Re: Refactor handling of database attributes between pg_dump and pg_dumpall

On Sat, Sep 30, 2017 at 3:31 AM, Robert Haas <robertmhaas@gmail.com> wrote:

> On Fri, Sep 29, 2017 at 12:44 AM, Vaishnavi Prabakaran
> <vaishnaviprabakaran@gmail.com> wrote:
> > Option name "--enable-pgdumpall-behaviour"  is very generic
>
> Yeah, that's a terrible name, at least in my opinion.
>

OK. I will use a new name based on the discussion.


> and it is better
> > to rename it to something that reflects its functionality like
> > --skip-default-db-create/--no-default-db-create
>
> But I wonder why this patch needs a new option at all?
>

There are some differences in handling database objects
between pg_dump and pg_dumpall, To retain both pg_dump
and pg_dumpall behavior even after refactoring, this option
is added. Currently this option is used mainly for the three
purposes.

1. Don't print unnecessary CREATE DATABASE options like
ENCODING, LC_COLLATE and LC_CTYPE options if the
default encoding is same with the above values.

The above behavior is as per the pg_dumpall, but it can be
changed to print irrespective of the default encoding.

2. Do not dump postgres and template0 databases.

3. Set default_transaction_read_only = off.

As per the following comment in pg_dumpall, based on that flag
the GUC is set, to retain the same behavior even after this
refactoring.

/*
* Restore will need to write to the target cluster.  This connection
* setting is emitted for pg_dumpall rather than in the code also used
* by pg_dump, so that a cluster with databases or users which have
* this flag turned on can still be replicated through pg_dumpall
* without editing the file or stream.  With pg_dump there are many
* other ways to allow the file to be used, and leaving it out allows
         * users to protect databases from being accidental restore targets.
*/
fprintf(OPF, "SET default_transaction_read_only = off;\n\n");

we can remove the usage -1 and retain the usage-2 with modified option
name as --no-default-database or similar.

Any opinions about the usage-3, In case if we need to retain that change,
any best solution to the option name?

Regards,
Hari Babu
Fujitsu Australia