Re: [DOCS] [COMMITTERS] pgsql: Remove replicaiton FAQ item.
Marc G. Fournier wrote: > On Tue, 16 Nov 2004, Robert Treat wrote: > > > On Sunday 14 November 2004 16:33, Bruce Momjian wrote: > >> Log Message: > >> --- > >> Remove replicaiton FAQ item. > >> > >> Modified Files: > >> -- > >> pgsql/doc: > >> FAQ (r1.269 -> r1.270) > >> > >> (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/FAQ.diff?r1=1.269&r2= > >> 1.270) pgsql/doc/src/FAQ: > >> FAQ.html (r1.227 -> r1.228) > >> > >> (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/FAQ/FAQ.html.diff > >> ?r1=1.227&r2=1.228) > > > > While the answer may have been a little dated, this still seems to be an > > FAQ. > > Was there a discussion on removing this? If so I'll go read that, but ISTM > > this question should remain. > > agreed, this definitly does fall under a "Very FAQ" kinda thing ... > pointers to the various methods that are currently in use, at a minimum, > would be good ... Yep, big mistake my removing the replication FAQ item. I have re-added a new one: 4.21) What replication solutions are available? Though "replication" is a single term, there are two major replication technologies. Multi-master replication allows read/write queries to be sent to multiple replicated computers. Using this capability has a serious performance impact. Pgcluster is the most popular such solution available for PostgreSQL. Master-slave replication allows a single master to receive read/write queries, with slaves able to accept only read/SELECT queries. The most popular master-slave PostgreSQL replication solution is Slony. There are also commercial and hardware-based replication solutions available. -- Bruce Momjian| http://candle.pha.pa.us [email protected] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup.| Newtown Square, Pennsylvania 19073 ---(end of broadcast)--- TIP 6: Have you searched our list archives? http://archives.postgresql.org
Re: [DOCS] [COMMITTERS] pgsql: Remove replicaiton FAQ item.
Should the text include a mention of synchronous vs. asynchronous? Or does master-master imply synchronous? Regards, Jeff Davis On Sun, 2005-04-24 at 08:01 -0400, Bruce Momjian wrote: > Marc G. Fournier wrote: > > On Tue, 16 Nov 2004, Robert Treat wrote: > > > > > On Sunday 14 November 2004 16:33, Bruce Momjian wrote: > > >> Log Message: > > >> --- > > >> Remove replicaiton FAQ item. > > >> > > >> Modified Files: > > >> -- > > >> pgsql/doc: > > >> FAQ (r1.269 -> r1.270) > > >> > > >> (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/FAQ.diff?r1=1.269&r2= > > >> 1.270) pgsql/doc/src/FAQ: > > >> FAQ.html (r1.227 -> r1.228) > > >> > > >> (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/FAQ/FAQ.html.diff > > >> ?r1=1.227&r2=1.228) > > > > > > While the answer may have been a little dated, this still seems to be an > > > FAQ. > > > Was there a discussion on removing this? If so I'll go read that, but > > > ISTM > > > this question should remain. > > > > agreed, this definitly does fall under a "Very FAQ" kinda thing ... > > pointers to the various methods that are currently in use, at a minimum, > > would be good ... > > Yep, big mistake my removing the replication FAQ item. I have re-added a > new one: > > 4.21) What replication solutions are available? > > Though "replication" is a single term, there are two major replication > technologies. Multi-master replication allows read/write queries to be > sent to multiple replicated computers. Using this capability has a > serious performance impact. Pgcluster is the most popular such solution > available for PostgreSQL. Master-slave replication allows a single > master to receive read/write queries, with slaves able to accept only > read/SELECT queries. The most popular master-slave PostgreSQL > replication solution is Slony. There are also commercial and > hardware-based replication solutions available. > ---(end of broadcast)--- TIP 8: explain analyze is your friend
Re: [DOCS] [COMMITTERS] pgsql: Remove replicaiton FAQ item.
