Re: Accessing Database files on a "read-only" medium...like a CD. - Mailing list pgsql-hackers

From Serguei Mokhov
Subject Re: Accessing Database files on a "read-only" medium...like a CD.
Date
Msg-id 06d801c14fb0$f7263800$5dd9fea9@gunn
Whole thread Raw
In response to Accessing Database files on a "read-only" medium...like a CD.  ("Kelly Harmon" <kelly.harmon@byers.com>)
Responses Re: Accessing Database files on a "read-only" medium...like a CD.
List pgsql-hackers
Kelly Harmon <kelly.harmon@byers.com> wrote in message news:9pr7f7$k0j$1@news.tht.net...
> SO...I dug around through the code a little and found where the error was
> coming from and changed the code so that if the open attempt with O_RDWR
> fails, the code tries again with O_RDONLY.  This was in md.c...in the mdopen
> function.
> 
> This did work....I was then able to open the database and do queries and
> whatnot.  Trying to insert into the table didn't give any errors...until I
> tried to select the record back out, at which time it started giving me
> errors such as:
> 
> ERROR:  cannot write block 7548 of pole: Permission denied
> 
> At that point, it seems that your screwed...in that even if you shut down
> postgres and restart it, somewhere it knows that that database has data that
> needs to be written to disk, and it refuses to continue until it does so.

Isn't it the WAL who 'remembers' this info?

--
Serguei A. Mokhov 



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