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