pgsql/src/backend/storage/file (fd.c)

Date: Tuesday, June 13, 2000 @ 23:19:25
Author: momjian

Update of /home/projects/pgsql/cvsroot/pgsql/src/backend/storage/file
from hub.org:/home/projects/pgsql/tmp/cvs-serv84221/pgsql/src/backend/storage/file

Modified Files:
fd.c

----------------------------- Log Message -----------------------------

> If read or write fails. Position will left the same. This
> situation is already tracked in File routines, but a little bit
> incorrectly.

> After small survey in Linux kernel code, I am not sure about
> it. New patch set pos to unknown in the case of read/write
> fails. And do lseek again.

> Here is the full patch for this. This patch reduce amount of
> lseek call ten ti mes for update statement and twenty times for
> select statement. I tested joined up date and count(*) select
> for table with rows > 170000 and 10 indices. I think this is
> worse of trying. Before lseek calls account for more than 5% o
> f time. Now they are 0.89 and 0.15 respectevly.
>
> Due to only one file modification patch should be applied in
> src/backedn/stora ge/file/ dir.

-- Sincerely Yours,
Denis Perchine