Chapter 6 - Partition Primary Index (PPI) Tables
“I saw an angel in the marble and carved until I set him free.”- Michelangelo
The Concept behind Partitioning a Table
- Each Table in Teradata has a Primary Index unless it is a NoPI table.
- The Primary Index is the mechanism that allows Teradata to physically distribute the rows of a table across the AMPs.
- AMPs Sort their rows by the Row-ID, so the system can perform a lightning fast Binary Search since the rows are in Row-ID Order.
- Partitioning merely tells the AMP to sort its tables’ rows by the Partition first, but then sort the rows by Row-ID within the partition.
- Partitioning queries will involve all AMPs, but partitioned tables are designed to prevent FULL Table Scans.
The basic concepts ...