Re: [HACKERS] Safe/Fast I/O ...

>> When doing a sequential scan on a table, the OS is doing a one-page
>> prefetch, which is probably enough.  The problem is index scans of the
>> table.  Those are not sequential in the main heap table (unless it is
>> clustered on the index), so a prefetch would help here a lot.
>>
>> That is where we need async i/o.  I am looking in BSDI, and I don't see
>> any way to do async i/o.  The only way I can think of doing it is via
>> threads.
>
>
>     O_ASYNC      Enable the SIGIO signal to be sent to the process group when
>                  I/O is possible, e.g., upon availability of data to be read.
>
>Now I am questioning this.  I am not sure this acually for file i/o, or
>only tty i/o.
>

async file calls:
    aio_cancel
    aio_error
    aio_read
    aio_return -- gets status of pending io call
    aio_suspend
    aio_write

And yes the Gray book is great!

Jordan Henderson