Storage and Other Overhead Considerations for Partitioning
Implications for Storage of Partitioning
The storage implications of partitioned tables and join indexes are minimal.
Each row in a partitioned table or join index has either 2 or 8 additional bytes in
its row header to store its internal partition number.
An empty partition occupies no space on disk, and a populated partition occupies only
2, 4, or 8 bytes more per row than the same rows would if they belonged to a nonpartitioned
table because a partition is just an ordering of the rows on an AMP.
There is no additional overhead accrued by inserting the first row into a partition.
Another way to say this is that there is no action required to create a partition.
Rows are just inserted in their partition/row hash/uniqueness order.
There is no additional overhead accrued by deleting the last row of a partition.
In other words, there is no additional action required to drop a partition. The last
row of a partition is just deleted in the same way as any other row.