Re: pgsql: Remove BufFile's isTemp flag.

Hi,

On 2017-11-17 11:23:54 -0500, Tom Lane wrote:
> OK, after looking through the history, the reason for isTemp = false
> is indeed to allow BufFileCreate() to maintain its old semantics,
> wherein you could attach a BufFile to an already-existing, possibly
> non-temp file. There have not been any core callers of BufFileCreate()
> in a long time (maybe not since that commit, in fact), but I imagine
> I left it alone for fear that extensions might be using it. I see though
> that Bruce ifdef'd it out in 20ad43b5, so there aren't any extensions
> using it either.
>
> We should flat-out remove the function, since this change makes it
> impossible to resurrect with its old semantics.

That sounds reasonable.

> I wonder whether we should then rename BufFileCreateTemp to just
> BufFileCreate, since it's no longer possible to have a BufFile that
> isn't temp. I suspect that some attention to the comments might be
> needed too.

Thomas?

> Or maybe we should revert 11e264517. It doesn't seem to be buying
> much to make up for the loss of flexibility.

There's a bunch of work adding new functionality to buffile.c
pending. And having code paths that have been dead for 10+ years around
and maintaining them in working order doesn't seem like a good use of
time.

Greetings,

Andres Freund