On Tue, Mar 28, 2017 at 10:31 PM, Pavan Deolasee <pavan.deola...@gmail.com> wrote: > > On Tue, Mar 28, 2017 at 4:05 PM, Amit Kapila <amit.kapil...@gmail.com> > wrote: >> >> As asked previously, can you explain me on what basis are you >> considering it robust? The comments on top of datumIsEqual() clearly >> indicates the danger of using it for toasted values (Also, it will >> probably not give the answer you want if either datum has been >> "toasted".). > > > Hmm. I don' see why the new code in recheck is unsafe. The index values > themselves can't be toasted (IIUC), but they can be compressed. > index_form_tuple() already untoasts any toasted heap attributes and > compresses them if needed. So once we pass heap values via > index_form_tuple() we should have exactly the same index values as they were > inserted. Or am I missing something obvious here? >
I don't think relying on datum comparison for compressed values from heap and index is safe (even after you try to form index tuple from heap value again during recheck) and I have mentioned one of the hazards of doing so upthread. Do you see any place else where we rely on comparison of compressed values? -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
