On Fri, 21 May 2010, Gurjeet Singh wrote:

> This is exactly the kind of Slony black magic I want to understand. Do we
> have someplace where we can get these internals of Slony, or design specs;
> or would you suggest diving into code?

The original design document is available 
http://developer.postgresql.org/%7Ewieck/slony1/Slony-I-concept.pdf though 
some of the information does seem dated in it and might not reflect the 
current reality.

It is worth your time to give the admin guide a good reading though it isn't 
going to explain everything you want in a clear manner.

I often find myself tracing through the slony code (particularly 
remote_worker.c, slonik.c and the slony1_funcs.sql) to figure out  how 
something actually works.   I sometimes find the best way for me to confirm 
that I understand something is to try and describe it, so I've published a 
blog post on how subscribe set works 
(http://scanningpages.wordpress.com/2010/05/22/slony-subscribe-set-explained/) 
I plan on doing this for a few more slony concepts as I get around to it.

You should also feel free to ask questions on the list about how something 
works.  There is a desire to increase the number of people familiar with 
slony internals (and ideally increase the number of developers contributing 
to slony).  Questions asking how things work internally in slony will 
probably be replied to (though it might take a few days depending on who has 
the ability to reply)


Steve



>
> Regards,
> -- 
> gurjeet.singh
> @ EnterpriseDB - The Enterprise Postgres Company
> http://www.enterprisedb.com
>
> singh.gurjeet@{ gmail | yahoo }.com
> Twitter/Skype: singh_gurjeet
>
> Mail sent from my BlackLaptop device
>