Horton

Re: Bug in documentation: https://www.postgresql.org/docs/current/spi-examples.html

David G. Johnston <david.g.johnston@gmail.com>

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From: "David G. Johnston" <david.g.johnston@gmail.com>
To: Curt Kolovson <ckolovson@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, pgsql-docs@lists.postgresql.org
Date: 2023-07-18T03:13:41Z
Lists: pgsql-docs 
On Mon, Jul 17, 2023 at 7:45 PM Curt Kolovson <ckolovson@gmail.com> wrote:

> I’d vote for showing both (with RETURNING and without), since without it
> the second argument to SPI_exec has no effect in this example, which may
> not be obvious. That seems to be one of the subtle points illustrated by
> this example.
>

I concur:

=> SELECT execq('CREATE TABLE a (x integer)', 0); // start at 0
=> INSERT INTO a VALUES (execq('INSERT INTO a VALUES (0)', 0)); // insert 2
=> SELECT execq('SELECT * FROM a', 0);

+ => SELECT execq('INSERT INTO a SELECT x + 2 FROM a returning x', 1); --
one more
+ -- (IIUC non-deterministically regardless of observed behavior even if
there were a limit in the SELECT)

=> SELECT execq('INSERT INTO a SELECT x + 2 FROM a', 1); // three more
=> SELECT execq('SELECT * FROM a', 10); // 6 as 10 is a limit

...[next block]
David J.

Commits

  1. Doc: fix out-of-date example of SPI usage.

  2. Fix SPI documentation for new handling of ExecutorRun's count parameter.