I'm in a similar position, cloning a database multiple times to provide development and qa databases for multiple groups. A feature desired by Clark would greatly help many people with their development and qa databases. On the other hand, I imagine, a feature like this would not be easy to develop, and it is useful for many but not all the users. So I doubt we can have it any time soon. On Sat, 2011-11-12 at 16:40 -0500, Clark C. Evans wrote: > Hello all! > > Our company has some headaches in our application development > and deployment process. The chief problem is, "creating stages", > which to this audience is, cloning a database efficiently, > making and testing a few changes, perhaps recording the > differences between databases, and then dropping the database. > > I'm eternally grateful for someone who pointed out that we > should be using "CREATE DATABASE ... WITH TEMPLATE". However, > this has two big disadvantages. First, it only works if you > can kick the users off the clone. Secondly, it still takes > time, uses disk space, etc. We have some big databases. > > I was also thinking about using ZFS with PostgreSQL to do > some sort of copy-on-write. However, this would require me > to spawn a whole *new* PostgreSQL instance. In both of these > cases, you lose your cache... > > So, I was wondering... could PostgreSQL grow the ability to > "CLONE" a database by re-using existing file system blocks, > sharing them across databases? This would perhaps be fast, > keep the shared memory cache relevant for both the old copy > and the clone, and remove WAL overhead. Then, if the block > has to be edited, it'd be cloned in memory, and the clone > would be flushed. > > I'm just imagining a world where "deploying" a new version > of our software that makes very small catalog changes and > tweaks a few rows would be... quick. Quick to try, check, > test, and even deploy on live servers. > > Best, > > Clark > -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
