added index ordering (ASC/ DESC)

[museghost]

In postgresql, if an index has ASC or DESC, the original engine could not handle it.
It is because of the returned column of the index.

For example, the index name "foo_index" and its columns are foo1 and its ordering is DESC.
i.e. foo_index has "foo DESC"

With the above sample, the returned column name is "foo DESC", not "foo" only.

This workround could handle the postfix "DESC or ASC", and normal column as well.