Hi, On 2014-06-02 10:15:19 -0700, Jeff Janes wrote: > > > Also, pg_xlogdump -p .... insists on being given a start position. I > > would > > > be nice if it could just find the first file in the given directory. Any > > > reason it can't do that, other than just that no one implemented it yet? > > > > It actually should accept getting a file passed instead of -s/-e. > > pg_xlogdump [OPTION]... [STARTSEG [ENDSEG]] > > That doesn't work for you? > > > > The STARTSEG does not seem to be optional, unless you specify both -p and > -s. I don't think there is a very good command-line synopsis for such > conditional dependencies--I think you are following the tradition here, in > that if something is optional under any normal circumstances then it is put > in brackets.
Maybe I have misunderstood what you actually want. You said: > I would be nice if it could just find the first file in the given > directory. You mean it should scan the pg_xlog directory and find the numerically oldest segment and start to decode from there? > If I give for STARTSEG a path to the data directory or the pg_xlog > directory instead of to a specific xlog file then I get bizarre error > messages like: > > pg_xlogdump: FATAL: could not find file "000000DA00C2C91500000080": No > such file or directory > (There is no timeline DA, nor C2C915 segments). So STARTSEG cannot be a > directory, which makes sense though the error message could be better. Hm. Yes, that's clearly suboptimal. Will look if I can make it return a more sensible error message. > If I specify the full path of the first real log file as STARTSEG, it > works. But it is annoying to have to figure out what the first valid file > in the directory is, then hope it hasn't changed while I type the command. > It is less annoying on an idle system or a snapshot, but it even there I'd > rather not provide information that can be safely inferred. I don't think it actually can be safely inferred in a trivial manner... I guess a mode that reads the control file and starts with values - including the timelineid - from there would be helpful. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
