Sorry for delay. I didn't noticed because it was a private email. > "Well protocol handling of simple query(regular SQL) and prepared query > is totally different. Simple query protocol is simple: just send a > query and receive the result. The protocol used for prepared query > (called "extended query protocol") is much more complex: it has > several phases: parse, bind, execute. I suggest you carefully read > "Frontend/Backend Protocol" section of PostgreSQL document. However I > can think of anything which makes your idea impossible at this point." > > I just wanted to note that I have started working on this idea. Work is very > slow at the moment, but I am getting a grasp of what should be done. > > I would like to ask for little help about debugging the frontend/backend > protocol. I am using raw buffer and pool_send_and_wait() at the moment for > constructing the extended protocol messages. I am getting errors like > insufficient data left in message and invalid message format. So my messages > aren't in proper format, but I am having hard time to see what went wrong. I > guess the best way to debug this is to add elog(DEBUG1) messages to the libpq > backend, and see what the data looks like in there?
Another idea is tweaking pool_write() so that it displays what data it is sending. > Libpq is looking really attractive, but I guess using it directly is out of > the question. However, I wonder if it would be wise to port a part of it to > pgpool-II, that is the nice handling of message construction and reading in > src/interfaces/libpq/fe-misc.c? The file is a bit over 1200 lines, but not > all of it is needed. The other choice is to write the needed functions to > write parse/bind/execute messages. I don't think fe-misc.c is usefull for you becauae it just handles very low level of protoocl, which is totally different from pgpool-II's architecture. Probably you should look into fe-exec.c how to construct extended protocol messages. -- Tatsuo Ishii SRA OSS, Inc. Japan English: http://www.sraoss.co.jp/index_en.php Japanese: http://www.sraoss.co.jp _______________________________________________ Pgpool-hackers mailing list [email protected] http://pgfoundry.org/mailman/listinfo/pgpool-hackers
