Examine the parallelism parameters for you instance. Now examine the DSS_PLAN with parallel statement directives: Which two are true about the DSS_PLAN resource manager plan?

Question

Exhibits

Options

• AURGENT_GROUPS sessions will always be dequeued before sessions from other groups.
• BOTHER_GROUPS sessions are queued for maximum of six minutes.
• CETL_GROUP sessions can collectively consume 64 parallel execution servers before queuing starts
• DAn ETL_GRP sessions will be switched to URGENT_GROUPS if the session requests more than eight
• EURGENT_GROUP sessions will not be queued if 64 parallel execution servers are busy because their

• A
  72% (28)
• C
  15% (6)
• D
  5% (2)
• E
  8% (3)

Explanation

B: PARALLEL_QUEUE_TIMEOUT Parallel Queue Timeout When you use parallel statement queuing, if the database does not have sufficient resources to execute a parallel statement, the statement is queued until the required resources become available. However, there is a chance that a parallel statement may be waiting in the parallel statement queue for longer than is desired. You can prevent such scenarios by specifying the maximum time a parallel statement can wait in the parallel statement queue. The PARALLEL_QUEUE_TIMEOUT directive attribute enables you to specify the maximum time, in seconds, that a parallel statement can wait in the parallel statement queue before it is timed out. The PARALLEL_QUEUE_TIMEOUT attribute can be set for each consumer group. Not C: ETL_GROUP PARALLEL_TARGET_PERCENTAGE is 50%. So ETL_GROUP can only consume 32 servers. * If you want more per-workload management, you must use the following directive attributes: Management attributes control how a parallel statement is selected from the parallel statement queue for execution. You can prioritize the parallel statements of one consumer group over another by setting a higher value for the management attributes of that group. / PARALLEL_TARGET_PERCENTAGE / PARALLEL_QUEUE_TIMEOUT / PARALLEL_DEGREE_LIMIT_P1 * PARALLEL_DEGREE_LIMIT_P1 Degree of Parallelism Limit You can limit the maximum degree of parallelism for any operation within a consumer group. The degree of parallelism is the number of parallel execution servers that are associated with a single operation. Use the PARALLEL_DEGREE_LIMIT_P1 directive attribute to specify the degree of parallelism for a consumer group. The degree of parallelism limit applies to one operation within a consumer group; it does not limit the total degree of parallelism across all operations within the consumer group. However, you can combine both the PARALLEL_DEGREE_LIMIT_P1 and the PARALLEL_TARGET_PERCENTAGE directive attributes to achieve the desired control. * PARALLEL_TARGET_PERCENTAGE Parallel Target Percentage It is possible for a single consumer group to launch enough parallel statements to use all the available parallel servers. If this happens, when a high-priority parallel statement from a different consumer group is run, no parallel servers are available to allocate to this group. You can avoid such a scenario by limiting the number of parallel servers that can be used by a particular Use the PARALLEL_TARGET_PERCENTAGE directive attribute to specify the maximum percentage of the parallel server pool that a particular consumer group can use. The number of parallel servers used by a particular consumer group is counted as the sum of the parallel servers used by all sessions in that consumer group.

No community discussion yet for this question.