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2898849 - Query slower on 16.1 SP04 than on 16.1 SP02 - SAP IQ

Symptom

  • A query could run slower on SAP IQ 16.1 SP04 than on SAP IQ 16.1 SP02
  • On both versions, same IQ start up parameters are used 
  • On both versions, the query tree is the same 
  • On both versions, there are similar row counts and data distribution in the tables 
  • The main difference is, on SAP IQ 16.1 SP04, in the query plan, "Max. Active Parallel Threads" is always 1

On 16.1 SP02

From the query plan, CPU is high ~100%

#10 Root

Generated Result Rows    1,817
Estimated Result Rows  67,477
Est. Temp Space Used (Mb)    110.0
Act. Temp Space Used (Mb)    239.0
Threads used for executing local invariant predicates         1
Elapsed time 0:00:51

#5 Order By Node

Max. Possible Parallel Arms                                                   4
Max. Active Parallel Threads           3

#6 Order By Node

Max. Possible Parallel Arms                                                   4
Max. Active Parallel Threads          4

On 16.1 SP04

From the query plan, CPU is low ~25%

#10 Root

Generated Result Rows    1,784
Estimated Result Rows  67,477
Est. Temp Space Used (Mb)    112.0
Act. Temp Space Used (Mb)     74.5
Threads used for executing local invariant predicates         1
Elapsed time 0:02:16

#5 Order By Node

Max. Possible Parallel Arms                                                   4
Max. Active Parallel Threads          1

#6 Order By Node

Max. Possible Parallel Arms                                                   4
Max. Active Parallel Threads          1


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Environment

SAP IQ 16.1 SP 04

Product

SAP IQ 16.1

Keywords

CR821185; CR#821185; 821185; thread; threads; "Max. Active Parallel Threads";  Active; Parallel; "Max. Possible Parallel Arms"; Possible ; Parallel ; Arms; Max; -iqmt; iqmt; performance; slow , KBA , BC-SYB-IQ , Sybase IQ , Bug Filed

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