Bryn Llewellyn <bryn@xxxxxxxxxxxx> writes: > OK, so I'm obliged to answer. > Because SQL rests on the principle that you just say *what* you want but > not *how*. It also rests on the principle that the programmer shouldn't be too concerned about micro-efficiencies. You've given a perfectly good six-line implementation of what you want; use it and be happy. > Oracle Database 12c Release 2 (and later) has a validate_conversion() built-in. [ shrug... ] We are not Oracle. One of the main ways in which we are not Oracle is that we support extensible database functionality. To write a "validate_conversion" function that supports extension datatypes, but doesn't use something morally equivalent to a subtransaction, would be a nightmare: large, fragile, and probably not all that much faster. regards, tom lane
