Question about CPUAFFINITYMODE and CPUAFFINITYSET

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  Hibiki Vertica Employee Employee

  October 2022

  That percentage is used to define which CPU will be used by the Resource Pool. For example, Vertica database is running on the server that has 4 CPUs and it creates 2 Resource Pools with CPUAFFINITYSET parameter as below:

  CREATE RESOURCE POOL rp1 CPUAFFINITYMODE SHARED CPUAFFINITYSET '80%';
  CREATE RESOURCE POOL rp2 CPUAFFINITYMODE SHARED CPUAFFINITYSET '80%';
  

  We can see the information of the assigned CPUs used by each Resource Pool in resource_pool_status:

  => SELECT pool_name, cpu_affinity_mode, cpu_affinity_set, TO_BITSTRING(cpu_affinity_mask::VARBINARY) cpu_affinity_mask FROM resource_pool_status WHERE pool_name LIKE 'rp%' ORDER BY 1;
  
   pool_name | cpu_affinity_mode | cpu_affinity_set | cpu_affinity_mask
  -----------+-------------------+------------------+-------------------
   rp1       | SHARED            | 80%              | 00110111
   rp2       | SHARED            | 80%              | 00110111
  

  In this case, both Resource Pool use CPU 0, 1, 2.

  You can see another example in the product documentation as below:
  https://www.vertica.com/docs/12.0.x/HTML/Content/Authoring/SQLReferenceManual/SystemTables/MONITOR/RESOURCE_POOL_STATUS.htm#Examples

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