On 12/13/12 10:58 PM, Aristedes Maniatis wrote:
I understand that such a thing does not exist, and I need to write one
for my own needs. Does anyone have any pointers on where to start with
this? What I want is output of SQL commands to create the database,
tables, indices, etc and also insert statements for all the data. We
need to migrate some Derby data to another database and this appears
the simplest approach.
Would such a feature be a useful contribution toward the project, or
should we just work on this outside Apache?
Hi Ari,
This would definitely be a useful contribution. Doing your work in the
open in the community means that other contributors can warn you about
edge-cases you might not otherwise consider--and we will all learn from
your experience. Even if the committers don't incorporate your tool in
the product, you can still attach it to a JIRA for use by other developers.
If I understand correctly, you want to write a tool which copies one
Derby database to another. As I see it, there are 2 big pieces to this
project:
1) Generating the DDL to create all of the schema objects (tables,
views, UDTs, etc.). The existing dblook program does much of this work
already. However, more work needs to be done, particularly in the
following areas:
a) Generating DDL for GRANTs.
b) Sorting the table DDL by foreign key dependencies.
c) Dumping database properties.
d) Dumping NATIVE credentials.
2) Siphoning the data out of the source database into the target
database. The most efficient tool we have for that task is the
ForeignTableVTI attached to DERBY-4962. I recommend that you study that
JIRA. (Note that I hope to be able to check a version of ForeignTableVTI
into the product soon.) You will still need to generate INSERT
statements in the correct order; hopefully you will be able to re-use
the logic you write for (1b).
Before you start contributing, you will want to familiarize yourself
with the processes described here
http://db.apache.org/derby/derby_comm.html. In particular, you will want
to file an individual contributor license agreement (to protect Apache)
and you will want your company to file a corporate contributor license
agreement (to protect you). See http://www.apache.org/licenses/#clas
Thanks,
-Rick
Cheers
Ari
