Each nodegroup is associated with a partitioning map, which is an array of 4 096 partition numbers. The partitioning map index produced by the partitioning function for each row of a table is used as an index into the partitioning map to determine partition on which a row is stored.
Figure 8 shows how the row with the partitioning key value (c1, c2, c3) is mapped to partitioning map index 2, which, in turn, references partition p5.
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The partitioning map can be changed, allowing the data distribution to be changed without modifying the partitioning key or the actual data. The new partitioning map is specified as part of the REDISTRIBUTE NODEGROUP command or API which uses it to redistribute the tables in the nodegroup. See Command Reference or Administrative API Reference for further information.