximately 8500 distinct values for this colun, so I can't specify a case statement large enough. If I specify the colums as patrtition on VARCHAR_COLUMN_NAME, Teradata cast the coulumn as Integer.

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12-06-2014
05:36 AM

12-06-2014
05:36 AM

How is this column accessed?

Using equality on a single value: *WHERE VarCharCol = 'value'*?