Juho Tykkälä wrote:
Stephan van Loendersloot (LIST) kirjoitti:
Juho Tykkälä wrote:
<snip>
Why I ask is: If I'm going to add more features to my software,
which uses Derby database, and these features need database
structural changes, how can I update my customer's old software
versions without touching the data inside their databases. Just
need to add few columns more and don't want to clear data inside
database.
<snip>
Hi Juho,
You can use the same statements that you applied on your development
database to update your customers' databases. Just be aware of common
pitfalls when altering databases on productions systems, though.
<snip>
Hi Stephan,
Yes, I know alter table.
What I meant was: Is this possible by only moving and merging files
located at database/seg0/ directory? If it is, it would be much more
easier because I could update database changes among
other files using just "plain installation script" or other installer.
Hi Juho,
Sorry, but that's not possible. Even if it were, then the database would
have to be made aware of changes in the filesystem, or perform some sort
of scanning to be able to recognize and integrate changes.
Besides, files that are in use by the database may be locked by the
operating system while being read from or written to..
Guess you'll have to stick to regular updates.
Regards,
Stephan.
