Hi. Thanks for the quick and definitive answers to my questions.
The information you provided will save me from wasting time and
energy trying to see how far I could get otherwise. Thanks very much.
Janet
Tom Lane wrote:
> Janet Jacobsen <jsjacobsen@lbl.gov> writes:
>
>> Is it possible to create a database cluster on a machine that
>> has write access to the shared file system, shut down the
>> Postgres server on that machine, and then start up the
>> Postgres server on the machine that cannot write to the
>> shared file system, and thereafter, *only query* the database.
>>
>
> No. The pid file is only the first and smallest problem you'd run into
> with a read-only database filesystem.
>
> regards, tom lane
>
>
> On Fri, Jul 10, 2009 at 11:17 PM, Janet Jacobsen<jsjacobsen@lbl.gov> wrote:
>
>> > Is it possible to create a database cluster on a machine that
>> > has write access to the shared file system, shut down the
>> > Postgres server on that machine, and then start up the
>> > Postgres server on the machine that cannot write to the
>> > shared file system, and thereafter, *only query* the database.
>>
>
> Postgres isn't really designed to work this way. It expects to have
> write access and will occasionally still write stuff to disk even for
> read-only queries.
>
> It won't work even a little bit before 8.3. For 8.3 or later you could
> maybe make it work using vacuum freeze but there's no facility to
> verify that it's really frozen everything and you'll still be taken by
> surprise by queries which try to use temporary space for large sorts
> or commands which start transactions that you didn't realize were
> necessary.
>
> -- greg http://mit.edu/~gsstark/resume.pdf