> Note in particular that index scans cannot return the same index tuple twice - > - processing a page at a time ensures that that cannot happen. > > Can a loose index scan return the same tuple (i.e. a tuple with the same heap > TID) to the executor more than once? >
The loose index scan shouldn't return a tuple twice. It should only be able to skip 'further', so that shouldn't be a problem. Out of curiosity, why can't index scans return the same tuple twice? Is there something in the executor that isn't able to handle this? -Floris
