Re: [GENERAL] What locking mechanism is used for database backup and restore and Master-Slave Replication?
and to answer the question of the release date, I believe sometime around summer holiday. There is a schedule, but in reality things usually slip by couple weeks, especially when you add quite few not so trivial patches like replication. -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
Re: [GENERAL] What locking mechanism is used for database backup and restore and Master-Slave Replication?
2010/1/22 John Mitchell : > When is the new version of postgres (8.5) scheduled to be released as the > latest stable version? there will be no 8.5. It was decided to name it 9.0. -- GJ -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
Re: [GENERAL] What locking mechanism is used for database backup and restore and Master-Slave Replication?
When is the new version of postgres (8.5) scheduled to be released as the latest stable version? Thanks, John 2010/1/21 Grzegorz Jaśkiewicz > depends on what sort of replication you are going to use really. > Most are based on triggers. So they have a bit more impact on > performance. As far as locking goes, postgresql is very conservative > with locks, ie - it won't abuse them, unlike for instance mysql. > So I don't know whether you are just worried about performance in > general, or locking in particular. But impact of likes of slony isn't > that big, but obviously once the new version is out - it will be even > less of a problem, since postgresql already produces transactional log > for recovering, and pretty much the same log is going to be used for > replication. > > > 2010/1/21 John Mitchell : > > So am I to presume that the current stable version of postgres (before > 8.5) > > does require extra locking? > > > > John > > > > 2010/1/21 Grzegorz Jaśkiewicz > >> > >> On Thu, Jan 21, 2010 at 1:12 PM, John Mitchell > >> wrote: > >> > Hi, > >> > > >> > In reading the documentation it states that the SQL dump backup does > not > >> > block other operations on the database while it is working. > >> yes, pg_dump opens serializable transaction thus guarantees data to be > >> the exact snapshot (as opposed to the default isolation level, which > >> is called 'read commited' not without reason). > >> > > >> > I presume that while a restore is occurring that no reads or updates > are > >> > allowed against the restored database. > >> nope, what restoring does, is just running all the commands in the > >> pg_dump (whether it is binary or textual). So as soon as the database > >> is created, it is treated just as any connection, thus allows you to > >> connect and use it. > >> > >> > >> > What locking mechanism is used for Master-Slave Replication? > >> > >> master slave that's introduced in what's to be 9.0 (aka 8.5), uses WAL > >> shipping. So it doesn't require any extra locking. > >> > >> > >> > >> -- > >> GJ > > > > > > > > -- > > John J. Mitchell > > > > > > -- > GJ > -- John J. Mitchell
Re: [GENERAL] What locking mechanism is used for database backup and restore and Master-Slave Replication?
depends on what sort of replication you are going to use really. Most are based on triggers. So they have a bit more impact on performance. As far as locking goes, postgresql is very conservative with locks, ie - it won't abuse them, unlike for instance mysql. So I don't know whether you are just worried about performance in general, or locking in particular. But impact of likes of slony isn't that big, but obviously once the new version is out - it will be even less of a problem, since postgresql already produces transactional log for recovering, and pretty much the same log is going to be used for replication. 2010/1/21 John Mitchell : > So am I to presume that the current stable version of postgres (before 8.5) > does require extra locking? > > John > > 2010/1/21 Grzegorz Jaśkiewicz >> >> On Thu, Jan 21, 2010 at 1:12 PM, John Mitchell >> wrote: >> > Hi, >> > >> > In reading the documentation it states that the SQL dump backup does not >> > block other operations on the database while it is working. >> yes, pg_dump opens serializable transaction thus guarantees data to be >> the exact snapshot (as opposed to the default isolation level, which >> is called 'read commited' not without reason). >> > >> > I presume that while a restore is occurring that no reads or updates are >> > allowed against the restored database. >> nope, what restoring does, is just running all the commands in the >> pg_dump (whether it is binary or textual). So as soon as the database >> is created, it is treated just as any connection, thus allows you to >> connect and use it. >> >> >> > What locking mechanism is used for Master-Slave Replication? >> >> master slave that's introduced in what's to be 9.0 (aka 8.5), uses WAL >> shipping. So it doesn't require any extra locking. >> >> >> >> -- >> GJ > > > > -- > John J. Mitchell > -- GJ -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
Re: [GENERAL] What locking mechanism is used for database backup and restore and Master-Slave Replication?
So am I to presume that the current stable version of postgres (before 8.5) does require extra locking? John 2010/1/21 Grzegorz Jaśkiewicz > On Thu, Jan 21, 2010 at 1:12 PM, John Mitchell > wrote: > > Hi, > > > > In reading the documentation it states that the SQL dump backup does not > > block other operations on the database while it is working. > yes, pg_dump opens serializable transaction thus guarantees data to be > the exact snapshot (as opposed to the default isolation level, which > is called 'read commited' not without reason). > > > > I presume that while a restore is occurring that no reads or updates are > > allowed against the restored database. > nope, what restoring does, is just running all the commands in the > pg_dump (whether it is binary or textual). So as soon as the database > is created, it is treated just as any connection, thus allows you to > connect and use it. > > > > What locking mechanism is used for Master-Slave Replication? > > master slave that's introduced in what's to be 9.0 (aka 8.5), uses WAL > shipping. So it doesn't require any extra locking. > > > > -- > GJ > -- John J. Mitchell
Re: [GENERAL] What locking mechanism is used for database backup and restore and Master-Slave Replication?
On Thu, Jan 21, 2010 at 1:12 PM, John Mitchell wrote: > Hi, > > In reading the documentation it states that the SQL dump backup does not > block other operations on the database while it is working. yes, pg_dump opens serializable transaction thus guarantees data to be the exact snapshot (as opposed to the default isolation level, which is called 'read commited' not without reason). > > I presume that while a restore is occurring that no reads or updates are > allowed against the restored database. nope, what restoring does, is just running all the commands in the pg_dump (whether it is binary or textual). So as soon as the database is created, it is treated just as any connection, thus allows you to connect and use it. > What locking mechanism is used for Master-Slave Replication? master slave that's introduced in what's to be 9.0 (aka 8.5), uses WAL shipping. So it doesn't require any extra locking. -- GJ -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
[GENERAL] What locking mechanism is used for database backup and restore and Master-Slave Replication?
Hi, In reading the documentation it states that the SQL dump backup does not block other operations on the database while it is working. I presume that while a restore is occurring that no reads or updates are allowed against the restored database. What locking mechanism is used for Master-Slave Replication? Thanks, John J. Mitchell
