After the total after-image data written for four, separate one-hour periods is determined, the sizing calculations described in the following table are performed.

Table 1. After-image extent sizing calculations (hourly data)
Description Measurement/estimate
Average after-image data generated in one typical work hour 72.5MB, which is the average of the following:
  • 70MB in hour 1
  • 67MB in hour 2
  • 79MB in hour 3
  • 74MB in hour 4
OpenEdge Replication after-image overhead 50%, or 1.5 multiplier
Number of processing hours during a typical workday 16 hours per day
Number of processing hours during the typical workweek 80 (16 hours per day x 5 days)
Estimate of after-image data generated in one day

1160MB, or 1.13GB

(72.5MB x 16 hours per day)
Estimate of after-image data generated in one workweek 5800MB, or 5.66GB (1160MB x 5 days)
Estimate of after-image data generated in one hour with OpenEdge Replication overhead 109MB (72.5MB x 1.5)
Estimate of after-image data generated in one day with OpenEdge Replication overhead 1740MB (1160MB x 1.5)
Estimate of after-image data generated in one workweek with OpenEdge Replication overhead 8700MB (1740MB x 5 days)
Single fixed after-image extent size 450MB (109MB x 4 hours)
Total number of after-image extents necessary to handle one week of processing 19 extents (8700MB / 450MB)