IMC Serial Queries Run in Parallel on RAC

(Doc ID 2373556.1)

Last updated on APRIL 04, 2018

Applies to:

Oracle Database - Enterprise Edition - Version 12.2.0.1 and later
Information in this document applies to any platform.

Symptoms

Problem Summary
---------------------------------------------------
Query runs in parallel when it should be running in serial.

Problem Description
---------------------------------------------------
Parallel_degree_policy=manual

No parallel hint in query

No dop set on table or indexes

Instance = 1 on table and indexes

The table is in memory

This is RAC

Query will run in parallel

PX trace file shows:

 

kkopqSetForceParallelProperties: Hint:no >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Query: compute:yes forced:no forceDop:0
2018-03-02 13:31:57.521*:PX_Messaging:kxfp.c@19689:kxfpActiveInstList(begin):
Get instance list for state:open
2018-03-02 13:31:57.521*:PX_Messaging:kxfp.c@19819:kxfpActiveInstList(end):
groupName:[mib.state.mi.us] #instances=2 <<<<<<<<<<<<<<<<
kxfplist status:2 #insts:2
2018-03-02 13:31:57.521*:PX_Messaging:kxfp.c@20626:kxfpiinfo():
inst [cpus:mxslv:bc(MB) :pga_target(MB):type]
1 [32 :1280 :5984 :5120 :HUB]
2 [32 :1280 :6400 :5120 :HUB]
instance_id:1, cpu_count:32 #pg:1
instance_id:2, cpu_count:32 #pg:1
total cpu_count:64 #pg:2
kkopqInMemRacDOPAffinity: #nodes=2 - CapDOP=128 - Rounded from 1 to 2 - Capped?=no
Global Manual Dop: 2 - Rounded?: yes <<<<<<<<<<<<<<<<<<<<<<<<
kkopqSetDopReason: Reason why we chose this DOP is: table property. <<<<<<<<<<<<<<<<<table has dop=1 but this is a 2 node RAC system.
table property forces parallelism with dop=2

Cause

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