Re: Disallow UPDATE/DELETE on table with unpublished generated column as REPLICA IDENTITY

On Tue, 19 Nov 2024 at 00:36, Shlok Kyal <shlok(dot)kyal(dot)oss(at)gmail(dot)com> wrote:
>
> On Mon, 18 Nov 2024 at 19:19, vignesh C <vignesh21(at)gmail(dot)com> wrote:
> >
> > On Mon, 18 Nov 2024 at 13:07, Shlok Kyal <shlok(dot)kyal(dot)oss(at)gmail(dot)com> wrote:
> > >
> > > Thanks for providing the comments.
> > >
> > > On Sat, 16 Nov 2024 at 17:29, vignesh C <vignesh21(at)gmail(dot)com> wrote:
> > >
> > > I have attached the updated version of the patch.
> >
> > Few comments:
> > 1) We have the following check for cols validation and rf validation:
> > /*
> > * If we know everything is replicated and the column list is invalid
> > * for update and delete, there is no point to check for other
> > * publications.
> > */
> > if (pubdesc->pubactions.pubinsert && pubdesc->pubactions.pubupdate &&
> > pubdesc->pubactions.pubdelete && pubdesc->pubactions.pubtruncate &&
> > !pubdesc->cols_valid_for_update && !pubdesc->cols_valid_for_delete)
> > break;
> >
> > Should we do this for replident_valid_for_update and
> > replident_valid_for_delete also?
> >
> Yes, we can add this check.
>
> > 2) This variable is not required, there is a warning:
> > publicationcmds.c: In function ‘replident_has_unpublished_gen_col’:
> > publicationcmds.c:486:41: warning: unused variable ‘x’ [-Wunused-variable]
> Fixed
>
> I have fixed the comments and attached an updated patch.

To ensure easy backtracking after the patch is committed, we should
include a brief explanation for the test removal in the commit
message:
diff --git a/src/test/subscription/t/100_bugs.pl
b/src/test/subscription/t/100_bugs.pl
index cb36ca7b16..794b928f50 100644
--- a/src/test/subscription/t/100_bugs.pl
+++ b/src/test/subscription/t/100_bugs.pl
@@ -377,8 +377,8 @@ $node_publisher->safe_psql('postgres', "DROP
PUBLICATION tap_pub_sch");
$node_publisher->stop('fast');
$node_subscriber->stop('fast');

-# The bug was that when the REPLICA IDENTITY FULL is used with dropped or
-# generated columns, we fail to apply updates and deletes
+# The bug was that when the REPLICA IDENTITY FULL is used with dropped
+# we fail to apply updates and deletes
$node_publisher->rotate_logfile();
$node_publisher->start();

@@ -389,18 +389,14 @@ $node_publisher->safe_psql(
'postgres', qq(
CREATE TABLE dropped_cols (a int, b_drop int, c int);
ALTER TABLE dropped_cols REPLICA IDENTITY FULL;
- CREATE TABLE generated_cols (a int, b_gen int GENERATED ALWAYS AS (5
* a) STORED, c int);
- ALTER TABLE generated_cols REPLICA IDENTITY FULL;
- CREATE PUBLICATION pub_dropped_cols FOR TABLE dropped_cols, generated_cols;
+ CREATE PUBLICATION pub_dropped_cols FOR TABLE dropped_cols;

Regards,
Vignesh