On 4/11/18 17:08, Peter Geoghegan wrote: >> However, I don't see any point in defining collations here, because >> INCLUDE attributes exist solely for index-only scans. So, index just >> can return value of INCLUDE attribute "as is", no point to do something >> with collation. >> >> So, I propose to disable collations for INCLUDE attributes. > Hmm. I'm not sure that that's exactly the right thing to do. We seem > to want to have case-insensitive collations in the future. The fact > that you can spell out collation name in ON CONFLICT's unique index > inference specification suggests this, for example. I think that a > collation is theoretically allowed to affect the behavior of equality, > even though so far we've never tried to make that work for any > collatable datatype.
But in this case it doesn't even do equality comparison, it just returns the value. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services