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