The Last Optimization

I have a huge table with 14 field and few million of data...
My application Php/Pg start to be impossible to use.

    Redhat 7.3
    Dual PIII 900Mhz System
    2GB RAM

I did already a some optimization optimization :

    max_connections = 64
    shared_buffers = 32000
    sort_mem = 64336
    fsync = false
                        ---
    echo 128000000 > /proc/sys/kernel/shmmax

    also Vaccum,analyze and Index

                        ---

    This optimization was enough at the beginning but NOT now with some
million of instance.

    So WHAT I CAN DO ??? USE ORACLE ???

    I Think maybe to split my mean table to different table Mean_a Mean_b
... Mean_z ???
    IF it's the way someone where I can find doc or help about howto split
table ???

    I M lost !!! ;)



Areski