Re: BUG #1208: Invalid page header

Dear Tom,
I tried another load of the databases with fsync off (-F to
the postmaster), and I encountered at least one invalid page
header. Is there code in Postgres that handles the buffer cache
differently if fsync is off? Could this be a timing issue, since -F
does make PostgreSQL run faster?
BTW, I'll be out of the office for two weeks, so you'll hear
back from me around Labor Day. Thanks. --Bob

Tom Lane writes:
>
>
> "Robert E. Bruccoleri" <bruc(at)stone(dot)congenomics(dot)com> writes:
> > Besides a no optimization compilation of 7.4.3, what else
> > would you recommend to explore this problem further? Thanks. --Bob
>
> I really haven't the foggiest where to look :-( I don't actually
> believe that it's a spinlock problem; that would explain pages getting
> substituted for other pages, in whole or in part, but you showed at
> least one example where a page was just overwritten with garbage.
> That looks more like a memory-stomp problem (again, assuming that it's
> software) and so could be anywhere.
>
> Are you using any off-the-beaten-track code (contrib modules,
> non-btree indexes, non-mainstream data types)? That stuff is less
> well debugged than the mainstream ...
>
> regards, tom lane
>

+-----------------------------+------------------------------------+
| Robert E. Bruccoleri, Ph.D. | email: bruc(at)acm(dot)org |
| President, Congenair LLC | URL: http://www.congen.com/~bruc |
| P.O. Box 314 | Phone: 609 818 7251 |
| Pennington, NJ 08534 | |
+-----------------------------+------------------------------------+