[ADMIN] how to improve performance in libpq?

[Tony Liao]

Hi,All,
     I have a question in libpq.the postgresql dadabase about 32MB(base on
backup),and I tried to analyze query as :EXPLAIN ANALYZE SELECT
.........where id=123 ,got the total actual time is 2.882ms.
     Now,I start a test programe base on ../src/test/examples/testlibpq.c
,which has 900 connection pools,and the id will be to increase for each
query.In total I test 160000 queries, used time 1012s. That seems a greate
different with 2.88ms/each query.    any idea?
     test environment      :
     database hardware    CUP  2*Xeon 5405
                                    MEMORY  DDR2 16GB/800 with DIMM
                                    HARDISK   160GB/8M SATA
      network :LAN 1Gbps


      configuration files:
         max_connections = 3000
         shared_buffers = 64MB
         work_mem = 4MB
         maintenance_work_mem = 4MB
         max_stack_depth = 1MB
         the others as default.

        any idea?
        I hope you can understand,thanks.