Re: Does a commit cause a checkpoint?

"Sybrand Bakker" <gooiditweg_at_sybrandb.demon.nl> wrote in message news:6q94fvg3lj5r8fun5gv80ms6p00pe3ltcn_at_4ax.com...
> On Thu, 19 Jun 2003 20:57:52 GMT, "Ryan" <rgaffuri_at_cox.net> wrote:
>
> >if that is the case, then my question isnt as bad as the flamer
suggested.
> >If LGWR and DBWR are independent processes, how does oracle ensure that
if
> >its being written by DBWR that it has already been written by LGWR.
>
>
> DBWR and LGWR *communicate* by means of interprocess communication.
>
>
> Sybrand Bakker, Senior Oracle DBA
>
> To reply remove -verwijderdit from my e-mail address

hmmm... figured it was something like that. So Im assuming there is a latch that lgwr aquires which tells dbwr do not write xyz to the datafile, until Im finished. DBWR polls the latch. Is there a latch and if so what is the name? Or does it just use inter-session communication? like synchronization etc...

Is this the log synch wait I see when I run statspack? dbwr is waiting for LGWR to write the blocks to the redo log before DBWR can go? Im assuming it can also be caused if you have your datafiles on the same mount point as your redo logs and you can only write to either datafiles or redo logs at the same time. Received on Thu Jun 19 2003 - 17:31:42 CDT