Experimenting with data subsets

Parallel query processing can provide the greatest performance gains on your largest tables and most I/O-intensive queries. Experimenting with different physical layouts on huge tables, however, is extremely time-consuming. Here are some suggestions for working with smaller subsets of data:

Working with subsets of data can help determine parallel query plans and the degree of parallelism for tables. One difference is that with smaller tables, sorts are performed in serial that would be performed in parallel on larger tables.