Re: [PATCH} Move instrumentation structs

On 2026-Jan-13, David Rowley wrote:

> There's a bit of conflicting opinion going on here with the changes
> made in 128897b101e0.
>
> "false when it's value for in-memory space"
>
> I think the differing opinions depend on what you fill in the missing
> words with in the badly written English. If you read "value" as "the
> value", then "it's" is correct. Whereas if you read it as "value is",
> then "its" is correct. I assume you didn't read it the same way as
> John did.

Yeah, if the "is" had been there I wouldn't have made the change. I
mean, this would have been correct:

true when maxSpace is value for on-disk
space, false when its value is for in-memory space

I debated whether to add the "is" or change the "its" to "it's" and
decided that the smaller change was better. But I agree that a bigger
rewording may be a better solution.

> + bool isMaxSpaceDisk; /* true when the maxSpace value tracking is
> + * on-disk space, false means it's tracking
> + * memory space */

Sounds about right, though I think we can shave some words off that.
How about

int64 maxSpace; /* maximum amount of space occupied among sort
* of groups, either in-memory or on-disk */
bool isMaxSpaceDisk; /* true when maxSpace tracks on-disk space, false
* means in-memory */
?

(CCed Jacob as author and John as committer of that change, in case they
care to comment.)

FWIW the original wording comes from d2d8a229bc58.

Incidentally, I notice that tuplesort_updatemax() has this comment:

/*
* Note: it might seem we should provide both memory and disk usage for a
* disk-based sort. However, the current code doesn't track memory space
* accurately once we have begun to return tuples to the caller (since we
* don't account for pfree's the caller is expected to do), so we cannot
* rely on availMem in a disk sort. This does not seem worth the overhead
* to fix. Is it worth creating an API for the memory context code to
* tell us how much is actually used in sortcontext?
*/

... and I think we already have the API that this comment hypothesizes
about.

--
Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/
"La virtud es el justo medio entre dos defectos" (Aristóteles)