On Mon, Mar 15, 2010 at 10:53 AM, Tom Lane <tgl@xxxxxxxxxxxxx> wrote:
That makes sense.
Greg Smith <greg@xxxxxxxxxxxxxxx> writes:For an example like this one, you have to keep in mind that the
> VJK wrote:
>> Since Pg does not use the concept of rollback segments, it is unclear
>> why deletion produces so much disk IO (4GB).
toast-table rows for the large bytea value have to be marked deleted,
too. Also, since I/O happens in units of pages, the I/O volume to
delete a tuple is just as much as the I/O to create it.
That makes sense.
regards, tom lane
