On Tuesday 18 October 2005 08:45, Paul Rogers wrote:
> What options are available to interface Slonik? At the moment we're
> using triggers so we can use anything that will produce and execute
> SQL statements. The triggers also work inside a transaction block and
> can be rolled back. Is it possible to examine the result of the
> attempted schema change and undo the result?

For most operations Slonik just calls functions stored within the _cluster 
namespace.  In the case of execute script it calls ddlscript 
( http://www.dbitech.ca/slony/book/function.ddlscript-integer-text-integer.html ). 
Your internal business logic could push DDL commands through this 
automaticly, therefor bypassing an system()/exec() call to slonik.  Nothing 
is replicated to the subscriber nodes untill they are first committed on the 
origin node, and once commited, they can't be rolled back (short of a DDL in 
reverse that will undo what was done).


>
> On Oct 18, 2005, at 11:35 AM, Darcy Buskermolen wrote:
> > On Tuesday 18 October 2005 07:04, progers at technologyimaging.com wrote:
> >> Title: Replicate schema changes
> >> Bug Type: Feature request
> >> Severity: Serious
> >> Software Version: Other
> >> Environment: Debian 3.1, PostgreSQL 8.x
> >> Created By: progers at technologyimaging.com
> >> Description: We are looking for a replication solution that will
> >> replicate
> >> schema changes. More specifically we need to create and drop
> >> sequences
> >> which are unique to certain records. At the moment we are using
> >> triggers to
> >> manage the sequences. So if a query inserts one of these records
> >> it creates
> >> a sequence. If a query deletes the key record then it drops the
> >> appropriate
> >> sequence.
> >>
> >> Slony-I 1.1.0 did not create or drop sequences on the slave as
> >> changes
> >> where made to the master. I'm curious if there is any kind of
> >> workaround or
> >> if this would require a new Slony feature. Status: Submitted
> >>
> >>
> >>
> >> http://gborg.postgresql.org/project/slony1/bugs/bugupdate.php?1447
> >
> > Put all schema chamges through slonik using the execute script
> > command.
> >
> >
> >
> > --
> > Darcy Buskermolen
> > Wavefire Technologies Corp.
> >
> > http://www.wavefire.com
> > ph: 250.717.0200
> > fx: 250.763.1759

-- 
Darcy Buskermolen
Wavefire Technologies Corp.

http://www.wavefire.com
ph: 250.717.0200
fx: 250.763.1759