Tom Lane wrote:
>
> It occurs to me that we also need a better term for the overall concept.
> "cacheability" has misled at least two people (that I can recall) into
> thinking that we maintain some kind of function result cache --- which
> is not true, and if it were true we'd need the term "cacheable" for
> control parameters for the cache, which this categorization is not.
>
> I am thinking that "mutability" might be a good starting point instead
> of "cacheability". This leads immediately to what seems like a fairly
> reasonable set of names:
>
> pg_proc column: promutable or proismutable
>
> case 1: "immutable"
> case 2: "mutable", or perhaps "stable"
> case 3: "volatile"
I like 1 and 3 :-)
I think 2 should be something like "stable." Mutable and volitile have very
similar meanings.
I'm not sure, the word stable is right, though. Cacheable has the best meaning,
but implies something that isn't. How about "persistent" or "fixed?"