Re: [Firebird-devel] Tablespaces proposal
On 6/2/22 14:45, Adriano dos Santos Fernandes wrote: On 02/06/2022 08:08, Dimitry Sibiryakov wrote: Alex Peshkoff via Firebird-devel wrote 02.06.2022 13:01: It is "ALTER TABLE" which must be executed on replica. Otherwise you'll have problem with ALTER TABLE ADD FIELD. Is it impossible to analyze clauses of statement? Theoretically - yes. On practice it would require full Firebird SQL parser which is hard. Simpler would be to downgrade the "missing tablespace" error to a warning if the database is in replica mode or SQL is performed by Applier. Commands are replicated in text and executed in replica. The replica execution could ignore things when are running a replicated command. I see no difficulty there. Yes. Moreover - if ALTER TABLE has more clauses (like ADD FIELD) in addition to tablespaces related, only that tablespaces related clauses to be skipped. Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
Re: [Firebird-devel] Tablespaces proposal
On 02/06/2022 08:08, Dimitry Sibiryakov wrote: > Alex Peshkoff via Firebird-devel wrote 02.06.2022 13:01: >>> It is "ALTER TABLE" which must be executed on replica. Otherwise >>> you'll have problem with ALTER TABLE ADD FIELD. >> >> Is it impossible to analyze clauses of statement? > > Theoretically - yes. On practice it would require full Firebird SQL > parser which is hard. Simpler would be to downgrade the "missing > tablespace" error to a warning if the database is in replica mode or SQL > is performed by Applier. > Commands are replicated in text and executed in replica. The replica execution could ignore things when are running a replicated command. I see no difficulty there. Adriano Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
Re: [Firebird-devel] Tablespaces proposal
Alex Peshkoff via Firebird-devel wrote 02.06.2022 13:01: It is "ALTER TABLE" which must be executed on replica. Otherwise you'll have problem with ALTER TABLE ADD FIELD. Is it impossible to analyze clauses of statement? Theoretically - yes. On practice it would require full Firebird SQL parser which is hard. Simpler would be to downgrade the "missing tablespace" error to a warning if the database is in replica mode or SQL is performed by Applier. -- WBR, SD. Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
Re: [Firebird-devel] Tablespaces proposal
On 6/2/22 13:03, Dimitry Sibiryakov wrote: Alex Peshkoff via Firebird-devel wrote 02.06.2022 9:31: ALTER TABLE SET TABLESPACE is tablespaces-related DDL operator - i.e. it should not be executed on replica. Why conflict? It is "ALTER TABLE" which must be executed on replica. Otherwise you'll have problem with ALTER TABLE ADD FIELD. Is it impossible to analyze clauses of statement? Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
Re: [Firebird-devel] Tablespaces proposal
Alex Peshkoff via Firebird-devel wrote 02.06.2022 9:31: ALTER TABLE SET TABLESPACE is tablespaces-related DDL operator - i.e. it should not be executed on replica. Why conflict? It is "ALTER TABLE" which must be executed on replica. Otherwise you'll have problem with ALTER TABLE ADD FIELD. -- WBR, SD. Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
Re: [Firebird-devel] Tablespaces proposal
On 6/2/22 10:14, Ilya Eremin wrote: Hello! The last tablespaces proposal says: > Tablespaces are excluded from replication because it's physical layout > of a database and a replica may have another one. which means that tablespaces-related DDL operators won't be executed on a replica. But some conflicts may happen, for example, when a table is being moved to another tablespace via ALTER TABLE SET TABLESPACE. ALTER TABLE SET TABLESPACE is tablespaces-related DDL operator - i.e. it should not be executed on replica. Why conflict? If the tablespace doesn't exist in a replica, the statement will fail. The tablespace should be created in a replica before the statement is executed. It is possible to do it in another way: replicate tablespaces-related DDL to have the same set of tablespaces in a replica. The main problem here is the path to a tablespace file. It still can be absolute (will work if the path is also valid for a replica) or relative. It might be helpful to use directory aliases which can be set in some configuration file. And this is a downside - need to edit the configuration file on a replica(s). I do not think that such need is too big trouble. When one wants to combine replication and tablespaces that does require some efforts, including configuration. Which way is better for default behaviour? Would be good to hear opinions on this. Ideally use of tablespaces in replication should be configurable. One wants to quickly setup replica and forget about configuration issues, other wants to have exact copy including tablespaces. Someone else may use on replica another tablespaces set in order to optimize performance in different way from master database. Why force everyone to go same way? Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
Re: [Firebird-devel] Tablespaces proposal
Hello! The last tablespaces proposal says: > Tablespaces are excluded from replication because it's physical layout > of a database and a replica may have another one. which means that tablespaces-related DDL operators won't be executed on a replica. But some conflicts may happen, for example, when a table is being moved to another tablespace via ALTER TABLE SET TABLESPACE. If the tablespace doesn't exist in a replica, the statement will fail. The tablespace should be created in a replica before the statement is executed. It is possible to do it in another way: replicate tablespaces-related DDL to have the same set of tablespaces in a replica. The main problem here is the path to a tablespace file. It still can be absolute (will work if the path is also valid for a replica) or relative. It might be helpful to use directory aliases which can be set in some configuration file. And this is a downside - need to edit the configuration file on a replica(s). Which way is better for default behaviour? Would be good to hear opinions on this. -- Ilya Eremin Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
