Re: Writing Commit Status hint bits (was Re: [HACKERS] Constant WAL replay)

2005-07-22 Thread Tom Lane
Simon Riggs <[EMAIL PROTECTED]> writes: > In general, the hint bits are good. In *some* cases, not. I still seek > control over that as a designer. > Specifically, the scenario I want to optimize is this: > - we load a table with lots of real time measurement data, as one child > out of a large nu

Re: Writing Commit Status hint bits (was Re: [HACKERS] Constant WAL replay)

2005-07-20 Thread Tom Lane
Simon Riggs <[EMAIL PROTECTED]> writes: > On Wed, 2005-07-20 at 09:24 -0400, Tom Lane wrote: >> We don't rely on any one write of them to work, but that doesn't mean >> that we can indefinitely postpone writing them. > OK, I think I understand where you're coming from now. Apparently not :-( > W

Re: [HACKERS] Constant WAL replay

2005-04-25 Thread Joshua D. Drake
What really interests me here: Where is you code located in order to make sure that this things can work reliably? We are integrated into the PostgreSQL backend. So they have to get a new PostgreSQL release from you for every minor upgrade, I assume at no cost? Yep :) Sincerely, Joshua D. Drake

Re: [HACKERS] Constant WAL replay

2005-04-25 Thread =?ISO-8859-1?Q?Hans-J=FCrgen_Sch=F6nig?=
Joshua D. Drake wrote: Joshua, This sounds interesting. If you don't use the WAL but a transaction log shipping - what does it mean in terms of PostgreSQL? Do you create your own transaction log? Yes. What really interests me here: Where is you code located in order to make sure that this thing

Re: [HACKERS] Constant WAL replay

2005-04-25 Thread Bruce Momjian
Joshua D. Drake wrote: > > > > > > Joshua, > > > > This sounds interesting. If you don't use the WAL but a transaction log > > shipping - what does it mean in terms of PostgreSQL? Do you create your > > own transaction log? > > Yes. > > > What really interests me here: Where is you code loca

Re: [HACKERS] Constant WAL replay

2005-04-25 Thread Joshua D. Drake
Joshua, This sounds interesting. If you don't use the WAL but a transaction log shipping - what does it mean in terms of PostgreSQL? Do you create your own transaction log? Yes. What really interests me here: Where is you code located in order to make sure that this things can work reliably? We

Re: [HACKERS] Constant WAL replay

2005-04-25 Thread =?ISO-8859-1?Q?Hans-J=FCrgen_Sch=F6nig?=
Neil Conway wrote: Hans-Jürgen Schönig wrote: The idea: We are looking for a way to implement a synchronous single-master / multiple slaves systems. Meanwhile we are able to serialize / deserialize WAL records and send them to a group communication system which transports those records to the sl

Re: [HACKERS] Constant WAL replay

2005-04-25 Thread =?ISO-8859-1?Q?Hans-J=FCrgen_Sch=F6nig?=
Joshua D. Drake wrote: Alvaro Herrera wrote: On Sun, Apr 24, 2005 at 08:10:34AM +0200, Hans-Jürgen Schönig wrote: The idea: We are looking for a way to implement a synchronous single-master / multiple slaves systems. Meanwhile we are able to serialize / deserialize WAL records and send them to a

Re: [HACKERS] Constant WAL replay

2005-04-24 Thread Bruce Momjian
Joshua D. Drake wrote: > >> > >>Very close. We don't use the WAL (yet, slated for probably 8.1) but we > >>do use a transaction log shipping method. So the implementation is > >>almost the same. > > > > > > Can you run queries on the slave? If so, how do you handle xid collisions? > > You can

Re: [HACKERS] Constant WAL replay

2005-04-24 Thread Joshua D. Drake
Very close. We don't use the WAL (yet, slated for probably 8.1) but we do use a transaction log shipping method. So the implementation is almost the same. Can you run queries on the slave? If so, how do you handle xid collisions? You can run any query that does not modify data on a replicated ta

Re: [HACKERS] Constant WAL replay

2005-04-24 Thread Bruce Momjian
Joshua D. Drake wrote: > Alvaro Herrera wrote: > > On Sun, Apr 24, 2005 at 08:10:34AM +0200, Hans-J?rgen Sch?nig wrote: > > > > > >>The idea: We are looking for a way to implement a synchronous > >>single-master / multiple slaves systems. > >>Meanwhile we are able to serialize / deserialize WAL

Re: [HACKERS] Constant WAL replay

2005-04-24 Thread Joshua D. Drake
Alvaro Herrera wrote: On Sun, Apr 24, 2005 at 08:10:34AM +0200, Hans-Jürgen Schönig wrote: The idea: We are looking for a way to implement a synchronous single-master / multiple slaves systems. Meanwhile we are able to serialize / deserialize WAL records and send them to a group communication sy

Re: [HACKERS] Constant WAL replay

2005-04-24 Thread Alvaro Herrera
On Sun, Apr 24, 2005 at 08:10:34AM +0200, Hans-Jürgen Schönig wrote: > The idea: We are looking for a way to implement a synchronous > single-master / multiple slaves systems. > Meanwhile we are able to serialize / deserialize WAL records and send > them to a group communication system which tra

Re: [HACKERS] Constant WAL replay

2005-04-24 Thread Alvaro Herrera
On Sun, Apr 24, 2005 at 11:41:17AM -0400, Tom Lane wrote: > Klaus Naumann <[EMAIL PROTECTED]> writes: > >> what. Allowing that to be turned off would be interesting for a number > >> of purposes, such as burning a database onto CD. > > > FWIW, Oracle suggests a "transportable tablespace" for this

Re: [HACKERS] Constant WAL replay

2005-04-24 Thread Tom Lane
Klaus Naumann <[EMAIL PROTECTED]> writes: >> what. Allowing that to be turned off would be interesting for a number >> of purposes, such as burning a database onto CD. > FWIW, Oracle suggests a "transportable tablespace" for this feature. > Which is a tablespace that is not written too and which

Re: [HACKERS] Constant WAL replay

2005-04-24 Thread Klaus Naumann
what. Allowing that to be turned off would be interesting for a number of purposes, such as burning a database onto CD. FWIW, Oracle suggests a "transportable tablespace" for this feature. Which is a tablespace that is not written too and which can be read by any database. Would that solve the pur

Re: [HACKERS] Constant WAL replay

2005-04-23 Thread Neil Conway
Hans-Jürgen Schönig wrote: The idea: We are looking for a way to implement a synchronous single-master / multiple slaves systems. Meanwhile we are able to serialize / deserialize WAL records and send them to a group communication system which transports those records to the slave database. BTW,

Re: [HACKERS] Constant WAL replay

2005-04-23 Thread Tom Lane
=?ISO-8859-1?Q?Hans-J=FCrgen_Sch=F6nig?= <[EMAIL PROTECTED]> writes: > We have toyed around with PostgreSQL's WAL structure and we are > wondering whether it is (theoretically) possible to replay WAL records > coming from a remote host while a system is working in read only mode. There's been so

[HACKERS] Constant WAL replay

2005-04-23 Thread =?ISO-8859-1?Q?Hans-J=FCrgen_Sch=F6nig?=
We have toyed around with PostgreSQL's WAL structure and we are wondering whether it is (theoretically) possible to replay WAL records coming from a remote host while a system is working in read only mode. The idea: We are looking for a way to implement a synchronous single-master / multiple sl