RE: row filtering for logical replication

On Mon, Dec 13, 2021 5:49 PM Peter Smith <smithpb2250(at)gmail(dot)com> wrote:
> PSA the v46* patch set.
>
> Here are the main differences from v45:
> 0. Rebased to HEAD
> 1. Integrated many comments, docs, messages, code etc from Euler's patch
> [Euler 6/12] 2. Several bugfixes 3. Patches are merged/added
>
> ~~
>
> Bugfix and Patch Merge details:
>
> v46-0001 (main)
> - Merged from v45-0001 (main) + v45-0005 (exprstate)
> - Fix for mem leak reported by Greg (off-list)
>
> v46-0002 (validation)
> - Merged from v45-0002 (node validation) + v45-0006 (replica identity
> validation)
>
> v46-0003
> - Rebased from v45-0003
> - Fix for partition column order [Houz 9/12]
> - Fix for core dump reported by Tang (off-list)
>
> v46-0004 (tab-complete and dump)
> - Rebased from v45-0004
>
> v46-0005 (for all tables)
> - New patch
> - Fix for FOR ALL TABLES [Tang 7/12]
>

Thanks for updating the patch.

When reviewing the patch, I found the patch allows using system columns in
row filter expression.
---
create publication pub for table test WHERE ('(0,1)'::tid=ctid);
---

Since we can't create index on system column and most
existing expression feature(index expr,partition expr,table constr) doesn't
allow using system column, I think it might be better to disallow using system
column when creating or altering the publication. We can check like:

rowfilter_walker(Node *node, Relation relation)
...
if (var->varattno < 0)
ereport(ERROR,
errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
errmsg("cannot use system column \"%s\" in column generation expression",
...

Best regards,
Hou zj