How is a horizontal partitioning of a relation specified? How can a relation be put back together from a complete horizontal partitioning?

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 Horizontal partitioning divides a table into multiple tables. Each table then contains the same number of columns, but fewer rows. For example, a table that contains 1 billion rows could be partitioned horizontally into 12 tables, with each smaller table representing one month of data for a specific year.

The primary key is duplicated to allow the original table to be reconstructed. Using union operation to reconstruct them.




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