Yes, i wrote this for pleasure and discusion, not for solve a real problem :). 2011/9/25, Tom Lane <tgl@xxxxxxxxxxxxx>: > =?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 > -- ------------ pasman -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
