Re: retrieve rows in a specified order

Paul <paul_at_not.a.chance.ie> schrieb:
>> 2) Adding implicit ordering information would give you nothing
>> that you don't already have with explicit ordering. Except implicit
>> ordering would require a bunch of new operations, like the aforementioned
>> MOVE UP, MOVE DOWN, etc. That is, it would add complexity but
>> no power.
>
> Maybe I'm wrong here, but have you mixed up "implicit" and "explicit" in
> this paragraph?
>
> Adding *_explicit_* (i.e. by row) ordering would give you nothing that
> you don't already have with *_implicit_* (i.e. by key or given field
> name) ordering. Except *_explicit_* (row) ordering would require a bunch
> of new operations...

How is "by key or given field name" implicit? Implicit means implied though not directly expressed, so if you directly express a given field name, that's not implicit.

RDBMSes have explicit ordering, in that if you want a particular order, you must explicitly specify it. Implicit ordering would be if each row implicitly had an ordering field tacked on which was implicitly used in queries where no ordering was given. And it would probably require some new operations to modify this implicit ordering. Received on Sat Jan 03 2004 - 21:39:57 CET