Re: Most efficient way for libPQ .. PGresult serialization - Mailing list pgsql-hackers

From Joshua Bay
Subject Re: Most efficient way for libPQ .. PGresult serialization
Date
Msg-id CABb-U3anP61O_9megDVCu0xqB51OvOA-v5ivkjdUJDi+XMwF0A@mail.gmail.com
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In response to Re: Most efficient way for libPQ .. PGresult serialization  (Craig Ringer <craig@2ndquadrant.com>)
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Oh I see.
I just read more on use cases PgBouncer, but seems like it can't be used for my project.
The reason is that I need to have my middleware to have full control over each transaction. 
That is it must be able to decide if it's going to commit or abort a single query (reason why libpq is used in the middleware), and it must be able to decide when to send back the result. Also it does things like load balancing with it's algorithm. 

So, what middleware does is (simplied, ignoring other details)
1. listens to query and does load balancing
2. execute query on behalf of client to server with libpq (does not have to be libpq). 
3. serialize the result and send it back 

And the #3 is why I asked for ways to serialize PGresult (of libpq)

Client app will deserialize the result and thus be able to interpret PGresult as if it used libpq itself.

Thanks!

On Thu, Aug 18, 2016 at 9:05 PM, Craig Ringer <craig@2ndquadrant.com> wrote:

On 19 August 2016 at 03:08, Joshua Bay <joshuabay93@gmail.com> wrote:
Thanks,
But I don't think my question was clear enough. 

I already managed the connection pooling, and what I need is to serialize the result.

If PGresult was a contiguous block, I could have just create buffer and call memcpy for serialization, but structure of result seems much more complicated. 

So, I was asking if there is an easy way to achieve serialization

It's wire format is a serialization. That's kind of the point.

I don't understand what you're trying to do here, so it's hard to give a better answer. 

--
 Craig Ringer                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services

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