Horton

Re: Variable substitution in psql backtick expansion

Fabien COELHO <coelho@cri.ensmp.fr>

View thread View on postgr.es
From: Fabien COELHO <coelho@cri.ensmp.fr>
To: Daniel Verite <daniel@manitou-mail.org>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, PostgreSQL Developers <pgsql-hackers@postgreSQL.org>
Date: 2017-04-03T22:19:39Z
Lists: pgsql-hackers 
> \set d sqrt(1 + random(1000) * 17)
> \echo :d
> sqrt(1+random(1000)*17)
>
> I assume we want to keep that pre-existing behavior of \set in
> psql,

Ok. So no interpreted expression ever in psql's \set for backward 
compatibility.

> that is, making a copy of that string and associating a name to it, 
> whereas I guess pgbench computes a value from it and stores that value.

Actually it stores the parsed tree, ready to be executed.

-- 
Fabien.

Commits

  1. Add psql variables showing server version and psql version.

  2. Reformat psql's --help=variables output.

  3. Remove reinvention of stringify macro.

  4. Allow psql variable substitution to occur in backtick command strings.