From: Tom Lane <tgl@sss.pgh.pa.us>
To: Ron Johnson <ronljohnsonjr@gmail.com>
cc: pgsql-general <pgsql-general@postgresql.org>
Subject: Re: PG 14 pg_basebackup accepts --compress=server-zst option
In-reply-to: <CANzqJaAAJmAhgbYYx1T-+-A_myAEOLgDbzE3m5zfOQMwNzcCQQ@mail.gmail.com>
References: <CANzqJaB=-AUnoXh+V6ayLPbRut7yNt7utL-=0+OK4hdh35-cTQ@mail.gmail.com> <CAAPsdhfQ0GvDuNeMZpe_sccHcM=7dHZq=C6wXbM8zFr_X2FD3g@mail.gmail.com> <CAKFQuwYhAbOwvMfCSWg4VMAWDUX1kCZAdG1XQMKnWWFZYyOpTA@mail.gmail.com> <CANzqJaAAJmAhgbYYx1T-+-A_myAEOLgDbzE3m5zfOQMwNzcCQQ@mail.gmail.com>
Comments: In-reply-to Ron Johnson <ronljohnsonjr@gmail.com>
	message dated "Fri, 07 Jun 2024 08:04:33 -0400"
MIME-Version: 1.0
Content-Type: text/plain; charset="UTF-8"
Content-ID: <1251341.1717774388.1@sss.pgh.pa.us>
Content-Transfer-Encoding: 8bit
Date: Fri, 07 Jun 2024 11:33:08 -0400
Message-ID: <1251342.1717774388@sss.pgh.pa.us>
Archived-At: <https://www.postgresql.org/message-id/1251342.1717774388%40sss.pgh.pa.us>
Precedence: bulk

Ron Johnson <ronljohnsonjr@gmail.com> writes:
> On Fri, Jun 7, 2024 at 12:32 AM David G. Johnston <
> david.g.johnston@gmail.com> wrote:
>> I don’t see us adding an error message at this point.

> Me neither.  It just seemed odd.

v14 thinks the argument of --compress must be an integer, and doesn't
really bother with any syntax error checks:

            case 'Z':
                compresslevel = atoi(optarg);
                if (compresslevel < 0 || compresslevel > 9)
                {
                    pg_log_error("invalid compression level \"%s\"", optarg);
                    exit(1);
                }
                break;

In your example, atoi() will return zero and it will sail along with
no compression.  Releases 15 and up have more complex ideas of what
--compress can specify, and seem to syntax-check it much more
thoroughly.

This is a pretty common coding pattern, so I can't get excited
about changing it, especially not in long-stable branches.

			regards, tom lane