On Wed, Apr 11, 2018 at 2:34 AM, Chapman Flack <c...@anastigmatix.net> wrote: > On 04/10/2018 04:03 PM, Robert Haas wrote: > >> I suspect you want, or maybe need, to use the same snapshot as the >> scan that retrieved the tuple containing the toasted datum. > > I'm sure it's worth more than that, but I don't know if it's > implementable. > > If I'm a function, and the datum came to me as a parameter, I may > have no way to determine what snapshot the enclosing query used to > obtain the thing passed to me. >
Before query execution, we push the active snapshot, so any time during execution, if you get the active snapshot via GetActiveSnapshot(), you can access it. So, I think during a function execution, if you use GetActiveSnapshot, you should get the snapshot used by enclosing query. -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com
