Re: psql: Count all table footer lines in pager setup

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>

To: Erik Wienhold <ewie@ewie.name>

Cc: Greg Sabino Mullane <htamfids@gmail.com>, pgsql-hackers@postgresql.org

Date: 2025-10-02T21:00:30Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Improve psql's ability to select pager mode accurately.
- 27da1a796ff9 19 (unreleased) landed

Attachments

v4-0001-Improve-psql-s-ability-to-select-pager-mode-accur.patch (text/x-diff) patch v4-0001
v4-0002-Make-some-minor-performance-improvements-in-psql-.patch (text/x-diff) patch v4-0002
v4-0003-Add-a-TAP-test-to-exercise-psql-s-use-of-PAGER.patch (text/x-diff) patch v4-0003

Erik Wienhold <ewie@ewie.name> writes:
> On 2025-10-02 00:25 +0200, Tom Lane wrote:
>> I am not entirely sure that we should commit 0002 though; it may be
>> that the savings is down in the noise anyway once you consider all the
>> other work that happens while printing a big table.  A positive reason
>> not to take it is something I realized while checking test coverage:
>> we never execute any of the maybe-use-the-pager branch of PageOutput
>> in the regression tests, because isatty(stdout) will always fail.

I realized that we could address that if we really wanted to,
using the same infrastructure as for tab-completion testing.
0001 and 0002 attached are the same as before, and then I added
0003 which adds a draft-quality TAP test.  Code coverage checks
show that this adds only about 10 more lines of coverage in
psql proper, but in print.c most of the pager-related logic is
now covered.

			regards, tom lane