Subject | Re: [Firebird-Architect] Re[2]: [Firebird-devel] HEAD branch and ODS changes |
---|---|
Author | Ann Harrison |
Post date | 2003-07-30T14:59:16Z |
Hi Nicholay!
I'm concerned about making an ODS change in a minor version because
backing up and restoring databases is a significant hassle. In the
past, minor ODS changes were somtimes handled automatically - the engine
would upgrade the database when it was openned. That was a disaster in
several cases. There are a number of changes we could/should make to
the ODS, including long object names, index keys and other index
changes, variable length encoding of the runtime compression length ...
One small point. The header page can not overflow. There's no
provision for a second header page in a single database file. Yes, in a
multi-file database, there's one header page per file, but the first
header page is independent of the secondary ones. That's (part of) the
reason why the name of the third file is in the header of the second,
the fourth in the header of the third, usw.
Regards,
Ann
I'm concerned about making an ODS change in a minor version because
backing up and restoring databases is a significant hassle. In the
past, minor ODS changes were somtimes handled automatically - the engine
would upgrade the database when it was openned. That was a disaster in
several cases. There are a number of changes we could/should make to
the ODS, including long object names, index keys and other index
changes, variable length encoding of the runtime compression length ...
One small point. The header page can not overflow. There's no
provision for a second header page in a single database file. Yes, in a
multi-file database, there's one header page per file, but the first
header page is independent of the secondary ones. That's (part of) the
reason why the name of the third file is in the header of the second,
the fourth in the header of the third, usw.
Regards,
Ann