Berkeley DB Family

Hi all,

I am working on FreeBsd and Berkeley DB 4.5.20

I have 2 kind of Btree databases and I want to measure the time for sequentially retrieving of all records.

1. Btrees with fixed record size of 128 Byte
2. Btrees with variable record size of around 630KB

when I sort the order of the Db's by time (time is the key in my DB's) the retrieving time is much shorter, so i have a higher performance.

but when I see the statistics structures:

for the 1. group after sorting by time the internal page fill factor and leaf pages fill factor are like 94% or 98% and overflow ff is 0%. so I an understand that this result in a higher performance.
and i have a shorter retrieving time than before sorting by time.


but for the 2. group that means for variable large record sizes I have shorter retrieving time (higher performance) before sorting by time but lower leaf and internal page fillfactor. and after sorting higher leaf and internal page ff but longer retrieving time. and the overflow ff is before and after sorting 99%.

so I am confuse , because I thought the higher leaf and internal page ff the higher performance,
but this is exactly the opposite for large variable record sizes. is that because of the high overflow page ff?

I would appreciate if some could explain it to me.

Regards
soudi