> > I suspect the tuple at (0,1) has been the subject of a failed update. >
Yep. > Your problem here is that you're mistaking the t_ctid field of a tuple > header for the tuple's address. It is not that; it's really just garbage > normally, and is only useful to link forward to the next version of the > row from an outdated tuple. I think we do initialize it to the tuple's > own address during an INSERT, but either a completed or failed UPDATE > would change it. > Thanks. That helps clarify the comments in htup_details.h, actually. > I do not think there is any way to get the true address of a heap tuple > out of a composite Datum manufactured from the tuple. Most of the other > system columns can't be gotten from a composite Datum either, because of > the field overlay in HeapTupleHeaderData's union t_choice. Well shoot. That kinda spoils my plans. What about this? Is the tuple currently being evaluated (I suppose in the case of a sequential scan) available in the context of a function call? Thanks again for your time! It's much appreciated. eric
