Re: [Firebird-devel] ODS version

Sorry to revert to an old question, but nobody seems to have asked this question... > On Dec 25, 2014, at 10:18 AM, Dimitry Sibiryakov wrote: > > Ok, let me simplify the question: > > I've created an engine that cannot work with databases, created by standard > engine. > Standard engine

Re: [Firebird-devel] ODS version

On 29/12/2014 07:16, Dimitry Sibiryakov wrote: > 28.12.2014 4:28, James Starkey wrote: >> I agree. That's how you understand it. But you are wrong. >No matter if I'm right or wrong. Just tell me the number. > No matter what number you use, Firebird will continue, improve and use that number.

Re: [Firebird-devel] ODS version

28.12.2014 4:28, James Starkey wrote: > I agree. That's how you understand it. But you are wrong. No matter if I'm right or wrong. Just tell me the number. > On Thursday, December 25, 2014, Dimitry Sibiryakov > wrote: > > Ok, let me simplify the question:

Re: [Firebird-devel] ODS version

I agree. That's how you understand it. But you are wrong. On Thursday, December 25, 2014, Dimitry Sibiryakov wrote: >Ok, let me simplify the question: > >I've created an engine that cannot work with databases, created by > standard engine. > Standard engine CAN work with databases crea

Re: [Firebird-devel] ODS version

Ok, let me simplify the question: I've created an engine that cannot work with databases, created by standard engine. Standard engine CAN work with databases created by my engine (if ODS check is changes a little). What ODS number I must use for databases created by my engine? -- WB

Re: [Firebird-devel] ODS version

24.12.2014 19:15, Jim Starkey wrote: > For example, if a new > index encoding is added, a new engine must be able to handle both the > old and new formats, but an old engine can't possibly understand the new > format. IMHO, this is an example of major change. > It well might mean version check

Re: [Firebird-devel] ODS version

On 12/24/2014 12:35 PM, Dimitry Sibiryakov wrote: > No, an older engine can't know what has changed, so there is no way it > can access a more recent minor ODS. > AFAIU, minor changes are minor because they don't need any special > treatment, they can > be just ignored by older engines. >

Re: [Firebird-devel] ODS version

24.12.2014 18:29, Leyne, Sean wrote: >> AFAIU, minor ODS changes are supposed to be backward compatible: >> additional fields in system tables, additional indexes and so on. Such >> changes >> raise minor ODS version, right? > > Nope. > > Compatibility is only guaranteed forward, not backwards

Re: [Firebird-devel] ODS version

24.12.2014 18:21, Jim Starkey wrote: > On 12/24/2014 11:04 AM, Dimitry Sibiryakov wrote: >> No, I asked exactly that. Older engines don't need new fields, they can >> work with new >> ODS easily. Newer engines need new fields, they cannot work with old ODS. >> That's how I >> understand it.

Re: [Firebird-devel] ODS version

>AFAIU, minor ODS changes are supposed to be backward compatible: > additional fields in system tables, additional indexes and so on. Such changes > raise minor ODS version, right? Nope. Compatibility is only guaranteed forward, not backwards. Sean ---

Re: [Firebird-devel] ODS version

On 12/24/2014 11:04 AM, Dimitry Sibiryakov wrote: > 24.12.2014 16:59, Mark Rotteveel wrote: >> On 24-12-2014 16:56, Dimitry Sibiryakov wrote: >>> 24.12.2014 16:39, Jim Starkey wrote: Sorry, that's backwards. Changes to the minor version are upwards compatible -- a new engine can work aga

Re: [Firebird-devel] ODS version

24.12.2014 16:59, Mark Rotteveel wrote: > On 24-12-2014 16:56, Dimitry Sibiryakov wrote: >> 24.12.2014 16:39, Jim Starkey wrote: >>> Sorry, that's backwards. Changes to the minor version are upwards >>> compatible -- a new engine can work against an older database. If a >>> change is backwards co

Re: [Firebird-devel] ODS version

On 24-12-2014 16:56, Dimitry Sibiryakov wrote: > 24.12.2014 16:39, Jim Starkey wrote: >> Sorry, that's backwards. Changes to the minor version are upwards >> compatible -- a new engine can work against an older database. If a >> change is backwards compatible, there is no reason to change the ODS

Re: [Firebird-devel] ODS version

On 24-12-2014 16:56, Dimitry Sibiryakov wrote: > 24.12.2014 16:39, Jim Starkey wrote: >> Sorry, that's backwards. Changes to the minor version are upwards >> compatible -- a new engine can work against an older database. If a >> change is backwards compatible, there is no reason to change the ODS

Re: [Firebird-devel] ODS version

24.12.2014 16:39, Jim Starkey wrote: > Sorry, that's backwards. Changes to the minor version are upwards > compatible -- a new engine can work against an older database. If a > change is backwards compatible, there is no reason to change the ODS > version at all. How SELECT NEW_FIELD FROM SYS

Re: [Firebird-devel] ODS version

24.12.2014 16:48, Mark Rotteveel wrote: > How would an older version now how to read the ODS if > something has changed? ODS is not only structures on database pages, but system tables as well. New fields are ignored on reading and filled with default values on writing, no?.. -- WBR, SD.

Re: [Firebird-devel] ODS version

On 24-12-2014 16:44, Dimitry Sibiryakov wrote: > 24.12.2014 16:36, Mark Rotteveel wrote: >> As far as I understand it, older engines won't be able to use newer ODS >> versions, even if it is only an increase in the minor version. > > Yes, this way is written isSupported() now. But it may be wro

Re: [Firebird-devel] ODS version

Sorry, that's backwards. Changes to the minor version are upwards compatible -- a new engine can work against an older database. If a change is backwards compatible, there is no reason to change the ODS version at all. On 12/24/2014 10:33 AM, Dimitry Sibiryakov wrote: > Hello, All. > >

Re: [Firebird-devel] ODS version

24.12.2014 16:36, Mark Rotteveel wrote: > As far as I understand it, older engines won't be able to use newer ODS > versions, even if it is only an increase in the minor version. Yes, this way is written isSupported() now. But it may be wrong from some POW. -- WBR, SD. --

Re: [Firebird-devel] ODS version

On 24-12-2014 16:33, Dimitry Sibiryakov wrote: > Hello, All. > > AFAIU, minor ODS changes are supposed to be backward compatible: > additional fields in > system tables, additional indexes and so on. Such changes raise minor ODS > version, right? > I.e. old engines for the same major

[Firebird-devel] ODS version

Hello, All. AFAIU, minor ODS changes are supposed to be backward compatible: additional fields in system tables, additional indexes and so on. Such changes raise minor ODS version, right? I.e. old engines for the same major version should work ok with databases created by newer engin