Re: postgres crash SOS

The first error message was what I got after postgres crashed and I
tried to make a dump, run vacuum or tried somthing else.
The second message I got when I tried to repaire the problem, so it
dous not matter because I did something wrong i see.

If I could choose I would use a linux server too, but if the partner
sais there is a windows server and you have to use that than there is
no discuss.

Why I was not specific how to this state came is I do not know.
I could not find anything about a power failer and disk space seemed
to be more than needed. There was entries in log for full virtual
memory.

2010/6/17 Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>:
> Felde Norbert <fenor77(at)gmail(dot)com> writes:
>> The message is the same for the original pg_clog/0003, the 0003
>> containing binary 0 and after pg_resetxlog:
>> pg_dump: Error message from server: ERROR:  could not access status of
>> transaction 3974799
>> DETAIL:  Could not read from file "pg_clog/0003" at offset 204800: No error.
>> pg_dump: The command was: COPY public.active_sessions_split (ct_sid,
>> ct_name, ct_pos, ct_val, ct_changed) TO stdout;
>> pg_dump: *** aborted because of error
>
>> If create the bigger 0003 containing 0 than I get that:
>> pg_dump: Error message from server: ERROR:  xlog flush request
>> 0/A19F5BF8 is not satisfied --- flushed only to 0/A02A1AC8
>> CONTEXT:  writing block 1149 of relation 1663/4192208/4192508
>> pg_dump: The command was: COPY public.history (historyid, adatkod,
>> elemid, userid, ido, actionid, targyid, szuloid, opvalue, longfield,
>> longtext) TO stdout;
>> pg_dump: *** aborted because of error
>
> I'm afraid this means you're screwed :-(.  Both of those symptoms imply
> that one part of the database storage is out of sync with another part:
> the first error says there are transaction IDs in the
> active_sessions_split table that don't exist in pg_clog, and the second
> error says that there are pages in the history table that were last
> updated by WAL records that don't exist in pg_xlog.  If there are two
> such errors, there are probably more.
>
> You weren't too specific about how you got into this state, but I
> suppose that it must have been a system crash or power failure.  Even
> then, you would not have gotten burnt if the filesystem and hardware
> did what they're supposed to do.  I suspect you have a setup wherein
> fsync() calls aren't being honored properly.  You may need to disable
> write caching on your disks, and/or switch to another filesystem or OS.
> (Personally I'd never run a database I cared about on Windows.)
>
>                        regards, tom lane
>