showplan messages

showplan prints the degree of parallelism each time a table is accessed in parallel. The following example shows the messages for each table in the join in Figure 24-7:

Executed in parallel with a 2-way hash scan.
Executed in parallel with a 3-way partition scan.

showplan also prints a message showing the total number of worker processes used. For the query shown in Figure 24-7, it reports:

Executed in parallel by coordinating process and 6 worker processes.

See “showplan messages for parallel queries” for more information and Chapter 25, “Parallel Query Optimization,” for additional examples.