DB Record Length Distribution report
The DB Record Length Distribution report that is generated by the Database Tuning Statistics function provides information about the distribution of database record length.
The following figure provides an example of the DB record length distribution report.
IMS HIGH PERFORMANCE UNLOAD "DB RECORD LENGTH DISTRIBUTION" PAGE: 1
5655-E06 DATE: 06/01/2021 TIME: 20.09.01 FABHC00 - V1.R2
DATABASE RECORD LENGTH DISTRIBUTION FOR DB=HDAM0010
LENGTH NBR DB-R PCT CUM PCT
---------------------------------------------------
<= 500 349 7.80 7.80
<= 550 740 16.54 24.35
<= 600 264 5.90 30.25
<= 650 1,355 30.29 60.55
<= 700 260 5.81 66.36
<= 750 551 12.32 78.68
<= 800 176 3.93 82.62
<= 850 329 7.35 89.98
<= 900 113 2.52 92.50
<= 950 82 1.83 94.34
<= 1000 81 1.81 96.15
<= 1050 34 .76 96.91
<= 1100 32 .71 97.62
<= 1150 12 .26 97.89
<= 1200 18 .40 98.30
<= 1250 9 .20 98.50
<= 1300 7 .15 98.65
<= 1350 4 .08 98.74
<= 1400 5 .11 98.85
<= 1450 3 .06 98.92
<= 1500 3 .06 98.99
<= 1600 1 .02 99.01
<= 1700 1 .02 99.03
<= 1800 3 .06 99.10
<= 1900 4 .08 99.19
<= 2000 6 .13 99.32
<= 2500 7 .15 99.48
<= 3000 7 .15 99.64
<= 3500 3 .06 99.70
<= 4000 5 .11 99.82
<= 5000 2 .04 99.86
<= 6000 2 .04 99.91
<= 7000 2 .04 99.95
<= 8000 2 .04 100.00
The statistics in the report are printed only if you request the generation of a DB Record Length Distribution report with your own definition of the database record length ranges. You can make this request by providing control cards in the HSSRLDEF data set (for more information, see HSSRLDEF input data set for Database Tuning Statistics).
The reported database record length includes the size of the segment prefixes and the size of the segment data as stored on DASD (for compressible segment, the size of the segment data reflects the size of the compressed segment). The table contains the number, the percentage, and the accumulated percentage of database records that are in the user-defined ranges of database record length.
When computing database record lengths, HSSR Engine takes into account only the database segments that have been retrieved by the application program or utility. The statistics modules of HSSR Engine are not aware of any database records or database segments that have not been retrieved.