Thread: Re: Size of pg_rewrite

Matthias van de Meent <boekewurm+postgres@gmail.com> writes:

> But, as text literal concatenations don't seem to get constant folded
> before storing them in the rules table, this rewrite of the views
> would result in long lines in the system_views.sql file, or we'd have
> to deal with the additional overhead of the append operator and cast
> nodes.

There is no need to use the concatenation operator to split array
constants across multiple lines. Newlines are fine either inside the
string (between array elements), or between two string string literals
(which become one string constant at parse time).

https://www.postgresql.org/docs/current/sql-syntax-lexical.html#SQL-SYNTAX-STRINGS

ilmari@[local]:5432 ~=# select
ilmari@[local]:5432 ~-# '{foo,
ilmari@[local]:5432 ~'# bar}'::text[],
ilmari@[local]:5432 ~-# '{bar,'
ilmari@[local]:5432 ~-# 'baz}'::text[];
┌───────────┬───────────┐
│   text    │   text    │
├───────────┼───────────┤
│ {foo,bar} │ {bar,baz} │
└───────────┴───────────┘
(1 row)


- ilmari

On Fri, 8 Apr 2022 at 17:20, Dagfinn Ilmari Mannsåker <ilmari@ilmari.org> wrote:
>
> Matthias van de Meent <boekewurm+postgres@gmail.com> writes:
>
> > But, as text literal concatenations don't seem to get constant folded
> > before storing them in the rules table, this rewrite of the views
> > would result in long lines in the system_views.sql file, or we'd have
> > to deal with the additional overhead of the append operator and cast
> > nodes.
>
> There is no need to use the concatenation operator to split array
> constants across multiple lines. Newlines are fine either inside the
> string (between array elements), or between two string string literals
> (which become one string constant at parse time).

Ah, neat, that saves some long lines in the system_views file. I had
already tried the "auto-concatenate two consecutive string literals",
but that try failed in initdb, so now I'm not sure what happened
there.

Thanks!

-Matthias