Subject Re: [ib-support] When do FB/IB 'flush' to disk?
Author Ann W. Harrison
Paul Schmidt wrote:
> > > The function is "FlushFileBuffers".
> >

Phil Shrimpton wrote:

> > Would this be easy to implement in Firebird (for those of us that are
> > C impaired),

It would not be very difficult, but not so easy that I want to
hold RC2 or FB1 for it.

> > and if so when should it call it, and how often.
> > The two options that come to my mind are "Every Nth Commit" or "Every
> > Nth Second"

Paul Schmidt wrote:

>It would make sense to have this every commit, ... By decreasing time
>between commits, you increase execution time, but decrease risk.

Err, that's pretty much what the synch write does now. Remember
that Firebird has a write-back cache, not a write-through cache.
That means that pages remain in cache until they must be written,
which ordinarily means on commit. I doubt that you would see
significant difference in performance between "async on commit"
and "sync" writes.

>Now as for the C code, it depends on whether they use Windows
>style file handling,

Windows. In general, the engine uses the native file handling for
its platform - Netware, VMS, et al.


We have answers.