|Hours limit a segment file can be open before being flushed
Approximate limit on the number of hours a segment file can be open for
writing before being flushed even if it is not full. (Full is set using
BLOCKS_PER_SEGMENT) Default: version < 1.4.x had 720,
1.4.x has 24.
BLOCKS_PER_SEGMENT for an example of this variable and