Thread: BUG #18829: RAISE NOTICE appends 's' to string in PostgreSQL 17.2

The following bug has been logged on the website:

Bug reference:      18829
Logged by:          Armand
Email address:      armandnortjee@gmail.com
PostgreSQL version: 17.2
Operating system:   Windows 10
Description:

In PostgreSQL 17.2, when using the RAISE NOTICE command with a string
variable, the output incorrectly appends an extra 's' to the string value.
This issue does not occur when running the same code in earlier PostgreSQL
versions (e.g., PostgreSQL 16).

DO $$
DECLARE
    my_var TEXT := 'garth';
BEGIN
    RAISE NOTICE '%s is slim', my_var;
END
$$;

Expected Result:
The output should be:
NOTICE:  garth is slim

Actual Result:
The output incorrectly shows:
NOTICE:  garths is slim

PG Bug reporting form <noreply@postgresql.org> writes:
> In PostgreSQL 17.2, when using the RAISE NOTICE command with a string
> variable, the output incorrectly appends an extra 's' to the string value.

The substitution marker in plpgsql RAISE strings is just "%", not
"%s" as it is in C, so this output is expected.  That wasn't the best
design perhaps, but it's impossible to change it now.

> This issue does not occur when running the same code in earlier PostgreSQL
> versions (e.g., PostgreSQL 16).

You are quite mistaken about that.  It's been like this since the
beginning of plpgsql.

            regards, tom lane

The following bug has been logged on the website:

Bug reference:      18829
Logged by:          Armand
Email address:      armandnortjee@gmail.com
PostgreSQL version: 17.2
Operating system:   Windows 10
Description:        

In PostgreSQL 17.2, when using the RAISE NOTICE command with a string
variable, the output incorrectly appends an extra 's' to the string value.
This issue does not occur when running the same code in earlier PostgreSQL
versions (e.g., PostgreSQL 16).

DO $$
DECLARE    my_var TEXT := 'garth';
BEGIN    RAISE NOTICE '%s is slim', my_var;
END
$$;

Expected Result:
The output should be:
NOTICE:  garth is slim

Actual Result:
The output incorrectly shows:
NOTICE:  garths is slim

This is not a bug, it's working as documented.

The 's' is there because you told it to be there. The docs say: "Inside the format string, % is replaced by the string representation of the next optional argument's value."

This is not a printf style format string, as you appear to think it is.

cheers

andrew

--
Andrew Dunstan
EDB: https://www.enterprisedb.com

On Sun, Mar 2, 2025 at 11:09 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> PG Bug reporting form <noreply@postgresql.org> writes:
> > In PostgreSQL 17.2, when using the RAISE NOTICE command with a string
> > variable, the output incorrectly appends an extra 's' to the string value.
>
> The substitution marker in plpgsql RAISE strings is just "%", not
> "%s" as it is in C, so this output is expected.  That wasn't the best
> design perhaps, but it's impossible to change it now.
>
> > This issue does not occur when running the same code in earlier PostgreSQL
> > versions (e.g., PostgreSQL 16).
>
> You are quite mistaken about that.  It's been like this since the
> beginning of plpgsql.
>

While Tom is certainly right about this, I have seen the following
plpgsql code style which looks like the behavior the OP is suggesting,
so they could be mis-remembering.

pagila=# DO $$
DECLARE
    my_var TEXT := 'garth';
BEGIN
    RAISE NOTICE USING message = format('%s is slim', my_var);
END
$$;
NOTICE:  garth is slim
DO


Robert Treat
https://xzilla.net