Dennis Bjorklund <db@zigo.dhs.org> writes:
> On Thu, 8 Apr 2004, Tom Lane wrote:
>> See my previous point: the index does not actually fail, in our current
>> implementation, because strcoll() is unaffected by the database's
>> encoding setting.
> How can it be? If I have a utf-8 template1 and a table with an index
> sorted according to the utf-8 characters in some locale. Then this table
> and index is copied into a Latin1 database. When I interpret these bytes
> as Latin1 in the index, the ordering does not have to be the same as it
> was before and the index can not be used.
No, the ordering *will* be the same as it was before, because strcoll()
is still functioning the same. You'd get the same answer from a sort
operation since it depends on the same operators.
Now, you will probably complain that the sort order doesn't appear
correct according to your Latin1 interpretation --- and you're right.
But the index is not corrupt, it is still consistent in its own terms.
> I don't understand what you mean when you say that strcoll() is unaffected
> by the database's encoding setting. It interprets characters, how can it
> not be?
It interprets them according to LC_CTYPE, which does not change.
regards, tom lane