Thanks Amit, I understand now. Is there a way to know/predict how many prealocated segments will there be in a certain moment? What does it deppend on?
> I didn't quite understand what you mean by that... But anyways so do you > people think this sequence number overlap is "normal" ?
There is "no overlap" at all. The newer segments that you see are "pre-allocated" ones. They have not been written to yet.
From the "ls -l pg_xlog" output that you sent, it can be seen that segments starting from 000000010000000E000000A8 through 00000001000000100000007E have been pre-allocated (at that point of time) and 000000010000000E000000A7 is currently being written to. Just look at the modified times in your "ls -l" listing. 000000010000000E000000A7 has May 22 15:32 (the latest writes seem to have happened to this segment) whereas pre-allocated ones seem to have around May 22 12:05 to 12:15 (which are yet to be written to).
