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.

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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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