Problem Note 37830: PROC PHREG uses additional memory beginning in SAS9.2
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Beginning with the SAS 9.2TS1m0 release, PROC PHREG uses more memory than previous releases such as SAS 9.1. There are two reasons for this change:
1) New computational subsystem
Due to the inclusion of the CLASS statement, PROC PHREG uses a new computational subsystem to handle the effects of the model which allows the specification of CLASS variables, main effects, cross effects, and nested effects. There is memory overhead associated with using the new computational subsystem. Although a particular invocation of PHREG may not contain a CLASS statement, the new computational subsytem is still used to handle the model effects.
2) Memory allocation for variable selection
With the accommodation of cross effects, the variable selection process must address the effect hierarchy. Extra memory is allocated to create structures for handling the effect hierarchy. This piece of memory should not be allocated unless the SELECT= option is specified.
Note that these two issues also affect experimental PROC TPHREG, which contains a CLASS statement, in SAS 9.1. The features of PROC TPHREG have been incorporated into PROC PHREG beginning in SAS 9.2 TS1m0 and, hence, PROC TPHREG has been phased out.
Operating System and Release Information
| Product Family | Product | System | SAS Release | |
| Reported | Fixed* | |||
| SAS System | N/A | z/OS | 9.2 TS1M0 | 9.2 TS2M3 |
| Microsoft® Windows® for 64-Bit Itanium-based Systems | 9.2 TS1M0 | 9.2 TS2M3 | ||
| Microsoft Windows Server 2003 Datacenter 64-bit Edition | 9.2 TS1M0 | 9.2 TS2M3 | ||
| Microsoft Windows Server 2003 Enterprise 64-bit Edition | 9.2 TS1M0 | 9.2 TS2M3 | ||
| Microsoft Windows XP 64-bit Edition | 9.2 TS1M0 | 9.2 TS2M3 | ||
| Microsoft® Windows® for x64 | 9.2 TS1M0 | 9.2 TS2M3 | ||
| Microsoft Windows Server 2003 Datacenter Edition | 9.2 TS1M0 | 9.2 TS2M3 | ||
| Microsoft Windows Server 2003 Enterprise Edition | 9.2 TS1M0 | 9.2 TS2M3 | ||
| Microsoft Windows Server 2003 Standard Edition | 9.2 TS1M0 | 9.2 TS2M3 | ||
| Microsoft Windows XP Professional | 9.2 TS1M0 | 9.2 TS2M3 | ||
| Windows Vista | 9.2 TS1M0 | 9.2 TS2M3 | ||
| 64-bit Enabled AIX | 9.2 TS1M0 | 9.2 TS2M3 | ||
| 64-bit Enabled HP-UX | 9.2 TS1M0 | 9.2 TS2M3 | ||
| 64-bit Enabled Solaris | 9.2 TS1M0 | 9.2 TS2M3 | ||
| HP-UX IPF | 9.2 TS1M0 | 9.2 TS2M3 | ||
| Linux | 9.2 TS1M0 | 9.2 TS2M3 | ||
| Linux for x64 | 9.2 TS1M0 | 9.2 TS2M3 | ||
| OpenVMS on HP Integrity | 9.2 TS1M0 | 9.2 TS2M3 | ||
| Solaris for x64 | 9.2 TS1M0 | 9.2 TS2M3 | ||
| Type: | Problem Note |
| Priority: | medium |
| Topic: | Analytics ==> Survival Analysis SAS Reference ==> Procedures ==> PHREG SAS Reference ==> Procedures ==> TPHREG |
| Date Modified: | 2010-06-29 12:37:53 |
| Date Created: | 2009-11-13 20:46:42 |