This makes it easier to callers of GetSegmentByPosition to determine if the segment is missing. Change-Id: I2d8546dddf07dcf790d2f7c08d308ed589b34f2f
We need to be able to update just remote_pieces column in DB. This is needed at least for repair process. Change-Id: I20dcc9b06babfefbbf102f32b1d14946379f26c2