Обсуждение: PG equivalent of "mysqlhotcopy"?

Although mysqldump is the official solution, there's a fabulous perl
script "mysqlhotcopy" that simply copies the data from MySQL tables in
folders and restoring the data is as simple as copying the files back
to their /var/lib/mysql/data location.

I know about pg_dumpall, which creates a humongous SQL file, but is
there something equivalent in the postgresql world, like a
"pgsqlhotcopy" which copies data folders in a similar way as
mysqlhotcopy?

Thanks!

you can always try to write something on your own, using pitr and
pg_start_backup(), rsync, and friends.

http://www.postgresql.org/docs/8.3/static/continuous-archiving.html

> I know about pg_dumpall, which creates a humongous SQL file, but is
> there something equivalent in the postgresql world, like a
> "pgsqlhotcopy" which copies data folders in a similar way as
> mysqlhotcopy?

If you're lucky enough to be using a filesystem which supports atomic
snapshotting of directories (LVM and ZFS, I believe), you could just take
a snapshot of your entire Postgres data directory. See e.g.
http://lethargy.org/~jesus/archives/92-PostgreSQL-warm-standby-on-ZFS-crack.html

Note that mysqlhotcopy essentially works by forcibly locking all tables while
the copy is going on -- for any moderately big and busy server, this is a
huge problem.

Hi,

Le 30 juil. 09 à 15:34, Phoenix Kiula a écrit :
> I know about pg_dumpall, which creates a humongous SQL file, but is
> there something equivalent in the postgresql world, like a
> "pgsqlhotcopy" which copies data folders in a similar way as
> mysqlhotcopy?


Copying the raw data files of a live database only works under certain
conditions with PostgreSQL, in short you have to tell it about what
you're going to do for it to cooperate. That's pg_start_backup()
function and friends.

Now, the generic technique provided by PostgreSQL is called PITR,
Point In Time Recovery. You'll find ready to go software to drive
this, in order of personal preference :

  - walmgr from Skytools
     http://wiki.postgresql.org/wiki/Skytools#walmgr
     http://skytools.projects.postgresql.org/doc/walmgr.html
     https://developer.skype.com/SkypeGarage/DbProjects/SkyTools/WalMgr

  - pitrtools
     http://projects.commandprompt.com/public/pitrtools/

  - pg_standby (read carefully the 8.3 era behavior of this one)
     it's in the contribs

Those 3 solutions are packaged in debian and maybe some other
distributions or OS.

Regards,
--
dim