Jeff Davis wrote: Should the text include a mention of synchronous vs. asynchronous? Or does master-master imply synchronous? It shouldn't. It is possible to have synchronous replication without it being master<->master. Sincerely, Joshua D. Drake Regards, Jeff Davis On Sun, 2005-04-24 at 08:01 -0400, Bruce Momjian wrote: Marc G. Fournier wrote: On Tue, 16 Nov 2004, Robert Treat wrote: On Sunday 14 November 2004 16:33, Bruce Momjian wrote: Log Message: --- Remove replicaiton FAQ item. Modified Files: -- pgsql/doc: FAQ (r1.269 -> r1.270) (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/FAQ.diff?r1=1.269&r2= 1.270) pgsql/doc/src/FAQ: FAQ.html (r1.227 -> r1.228) (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/FAQ/FAQ.html.diff ?r1=1.227&r2=1.228) While the answer may have been a little dated, this still seems to be an FAQ. Was there a discussion on removing this? If so I'll go read that, but ISTM this question should remain. agreed, this definitly does fall under a "Very FAQ" kinda thing ... pointers to the various methods that are currently in use, at a minimum, would be good ... Yep, big mistake my removing the replication FAQ item. I have re-added a new one: 4.21) What replication solutions are available? Though "replication" is a single term, there are two major replication technologies. Multi-master replication allows read/write queries to be sent to multiple replicated computers. Using this capability has a serious performance impact. Pgcluster is the most popular such solution available for PostgreSQL. Master-slave replication allows a single master to receive read/write queries, with slaves able to accept only read/SELECT queries. The most popular master-slave PostgreSQL replication solution is Slony. There are also commercial and hardware-based replication solutions available. ---(end of broadcast)--- TIP 8: explain analyze is your friend ---(end of broadcast)--- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])
Re: [DOCS] [COMMITTERS] pgsql: Remove replicaiton FAQ item.
Joshua D. Drake wrote: > Jeff Davis wrote: > > Should the text include a mention of synchronous vs. asynchronous? Or > > does master-master imply synchronous? > > It shouldn't. It is possible to have synchronous replication without it > being master<->master. We could mention async vs sync but at the FAQ stage I think the multi-master/master-slave disinction is enough. Let's see what questions we get. -- Bruce Momjian| http://candle.pha.pa.us [email protected] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup.| Newtown Square, Pennsylvania 19073 ---(end of broadcast)--- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])
Re: [DOCS] [COMMITTERS] pgsql: Remove replicaiton FAQ item.
Quoting Bruce Momjian : > Joshua D. Drake wrote: > > Jeff Davis wrote: > > > Should the text include a mention of synchronous vs. > asynchronous? Or > > > does master-master imply synchronous? > > > > It shouldn't. It is possible to have synchronous replication > without it > > being master<->master. > > We could mention async vs sync but at the FAQ stage I think the > multi-master/master-slave disinction is enough. Let's see what > questions > we get. About all you can say is, it is not possible to implement synchronous master-master replication, because of conflict resolution of simultaneous transactions. -- "Dreams come true, not free." -- S.Sondheim, ITW ---(end of broadcast)--- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
Re: [DOCS] [COMMITTERS] pgsql: Remove replicaiton FAQ item.
Mischa Sandberg wrote: > Quoting Bruce Momjian : > > > Joshua D. Drake wrote: > > > Jeff Davis wrote: > > > > Should the text include a mention of synchronous vs. > > asynchronous? Or > > > > does master-master imply synchronous? > > > > > > It shouldn't. It is possible to have synchronous replication > > without it > > > being master<->master. > > > > We could mention async vs sync but at the FAQ stage I think the > > multi-master/master-slave disinction is enough. Let's see what > > questions > > we get. > > About all you can say is, it is not possible to implement synchronous > master-master replication, because of conflict resolution of > simultaneous transactions. You mean asynchronous master-master? There are some implementations (Sybase?, pgreplicator) that do this and have conflict resolution. -- Bruce Momjian| http://candle.pha.pa.us [email protected] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup.| Newtown Square, Pennsylvania 19073 ---(end of broadcast)--- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
Re: [DOCS] [COMMITTERS] pgsql: Remove replicaiton FAQ item.
Quoting Bruce Momjian : > Mischa Sandberg wrote: > > About all you can say is, it is not possible to implement > synchronous > > master-master replication, because of conflict resolution of > > simultaneous transactions. > > You mean asynchronous master-master? There are some implementations > (Sybase?, pgreplicator) that do this and have conflict resolution. Forgive my kibitz, then; perhaps my head has been stuck in sand a while. You're right, I forgot about the nicer bits of Sybase RepServer. Synchronous replication was scratched early in the project, because two-phase commit took too long across a dozen db servers. Pgreplicator advertises itself as a "store-and-forward asynch replica (sic) engine." (quoth http://pgreplicator.sourceforge.net/ ) -- "Dreams come true, not free." -- S.Sondheim, ITW ---(end of broadcast)--- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
