On 10/31/2016 05:15 PM, Samuel Williams wrote: > Daniel, your reply is awesome :) I love the historical context and it > brings much clarity to the discussion! > > It's now understandable why the commands were named the way they were. > > I'm surprised that distros are making their own commands for > postgres.. isn't that a bit invasive? No, actually it is quite handy: https://wiki.debian.org/PostgreSql It allows you to handle multiple instances of Postgres easily: aklaver@arkansas:~$ lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 14.04.5 LTS Release: 14.04 Codename: trusty aklaver@arkansas:~$ pg_lsclusters Ver Cluster Port Status Owner Data directory Log file 9.3 main 5432 down postgres /var/lib/postgresql/9.3/main /var/log/postgresql/postgresql-9.3-main.log 9.4 main 5434 online postgres /var/lib/postgresql/9.4/main /var/log/postgresql/postgresql-9.4-main.log aklaver@arkansas:~$ sudo pg_ctlcluster 9.3 main start aklaver@arkansas:~$ pg_lsclusters Ver Cluster Port Status Owner Data directory Log file 9.3 main 5432 online postgres /var/lib/postgresql/9.3/main /var/log/postgresql/postgresql-9.3-main.log 9.4 main 5434 online postgres /var/lib/postgresql/9.4/main /var/log/postgresql/postgresql-9.4-main.log > > > > On 1 November 2016 at 06:50, Daniel Verite <daniel@xxxxxxxxxxxxxxxx> wrote: >> Samuel Williams wrote: >> >>> John - that's an interesting example. If it's that easy, why isn't >>> that the approach given in tutorials and other documentation? What was >>> the motivation for the createuser command? >> >> initdb, createdb and createuser existed even before Postgres >> adopted SQL, back when it was developed by the University of >> Berkeley. >> >> You can find references to these commands in the doc here: >> http://db.cs.berkeley.edu/postgres-v4r2/postgres-setup.ps >> which dates back from 1994. >> (fun fact: there was no psql yet, the equivalent command was called >> "monitor". How about that for a name that has seemingly nothing >> to do with postgres? :) >> >> According to these old instructions, commands are installed >> by default into /usr/local/postgres/bin, >> so that was their namespace. They were not supposed to be mixed >> with other non-postgres commands. >> >> That's still the case today if you run ./configure and >> "make install" from the current postgresql sources: >> these commands end up in /usr/local/pgsql/bin >> Some installers such as the EDB installers for Windows or Unix >> typically use a dedicated directory for PostgreSQL, so again its >> commands don't get mixed with other stuff. >> >> As for the Postgresql pre-compiled packages that come with Linux >> distributions, they need to respect the policy of their distros, >> meaning that all user-callable commands should be in the default $PATH. >> That implies that, for instance, postgresql's "createuser" ends up >> in $PATH along with the system's "adduser", even though they have >> hardly anything to do with each other, so yes, that's somehow >> unfortunate. >> But these decisions are made by packagers and distributions, not >> by the PostgreSQL developers. >> >> Some of these commands are already documented as deprecated, >> for example "createlang", which I find in Ubuntu 14.04 /usr/bin: >> $ man createlang >> [...] >> Caution >> createlang is deprecated and may be removed in a future PostgreSQL >> release. Direct use of the CREATE EXTENSION command is recommended >> instead. >> >> The same could theorically be done to createuser/dropuser or >> createdb/dropdb, but there's the question of whether this would create >> more harm that good, because they're much widely used in >> existing scripts and tutorials. >> >> Note that in any case your proposal to use "pg" as an >> umbrella-command wouldn't fly with these systems because pg is a >> pager from the Debian's util-linux package. >> >> $ which pg >> /usr/bin/pg >> >> $ man pg >> PG(1) User Commands >> PG(1) >> >> NAME >> pg - browse pagewise through text files >> >> SYNOPSIS >> pg [-number] [-p string] [-cefnrs] [+line] [+/pattern/] [file...] >> ... >> >> Also, the same Debian/Ubuntu systems don't have initdb or pg_ctl >> in the default $PATH, as these commands are superseded >> by different distro-specific pg_* commands . This is also >> something that should be considered if thinking of unifying >> the binaries. >> >> >> Best regards, >> -- >> Daniel Vérité >> PostgreSQL-powered mailer: http://www.manitou-mail.org >> Twitter: @DanielVerite > > -- Adrian Klaver adrian.klaver@xxxxxxxxxxx -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
