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 |
Read more...
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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