Re: [Firebird-devel] [SPAM] Re: Start transaction from base transaction
Em 06/05/2017 11:15, Vlad Khorsun escreveu: > 06.05.2017 15:15, livius wrote: >> >>> Yes, but we should avoid to write whole novels at SQL statements ;) >> >> Agree - but to fast chice is also not good > >Could you offer better syntax ? > >>> It have no sence (if i understand you :) ) >> Maybe, but it should be prohibited in code or designed to do not create >> wrong behavior > >I prefer second when possible. And this is one more reason for explicitly > export transaction snapshot. > The bad thing of this is that will be difficult to use the feature for debugging purposes, together with MON$ queries. >Also, we could disable to export and import snapshots at the same time and > it will make such cases impossible. I offer to go this way. > I think this would not be necessary when the good words for a SQL statement appears. Adriano -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
[Firebird-devel] [SPAM] Re: Start transaction from base transaction
06.05.2017 15:15, livius wrote: > >> Yes, but we should avoid to write whole novels at SQL statements ;) > > Agree - but to fast chice is also not good Could you offer better syntax ? >> It have no sence (if i understand you :) ) > Maybe, but it should be prohibited in code or designed to do not create > wrong behavior I prefer second when possible. And this is one more reason for explicitly export transaction snapshot. > You know if something is possible someone use it > and i mean: > base transaction > transaction 2 share base transaction > transaction 3 share base transaction > and someone try > transaction 4 share e.g. transaction 2 ;-) in this point it should share > base or do not alow it > but maybe heare are not any problem? So far, I see no problem (except of strange coding\design of such user application). Also, we could disable to export and import snapshots at the same time and it will make such cases impossible. I offer to go this way. Regards, Vlad -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
Re: [Firebird-devel] Start transaction from base transaction
Em 06/05/2017 09:15, livius escreveu: > >> Yes, but we should avoid to write whole novels at SQL statements ;) > > Agree - but to fast chice is also not good > >> It have no sence (if i understand you :) ) > Maybe, but it should be prohibited in code or designed to do not create > wrong behavior > You know if something is possible someone use it > and i mean: > base transaction > transaction 2 share base transaction > transaction 3 share base transaction > and someone try > transaction 4 share e.g. transaction 2 ;-) in this point it should share > base or do not alow it > but maybe heare are not any problem? > transaction 4 will start with the same snapshot started in transaction, transaction 2 and transaction 3. Adriano -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
Re: [Firebird-devel] Start transaction from base transaction
>Yes, but we should avoid to write whole novels at SQL statements ;) Agree - but to fast chice is also not good > It have no sence (if i understand you :) ) Maybe, but it should be prohibited in code or designed to do not create wrong behavior You know if something is possible someone use it and i mean: base transaction transaction 2 share base transaction transaction 3 share base transaction and someone try transaction 4 share e.g. transaction 2 ;-) in this point it should share base or do not alow it but maybe heare are not any problem? regards, Karol Bieniaszewski -Oryginalna wiadomość- From: Vlad Khorsun Sent: Saturday, May 6, 2017 11:55 AM To: firebird-devel@lists.sourceforge.net Subject: Re: [Firebird-devel] Start transaction from base transaction 06.05.2017 11:47, livius wrote: > Hi, > > for me name is confusing - beacause here can be two cases: > 1. Snapshot transaction is shared Looks like wrong\incomplete definition, as > 2. only view of database from its start point is shared and any > modification > caused by base snapshot and any sharing transaction is not shared between > transactions. we speak about this one. > Name must specify real maining. Yes, but we should avoid to write whole novels at SQL statements ;) > And question araise - is it possible that shared transaction with share > from > base transaction also possible to be shared? (i do not know if you > understand me) It have no sence (if i understand you :) ) Regards, Vlad -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel --- Ta wiadomość została sprawdzona na obecność wirusów przez oprogramowanie antywirusowe Avast. https://www.avast.com/antivirus -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
Re: [Firebird-devel] Start transaction from base transaction
06.05.2017 11:47, livius wrote: > Hi, > > for me name is confusing - beacause here can be two cases: > 1. Snapshot transaction is shared Looks like wrong\incomplete definition, as > 2. only view of database from its start point is shared and any modification > caused by base snapshot and any sharing transaction is not shared between > transactions. we speak about this one. > Name must specify real maining. Yes, but we should avoid to write whole novels at SQL statements ;) > And question araise - is it possible that shared transaction with share from > base transaction also possible to be shared? (i do not know if you > understand me) It have no sence (if i understand you :) ) Regards, Vlad -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
Re: [Firebird-devel] Start transaction from base transaction
Hi, for me name is confusing - beacause here can be two cases: 1. Snapshot transaction is shared 2. only view of database from its start point is shared and any modification caused by base snapshot and any sharing transaction is not shared between transactions. Name must specify real maining. And question araise - is it possible that shared transaction with share from base transaction also possible to be shared? (i do not know if you understand me) regards, Karol Bieniaszewski -Oryginalna wiadomość- From: Vlad Khorsun Sent: Friday, May 5, 2017 11:01 PM To: firebird-devel@lists.sourceforge.net Subject: Re: [Firebird-devel] Start transaction from base transaction 05.05.2017 21:10, Adriano dos Santos Fernandes wrote: > On 05/05/2017 14:43, Dmitry Yemanov wrote: >> 05.05.2017 20:01, Vlad Khorsun wrote: >>> %type snap_shot >>> snap_shot >>> : SNAPSHOT >>> | SNAPSHOT TABLE >>> | SNAPSHOT TABLE STABILITY >>> + | SNAPSHOT SHARING FROM >> SNAPSHOT BASED ON >> ? >> > Do you think with this words it's clear that the new transaction uses > the same snapshot used in , instead of incorrectly saying that it > will use as the snapshot for the new transaction? > > Thinking in these terms, I'm more inclined to adapt (renaming SHARING to > SHARED) Vlad's syntax to: > > SET TRANSACTION ISOLATION LEVEL SNAPSHOT SHARED FROM For me both variants are OK :) Probably native english speakers could offer something better and less ambiguous. Also, i offer to add additional rule for transaction which should export its snapshot data (it allows to avoid export by all transactions), something like: SET TRANSACTION ISOLATION LEVEL SNAPSHOT WITH SHARED SNAPSHOT Not sure i like it :) Regards, Vlad -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel --- Ta wiadomość została sprawdzona na obecność wirusów przez oprogramowanie antywirusowe Avast. https://www.avast.com/antivirus -- Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
