
Hi,

 I am Suchindra Katageri and am working as a Software Engineer at
 Linuxlabs, Atlanta, GA.
 
 I am presently working on developing libraries to make postgresql
 run on a cluster. I was wondering if it was possible to force Database
 writes to stable storage, without messing up with the postgres code.
 e.g. force the PostgreSQL to write to stable storage after an INSERT
 command.

 Thanks in advance.
 
-- 
regards,
--suchindra


Sat, 8 Nov 2003 19:15:24 -0500 (EST)
suchindra@linuxlabs.com
Question for the developers.
suchindra@linuxlabs.com wrote:
> 
> Hi,
> 
>  I am Suchindra Katageri and am working as a Software Engineer at
>  Linuxlabs, Atlanta, GA.
>  
>  I am presently working on developing libraries to make postgresql
>  run on a cluster. I was wondering if it was possible to force Database
>  writes to stable storage, without messing up with the postgres code.
>  e.g. force the PostgreSQL to write to stable storage after an INSERT
>  command.

For stable storage, you mean disk storage?  You need fsync for that,
probably, but we already fsync our write-ahead log (WAL) on every
commit.

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

Sat, 8 Nov 2003 19:45:03 -0500 (EST)
Bruce Momjian <pgman@candle.pha.pa.us>
Re: Question for the developers.
suchindra@linuxlabs.com wrote:

> Hi,
> 
>  I am Suchindra Katageri and am working as a Software Engineer at
>  Linuxlabs, Atlanta, GA.
>  
>  I am presently working on developing libraries to make postgresql
>  run on a cluster. I was wondering if it was possible to force Database
>  writes to stable storage, without messing up with the postgres code.
>  e.g. force the PostgreSQL to write to stable storage after an INSERT
>  command.

I don't see how that would help you very far.

PostgreSQL holds disk buffers in a shared memory cache. And unless you 
modify that cache, it would not read from the file again if it thinks it 
knows the content already. How do you intend to remove pages from that 
shared buffer cache at the time, another cluster member modifies the 
same logical page?


Jan

-- 
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Mon, 10 Nov 2003 10:57:14 -0500
Jan Wieck <JanWieck@Yahoo.com>
Re: Question for the developers.