SUPPORT / SAMPLES & SAS NOTES
Problem Note 38741: SAS® Scalable Performance Data Server Parallel Merge Join can give inconsistent results with a concurrency greater than 2
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It is important that your concurrency value not exceed 2 in order to avoid inconsistent merge results. A concurrency of 1 or 2 for parallel merge join still provides parallelism and has been shown to give optimal performance based on benchmark testing results.
Note:
- A concurrency of 1 means 2 threads working in parallel.
- A concurrency of 2 means 3 threads working in parallel.
Starting with SAS Scalable Performance Data Server release 4.52, concurrency is limited to 2 for parallel merge join.
Prior to SAS Scalable Performance Data Server release 4.52, SAS recommends setting CONCURRENCY=2 in the SQLOPTS=" " parameter option in the SPDSSERV.PARM file.
Operating System and Release Information
| Product Family | Product | System | Product Release | SAS Release | ||
| Reported | Fixed* | Reported | Fixed* | |||
| SPDS | Scalable Performance Data Server | Microsoft Windows Server 2003 Enterprise Edition | 4.4 | 4.52 | 9.2 TS2M3 | 9.2 TS2M3 |
| Microsoft Windows Server 2003 Standard Edition | 4.4 | 4.52 | 9.2 TS2M3 | 9.2 TS2M3 | ||
| Microsoft Windows XP Professional | 4.4 | 4.52 | 9.2 TS2M3 | 9.2 TS2M3 | ||
| Solaris for x64 | 4.4 | 4.52 | 9.2 TS2M3 | 9.2 TS2M3 | ||
| Linux for x64 | 4.4 | 4.52 | 9.2 TS2M3 | 9.2 TS2M3 | ||
| HP-UX IPF | 4.4 | 4.52 | 9.2 TS2M3 | 9.2 TS2M3 | ||
| 64-bit Enabled Solaris | 4.4 | 4.52 | 9.2 TS2M3 | 9.2 TS2M3 | ||
| 64-bit Enabled HP-UX | 4.4 | 4.52 | 9.2 TS2M3 | 9.2 TS2M3 | ||
| Linux | 4.4 | 4.52 | 9.2 TS2M3 | 9.2 TS2M3 | ||
| 64-bit Enabled AIX | 4.4 | 4.52 | 9.2 TS2M3 | 9.2 TS2M3 | ||
| Microsoft Windows Server 2003 Datacenter Edition | 4.4 | 4.52 | 9.2 TS2M3 | 9.2 TS2M3 | ||