From: "Andrew Hammond" <andrew.george.hammond@gmail.com>
Subject: The Right Way to manage schemas in SCM systems
Date: 11 Aug 2006 08:05:34 -0700
Organization: http://groups.google.com
Lines: 31
Message-ID: <1155308733.994697.88060@h48g2000cwc.googlegroups.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"
User-Agent: G2/0.2
Complaints-To: groups-abuse@google.com
Injection-Info: h48g2000cwc.googlegroups.com; posting-host=207.219.45.62;
	posting-account=cSUlcA0AAABWACaPjo2Z9C0GBLTio512
To: pgsql-sql@postgresql.org

I've been trying to figure out a good way to manage schema change
control for a while now. Since I have a development background, I
really want to find some way to check the schema into a SCM system like
CVS (for example). Just using a pg_dump doesn't work very well becase
there's no guarantee of consistent ordering. One of the things I find
most useful with SCM systems is the ability to quickly spot changes. A
re-ordering within a single file makes for a lot of noise in the
deltas.

So far, the best idea I've come up with is the "file tree dump"
approach: get a list of every object in the database and then dump it
into a suitably named file. Finally, create a master file which
consists of only include lines. There are a couple of problems I can
see with this.

1) How to calculate the dependancy graph (or worse, dealing with RI
loops) to determine the right order to load things in isn't stupidly
obvious.
2) If I just script this in bash, without making any changes to
pg_dump, it doesn't happen in a single transaction.
3) No clever solution for relative vs absolute filenames (unless all
this goes into a tar file, but that format already exists and doesn't
solve my problem).

So my question is, does anyone have a better way of managing schemas in
SCM systems? And if not, is there a precieved value in the community
for a pg_dump --format scm_friendly option? (In which case I'll take
this thread over to hackers)

Drew