Re: why can't a table be part of the same publication as its schema - Mailing list pgsql-hackers

From Jonathan S. Katz
Subject Re: why can't a table be part of the same publication as its schema
Date
Msg-id de91a8ab-0c26-f6d8-9951-9cd098acba1c@postgresql.org
Whole thread Raw
In response to Re: why can't a table be part of the same publication as its schema  (Mark Dilger <mark.dilger@enterprisedb.com>)
Responses Re: why can't a table be part of the same publication as its schema
List pgsql-hackers
On 9/20/22 10:55 AM, Mark Dilger wrote:
> 
> 
>> On Sep 19, 2022, at 8:03 PM, Jonathan S. Katz <jkatz@postgresql.org> wrote:
>>
>> "When a partitioned table is added to a publication, all of its existing and future partitions are implicitly
consideredto be part of the publication."[10]
 
>>
>> Additionally, this is the behavior that is already present in "FOR ALL TABLES":
>>
>> "Marks the publication as one that replicates changes for all tables in the database, including tables created in
thefuture."[10]
 
>>
>> I don't think we should change this behavior that's already in logical replication.
> 
> The existing behavior in logical replication doesn't have any "IN SCHEMA" qualifiers.

This behavior exists "FOR ALL TABLES" without the "IN SCHEMA" qualifier. 
This was discussed multiple times on the original thread[1].

> 
>> While I understand the reasons why "GRANT ... ALL TABLES IN SCHEMA" has a different behavior (i.e. it's not applied
tofuture objects) and do not advocate to change it, I have personally been affected where I thought a permission would
beapplied to all future objects, only to discover otherwise. I believe it's more intuitive to think that "ALL" applies
to"everything, always."
 
> 
> The conversation is focusing on what "ALL TABLES" means, but the ambiguous part is what "IN SCHEMA" means.  In GRANT
itmeans "currently in schema, computed now."  We are about to create confusion by adding the "IN SCHEMA" phrase to
publicationcommands meaning "later in schema, computed then."  A user who diligently consults the documentation for one
commandto discover what "IN SCHEMA" means may fairly, but wrongly, assume it means the same thing in another command.
 

I tried to diligently read the sections where we talk about granting + 
privileges[2][3] to see what it says about "ALL * IN SCHEMA". Unless I 
missed it, and I read through it twice, it does not explicitly state 
whether or not "GRANT" applies to all objects at only that given moment, 
or to future objects of that type which are created in that schema. 
Maybe the behavior is implied or is part of the standard, but it's not 
currently documented. We do link to "ALTER DEFAULT PRIVILEGES" at the 
bottom of the GRANT[2] docs, but we don't give any indication as to why.

(This is also to say we should document in GRANT that ALL * IN SCHEMA 
does not apply to future objects; if you need that behavior use ALTER 
DEFAULT PRIVILEGES. Separate thread :)

I understand there is a risk of confusion of the similar grammar across 
commands, but the current command in logical replication has this is 
building on the existing behavior.

Thanks,

Jonathan

[1] 
https://www.postgresql.org/message-id/flat/CALDaNm0OANxuJ6RXqwZsM1MSY4s19nuH3734j4a72etDwvBETQ%40mail.gmail.com
[2] https://www.postgresql.org/docs/current/sql-grant.html
[3] https://www.postgresql.org/docs/current/ddl-priv.html

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