On 2022-08-16 14:42:48 -0700, Bryn Llewellyn wrote:
> hjp-pgsql@hjp.at wrote:
> The OP wants some kind of progress indicator. To be useful, such
> an indicator should be approximately linear in time. I.e. if your
[...]
>
>
> I see, Peter. You’d read the OP’s mind.
Not much mind-reading involved, I hope. The first sentence in the
message was:
| I like to have what I call “baby sitting” messages such as “Completed 15 out of 1023”.
That's what I would call a "progress indicator". Such things were
already common when I first got involved with computers almost 40 years
ago, so there isn't much to guess or to invent.
> But I’d failed to. I saw the subject, you I assumed that the OP wanted
> the entire result set together with the count of the results. (After
> all, there’s no inflexions of “page” in the OP’s question.)
I don't think his question was about paging. That's a different although
related topic.
> It sounds like the OP wants a fast approximate count for a query whose
> restriction isn’t known until runtime.
Maybe an approximate count would be enough, but he didn't say so.
(He did later clarify that he's fetching a lot of data for each row, so
«select count(*) ,,,» is indeed much faster than «select * ...» due to
the sheer amount of data to be transferred. That wasn't obvious from his
first message, but I hedged against the possibility in my answer.)
hp
--
_ | Peter J. Holzer | Story must make more sense than reality.
|_|_) | |
| | | hjp@hjp.at | -- Charles Stross, "Creative writing
__/ | http://www.hjp.at/ | challenge!"