Re: [PATCH] Add SIGCHLD catch to psql

Stephen Frost wrote:
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> Greetings,
> 
>   Toying around with FETCH_COUNT today, I discovered that it didn't do
>   the #1 thing I really wanted to use it for- query large tables without
>   having to worry about LIMIT to see the first couple hundred records.
>   The reason is simple- psql ignores $PAGER exiting, which means that it
>   will happily continue pulling down the entire large table long after
>   you've stopped caring, which means you still have to wait forever.
> 
>   The attached, admittedly quick hack, fixes this by having psql catch
>   SIGCHLD's using handle_sigint.  I've tested this and it doesn't
>   appear to obviously break other cases where we have children (\!, for
>   example), since we're not going to be running a database query when
>   we're doing those, and if we are, and the child dies, we probably want
>   to *stop* anyway, similar to the $PAGER issue.
> 
>   Another approach that I considered was fixing various things to deal
>   cleanly with write's failing to $PAGER (I presume the writes *were*
>   failing, since less was in a defunct state, but I didn't actually
>   test).  This solution was simpler, faster to code and check, and alot
>   less invasive (or so it seemed to me at the time).
> 
>   Anyway, this makes FETCH_COUNT alot more useful, and, in my view, the
>   current behaviour of completely ignoring $PAGER exiting is a bug.

Plesae add this to the next commit-fest:
https://commitfest.postgresql.org/action/commitfest_view/inprogress

Thanks.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com