=?ISO-8859-2?Q?pasman_pasma=F1ski?= <pasman.p@xxxxxxxxx> writes: > I found second use case. Look at expression: > where left(str,n)='value' > function left(str,n) increase monotonically for str and n. With this > feature it can use index on str. Can't get excited about that, because that only works in C locale, and in C locale you can already get the same result with WHERE str LIKE '...%' Also, I think you just moved the goalposts quite a bit by introducing multiple-argument functions into the proposed feature. That's going to add even more complexity, for instance there would need to be a way to specify which argument(s) the function was monotonic in. The C versus not-C locale aspect also shows that for textual arguments, it might matter which locale you're talking about. In short, this is looking awfully complicated, and I gauge the probable level of interest by the fact that you're the first person to ask for it in more than a dozen years of Postgres development. regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
