Re: PostgreSQL, Asynchronous I/O, Buffered I/O and why did fsync-gate not affect Oracle or MySQL?

[Ron <ronljohnsonjr@xxxxxxxxx>]

    On 5/2/21 8:46 AM, Pól Ua Laoínecháin wrote:
    [snip]
> Now, I'm not quite sure that I completely comprehend matters: Is there
> a difference between Asynchronous I/O and Buffered I/O?
>     
    
    * Asynchronous (a-syn-chron-ous) is an adjective which means "not
    together with time".
    * Buffered means "read more than you need at the moment, and then do
    processing to/from a cache".
    
    They are not mutually exclusive.
    
    Their antonyms are
    * Synchronous (syn-chron-ous): together with time.
    * Direct, where you read/write only what you need at the moment,
    directly to/from the IO device.
    
    Thus, async IO is where you tell the IO subsystem that you
    need something, and then go off and do something else; the
    IO system interrupts you when the data has been delivered.
    Synchronous IO is where you request IO and then wait for
      the data.

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