Re: [HACKERS] Point in Time Recovery

Well that is interesting :_)


Here is what I am doing on the removal front (I am keeping pg_xlog *now*):

$ cd $PGDATA
$ pg_ctl stop
$ ls|grep -v pg_xlog|xargs rm -rf

The contents of the archive directory just before recovery starts:

$ ls -l $PGDATA/../7.5-archive
total 49212
-rw-------    1 postgres postgres 16777216 Jul 22 14:59
000000010000000000000000
-rw-------    1 postgres postgres 16777216 Jul 22 14:59
000000010000000000000001
-rw-------    1 postgres postgres 16777216 Jul 22 14:59
000000010000000000000002

But here is recovery startup log:

LOG:  database system was shut down at 2004-07-22 14:58:57 NZST
LOG:  starting archive recovery
LOG:  restore_command = "cp /data1/pgdata/7.5-archive/%f %p"
cp: cannot stat `/data1/pgdata/7.5-archive/00000001.history': No such
file or directory
LOG:  restored log file "000000010000000000000000" from archive
LOG:  checkpoint record is at 0/A4D3E8
LOG:  redo record is at 0/A4D3E8; undo record is at 0/0; shutdown TRUE
LOG:  next transaction ID: 496; next OID: 17229
LOG:  archive recovery complete
LOG:  database system is ready

regards

Mark

Tom Lane wrote:

>
>Huh?  It works fine.
>
>The bit you may be missing is that if you blow away $PGDATA including
>pg_xlog/, you won't be able to recover past whatever you have in your WAL
>archive area.  The archive is certainly not going to include the current
>partially-filled WAL segment, and it might be missing a few earlier
>segments if the archival process isn't speedy.  So you need to keep
>those recent segments in pg_xlog/ if you want to recover to current time
>or near-current time.
>
>
>
>