Re: BUG #15646: Inconsistent behavior for current_setting/set_config

On 2/20/19 11:10 AM, PG Bug reporting form wrote:
> The following bug has been logged on the website:
>
> Bug reference: 15646
> Logged by: Eugen Konkov
> Email address: kes-kes(at)yandex(dot)ru
> PostgreSQL version: 10.4
> Operating system: (Debian 10.4-2.pgdg90+1)
> Description:
>
> Hi.
>
> [documentation](https://www.postgresql.org/docs/11/functions-admin.html#FUNCTIONS-ADMIN-SET)
> describes that:
>
>>set_config sets the parameter setting_name to new_value. If is_local is
> true, the new value will only apply to the current transaction.
>
> Thus if I rollback transaction original value should be available.
>
> But current behavior returns empty string instead of NULL (the initial
> value) after transaction is rolled back. When I restart session, NULL is
> returned again as it is expected.

This has been discussed before and dismissed:
https://www.postgresql.org/message-id/flat/56842412.5000005%40joeconway.com

Personally I agree it is a bug, but I am not sure you will get much
support for that position.

Joe

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