SAS uses UNIX system
calls for your operating environment to get the statistical information
from FULLSTIMER. The datetime stamp is listed in the output. You can
change the behavior and format of the statistical information by using
the STIMFMT system option.
The following is an
example of FULLSTIMER output:
FULLSTIMER Output
NOTE: SAS initialization used:
real time 0.84 seconds
user cpu time 0.03 seconds
system cpu time 0.03 seconds
Memory 236k
OS Memory 5672k
Timestamp 3/16/2011 9:13:39 AM
Page Faults 37
Page Reclaims 0
Page Swaps 0
Voluntary Context Switches 1336
Involuntary Context Switches 1
Block Input Operations 39
Block Output Operations 0
Note: If both FULLSTIMER and STIMER
system options are set, the FULLSTIMER statistics are written to the
log.
FULLSTIMER displays
the following statistics:
Description of FULLSTIMER Statistics
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the amount of real time
(clock time) that is spent to process the SAS job. Real time is also
referred to as elapsed time.
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the CPU time that is
spent in the user program.
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the CPU time that is
spent to perform operating system tasks (system overhead tasks) that
support the execution of your SAS code.
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the amount of memory
required to run a step.
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the largest amount of
operating system memory that is available to SAS during the step.
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the date and time that
a step was executed.
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the number of pages
that SAS tried to access but were not in main memory and required
I/O activity.
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the number of pages
that were accessed without I/O activity.
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the number of times
a process was swapped out of main memory.
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Voluntary Context Switches
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the number of times
that the SAS process had to pause because of a resource constraint
such as a disk drive.
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Involuntary Context
Switches
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the number of times
that the operating system forced the SAS session to pause processing
to allow other process to run.
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the number of I/O operations
that are performed to read the data into memory.
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the number of I/O operations
that are performed to write the data to a file.
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For more information
about these statistics, see the man pages for the
getrusage()
and
times()
UNIX
system calls.
Note: Starting in SAS 9, some procedures
use multiple threads. On computers with multiple CPUs, the operating
system can run more than one thread simultaneously. Consequently,
CPU time might exceed real time in your FULLSTIMER output. For example,
a SAS procedure could use two threads that run on two separate CPUs
simultaneously. The value of CPU time would be calculated as the following:
CPU1 time + CPU2 time = total CPU time
1 second + 1 second = 2 seconds
Because CPU1 can run
a thread at the same time that CPU2 runs a separate thread for the
same SAS process, you can theoretically consume 2 CPU seconds in 1
second of real time.