Re: File Fragmentation - Mailing list pgsql-general

From jg
Subject Re: File Fragmentation
Date
Msg-id 44a4-5149cc00-3-6b8b4580@242648327
Whole thread Raw
In response to Re: File Fragmentation  (Vick Khera <vivek@khera.org>)
Responses Re: File Fragmentation
List pgsql-general
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


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