I wrote: > Maybe. I think where KaiGai-san is trying to go with this is being > able to turn an ExpandedObject (which could contain very large amounts > of data) directly into a toast pointer or vice versa. There's nothing > really preventing a TOAST OID from having more than 1GB of data > attached, and if you had a side channel like this you could transfer > the data without ever having to form a larger-than-1GB tuple.
BTW, you could certainly imagine attaching such infrastructure for direct-to-TOAST-table I/O to ExpandedObjects today, independently of any ambitions about larger-than-1GB values. I'm not entirely sure how often it would get exercised, which is the key subtext of what I wrote before, but it's clearly a possible optimization of what we do now. regards, tom lane -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers