The SET-COMPRESSION statement turns the SM2U1 compression function on or off. The statement for compression can be specified when the SM2 output files are merged. As a result of compression, a number of cycles in the input files are merged into a single cycle in the output file. The monitoring cycle of the output file is an hour. The output file corresponds to an SM2 output file written by SM2 in the same period of time with a monitoring cycle of an hour.
Format
SET-COMPRESSION |
COMPRESSION = *ON / *OFF |
Operands
COMPRESSION =
Specifies whether the compression function is turned on or off.
COMPRESSION = *ON
The compression function is turned on.
COMPRESSION = *OFF
The compression function is turned off.
Restrictions
In SM2R1 report 74 (report group PCS) cannot be output with a compressed file.
In the compressed file, only groups of monitored objects present for the whole hour in the uncompressed file are output. Groups of monitored objects that would not be output by SM2 in an offline cycle of an hour in the same time period are not included either.
If there are missed records in the uncompressed file, even more records are missing in the compressed file. It is essential to avoid missed records.
Record 66 is not compressed (monitoring data for the QUEUE-TRANSITION).
Record 67 (monitoring data for MSCF) is not compressed.
As a result of compression, there is not enough data for an accurate bottleneck analysis, since existing maximum and minimum values are smoothed out. Thus, the compressed file is suitable for long-term statistics and trend analysis.
As a result of the compression of output files with the default monitoring cycle of 150 seconds, a compression factor of approximately 15 to 20 is achieved. The evaluation of a compressed file with SM2R1 is accelerated accordingly.