Conserving resources when using PDQ

If applications make little use of queries that require parallel sorts and parallel joins, consider using the LOW setting for PDQ priority.

If the database server is operating in a multiuser environment, you might set MAX_PDQPRIORITY to 1 to increase interquery performance at the cost of some intraquery parallelism. A trade-off exists between these two different types of parallelism because they compete for the same resources. As a compromise, you might set MAX_PDQPRIORITY to some intermediate value (perhaps 20 or 30) and set PDQPRIORITY to LOW. The environment variable sets the default behavior to LOW, but the MAX_PDQPRIORITY configuration parameter allows individual applications to request more resources with the SET PDQPRIORITY statement.

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