Hi,
I create a test cas on Linux:
postgres=# create table a (v int);
postgres=# create table b (v int);
Then a while(true) over the following script where 24577 and 24580 are the files of the tables a and b
#!/bin/sh
psql test -c 'insert into a select generate_series(1,100000,1);'
psql test -c 'insert into b select generate_series(1,100000,1);'
psql test -c 'checkpoint;'
/usr/sbin/filefrag -v 24577 24580
ls -lh 24577 24580
After few minutes, I got 100 extend by files.
The file fragmentation happens on Windows and Linux, too.
I not sure that the Wait IO on Windows is related to file fragmentation.
I try to find a way to analyse the situation.
JG