Re: Prototype: In-place upgrade v02

Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
> The bpchar_pattern_ops change you mentioned must be this one:
>> A not-immediately-obvious incompatibility is that the sort order within
>> bpchar_pattern_ops indexes changes --- it had been identical to plain
>> strcmp, but is now trailing-blank-insensitive.  This will impact
>> in-place upgrades, if those ever happen.

Yup.

> The way I read that, bpchar_pattern_ops just became less sensitive. Some 
> values are now considered equal that weren't before, and thus can now be 
> stored in any order. That's not an incompatible change, right?

No, consider 'abc^I' vs 'abc ' (^I denoting a tab character).  These are
unequal in either case, but the sort order has flipped.
        regards, tom lane