On 07.03.2011 17:43, Tom Lane wrote:
> because two expressions that are equal() must necessarily have the same collation
> property.
Peter, Tom,
I am not able to see this.
If 'abc' == 'abc' is not collation depending at all. It is only
encoding depending.
Collation is only needed for upper(), lower() and sorting.
Means it tells if e.g. upper('i') will get Y or I.
It tells if the German s-umlaut will be sorted together with 's' or
after 'z'.
Btw. the follows on implementing collations will be different -
and I hope Peter is aware of it.
My experience is that a huge follow will be that users will complain
that the
sorting isn't correct even when it is correct.
Susanne
--
Susanne Ebrecht - 2ndQuadrant
PostgreSQL Development, 24x7 Support, Training and Services
www.2ndQuadrant.com