This field specifies for how long the data should be kept in BAM data tables. The default value is 1 day
(denoted by 1d). Data will be removed from BAM data tables while summary generation as specified by
this field.
The value of this field should be an integer followed by a character; either h, d, or m.
These characters specify the time range as follows:
h- hour
d- day
m- month
For example:
1h means last hour's data should be retained.
2d means last two days' data should be retained.
6m means last six months' data should be retained.