hi.
index_create comments:
/*
* Btree text_pattern_ops uses text_eq as the equality operator, which is
* fine as long as the collation is deterministic; text_eq then reduces to
* bitwise equality and so it is semantically compatible with the other
* operators and functions in that opclass. But with a nondeterministic
* collation, text_eq could yield results that are incompatible with the
* actual behavior of the index (which is determined by the opclass's
* comparison function). We prevent such problems by refusing creation of
* an index with that opclass and a nondeterministic collation.
*
* The same applies to varchar_pattern_ops and bpchar_pattern_ops. If we
* find more cases, we might decide to create a real mechanism for marking
* opclasses as incompatible with nondeterminism; but for now, this small
* hack suffices.
*
* Another solution is to use a special operator, not text_eq, as the
* equality opclass member; but that is undesirable because it would
* prevent index usage in many queries that work fine today.
*/
here, "text_eq" should be "texteq"?
