Shridhar Daithankar wrote:
Does 30% difference above count as significant?
No. It's Linux, we can look at the sources: there is no per-fd cache,
the page cache is global. Thus fsync() syncs the whole cache to disk.
A problem could only occur if the file cache is not global - perhaps a
per-nod
On Mon, Nov 17, 2003 at 12:46:34AM -0500, Bruce Momjian wrote:
> Tom Lane wrote:
> > > Do we know that having the background writer fsync a file that was
> > > written by a backend cause all the data to fsync? I think I could write
> > > a program to test this by timing each of these tests:
> >
>
On Monday 17 November 2003 11:16, Bruce Momjian wrote:
> Tom Lane wrote:
> > > Do we know that having the background writer fsync a file that was
> > > written by a backend cause all the data to fsync? I think I could
> > > write a program to test this by timing each of these tests:
> >
> > That m
Hannu Krosing wrote:
> Bruce Momjian kirjutas E, 17.11.2003 kell 03:58:
>
> >
> > OK, let me give you my logic and you can tell me where I am wrong.
> >
> > First, how many backend can a single write process support if all the
> > backends are doing insert/update/deletes? 5? 10? Let's assume
Bruce Momjian kirjutas E, 17.11.2003 kell 03:58:
>
> OK, let me give you my logic and you can tell me where I am wrong.
>
> First, how many backend can a single write process support if all the
> backends are doing insert/update/deletes? 5? 10? Let's assume 10.
> Second, once we change write
Tom Lane wrote:
> > Do we know that having the background writer fsync a file that was
> > written by a backend cause all the data to fsync? I think I could write
> > a program to test this by timing each of these tests:
>
> That might prove something about the particular platform you tested it
>
Tom Lane wrote:
> Bruce Momjian <[EMAIL PROTECTED]> writes:
> > Where am I wrong?
>
> I don't think any of this is relevant. There are a certain number of
> blocks we have to get down to disk before we can declare a transaction
> committed, and there are a certain number that we have to get down
Bruce Momjian <[EMAIL PROTECTED]> writes:
> Where am I wrong?
I don't think any of this is relevant. There are a certain number of
blocks we have to get down to disk before we can declare a transaction
committed, and there are a certain number that we have to get down to
disk before we can declar
Tom Lane wrote:
> Bruce Momjian <[EMAIL PROTECTED]> writes:
> > Tom Lane wrote:
> >> Seriously though, if we can move the bulk of the writing work into
> >> background processes then I don't believe that there will be any
> >> significant penalty for regular backends.
>
> > If the background write
