Horton

Re: Handle infinite recursion in logical replication setup

Peter Smith <smithpb2250@gmail.com>

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From: Peter Smith <smithpb2250@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: vignesh C <vignesh21@gmail.com>, "Jonathan S. Katz" <jkatz@postgresql.org>, Dilip Kumar <dilipbalaut@gmail.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, "kuroda.hayato@fujitsu.com" <kuroda.hayato@fujitsu.com>, "shiy.fnst@fujitsu.com" <shiy.fnst@fujitsu.com>
Date: 2022-07-25T23:13:17Z
Lists: pgsql-hackers 
On Mon, Jul 25, 2022 at 6:54 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> On Mon, Jul 25, 2022 at 12:58 PM Peter Smith <smithpb2250@gmail.com> wrote:
> >
...
> >
> > Q2. parse_subscription_options
> >
> > Similarly, in the code (parse_subscription_options), I did not
> > understand why the checks for special name values are implemented
> > differently:
> >
> > The new 'origin' code is using pg_strcmpcase to check special values
> > (none/any), and the old 'slot_name' code uses case-sensitive strcmp to
> > check the special value (none).
> >
>
> We have a restriction for slot_names for lower case letters (aka
> "Replication slot names may only contain lower case letters, numbers,
> and the underscore character.") whereas there is no such restriction
> in origin name, that's why the check is different. So, if you try with
> slot_name = 'NONE', you will get the error.
>

2022-07-26 09:06:06.380 AEST [3630] STATEMENT:  create subscription
mysub connection 'host=localhost' publication mypub with
(slot_name='None', enabled=false, create_slot=false);
ERROR:  replication slot name "None" contains invalid character
HINT:  Replication slot names may only contain lower case letters,
numbers, and the underscore character.

You are right. Thanks for the explanation.

(Aside: Probably that error message wording ought to say "contains
invalid characters" instead of "contains invalid character")

------
Kind Regards,
Peter Smith.
Fujitsu Australia

Commits

  1. Improved CREATE SUBSCRIPTION message for clarity

  2. Fix the test case introduced by commit 8756930190.

  3. Raise a warning if there is a possibility of data from multiple origins.

  4. Add wait_for_subscription_sync for TAP tests.

  5. Bump catversion for commit d8cd0c6c95c0120168df93aae095df4e0682a08a.

  6. Allow users to skip logical replication of data having origin.

  7. Improve two comments related to a boolean DefElem's value

  8. doc: Fix man page whitespace issues