On 16/01/2023 12:23, Peter Eisentraut wrote:
On 21.11.22 10:29, Peter Eisentraut wrote:
On 21.11.22 00:57, Heikki Linnakangas wrote:
On 19/11/2022 13:00, Peter Eisentraut wrote:
AFAICT, this thread updated the API of LogicalTapeSetCreate() in PG15,
but did not adequately update the function header comment. The comment
still mentions the "shared" argument, which has been removed. There is
a new "preallocate" argument that is not mentioned at all. Also, it's
not easy to match the actual callers to the call variants described in
the comment. Could someone who remembers this work perhaps look this
over and update the comment?
Is the attached more readable?
That looks better, thanks.
I'm not 100% sure of the "preallocate" argument. If I understand
correctly, you should pass true if you are writing multiple tapes at
the same time, and false otherwise. HashAgg passed true, tuplesort
passes false. However, it's not clear to me why we couldn't just
always do the preallocation. It seems pretty harmless even if it's not
helpful. Or do it when there are multiple writer tapes, and not
otherwise. The parameter was added in commit 0758964963 so presumably
there was a reason, but at a quick glance at the thread that led to
that commit, I couldn't see what it was.
Right, these are the kinds of questions such a comment ought to answer.
Let's see if anyone chimes in here, otherwise let's complain in the
original thread, since it had nothing to do with this one.
So nothing has happened. Let's get your changes about the removed
"shared" argument committed, and we can figure out the "preallocated"
thing separately.
Ok, pushed. I included the brief comment on "preallocated", but it would
be nice to improve it further, per the above discussion.
Thanks!
- Heikki
