MySQL Connections

Hi,

I am using MYSQL 5.0 server. I am facing some problem in my application. Please consider following scenario.

I have one application, which is firing 1000 threads and each thread is connecting to the *same* Mysql Database. Once all threads gets connected, each of them is firing a SELECT query at the *same time*. I am calculating the time for each SELECT takes. There are 4 joins in the SELECT query (it is a big join with some lacks of records). I am getting the timings as 6000 Secs or so. I am using MYSQL++ library API's.

Databaes size = 10gb
I have following variables set in /etc/my.cnf

max_allowed_packet=100000000
max_connections=10000
join_buffer_size=5M


My question is
1. Does these timings are realistic?
2. Does MYSQL server supports 1000 connections at-a-time? If yes, Where I can see the limit?
3. Does SELECT have any optimization method so that the timings gets reduced?

Please get back to me ASAP. Also feel free if you need some more information.

Thanks,
-Piyush