Re: Need help for our thesis. - Mailing list pgsql-hackers

As luck would have I've put some thought into this problem before as 
well.  Having reviewed the code quite a bit, and played around with the 
backend, my intuition tells me that the following would work.

Write a custom "cluster-aware" postmaster so it distributes queries to 
various machines.  Of course each machine would have to be running a 
normal postmaster to receive the queries.  And, the cluster-aware 
postmaster would need to be informed of which machines to submit 
queries to (e.g. listed in a configuration file).  Queries could be 
processed in the following ways:
* database management queries (e.g. create database, create 
table, alter table, etc. . . ) would be distributed to every machine* select queries would be distributed to every
machine. The 
 
cluster-aware postmaster would merge the results before delivering them 
to the client.* an insert query would go to one machine only, and the 
cluster-aware postmaster could switch between the designated machines 
after each insert.  For example, given two machines, the first insert 
would go to machine A, the second to machine B, etc . . .

Don't know if that's been tried, but that's where I would start.  
Postgres' modular design of a postmaster and a backend would make this 
relatively easy to do, because the only thing you might end up writing 
is the one cluster-aware postmaster.  If you end up doing this let me 
know and if I have time I'll help out with the design/coding.

Richard Schilling
Lake Stevens, WA USA



On 2003.07.04 18:56 MIka Santos wrote:
> Gud day! We are currently having our thesis for our undergarduate
> course and this involoves the code of PostgreSQL. Basically, our
> thesis needs a modification of the existing code of the said database.
> As of now, our University has an existing online registration system
> which uses Postgre as their back end. But the problem is the existing
> one is not a distributed system. Our thesis adviser would like us to
> deal with the load balancing of the said online registration. He
> wanted a multidatabase querying. For example, we knew that the
> following statements are posible,
>                    select *
>                    from t1, t2., t3;
> provided that t1 and t2, t3 are tables from a single database.
> Our thesis is to make the following satatement legal
>                   select *
>                   from d1, d2, d3;
> provided that d1 and d2, d3 are separate databases.
> We are currently having our research about this problem and as
> beginners, we surely need help from experts like you. Any form of
> comments and suggestions will surely be appreciated by the group.
>       Thank you very much and hope to here from you.
> 
> 
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