Dear Vignesh,
Thanks for rebasing the patch! Before reviewing deeply, I want to confirm the
specification.
I understood like below based on the documentation.
- If publish_generated_columns is false, the publication won't replicate
generated columns
- If publish_generated_columns is true, the behavior on the subscriber depends
on the table column:
- If it is a generated column even on the subscriber, it causes an ERROR.
- If it is a regular column, the generated value is replicated.
- If the column is missing, it causes an ERROR.
However, below test implies that generated columns can be replicated even if
publish_generated_columns is false. Not sure...
```
# Verify that incremental replication of generated columns occurs
# when they are included in the column list, regardless of the
# publish_generated_columns option.
$result =
$node_subscriber->safe_psql('postgres', "SELECT * FROM tab3 ORDER BY a");
is( $result, qq(|2
|4
|6
|8),
'tab3 incremental replication, when publish_generated_columns=false');
```
Also, I've tested the case both pub and sub had the generated column, but the
ERROR was strange for me.
```
test_pub=# CREATE TABLE gencoltable (a int PRIMARY KEY, b int GENERATED ALWAYS
AS (a * 2) STORED);
test_pub=# CREATE PUBLICATION pub FOR TABLE gencoltable(a, b) WITH
(publish_generated_columns = true);
test_pub=# INSERT INTO gencoltable (a) VALUES (generate_series(1, 10));
test_sub=# CREATE TABLE gencoltable (a int PRIMARY KEY, b int GENERATED ALWAYS
AS (a * 2) STORED);
test_sub=# CREATE SUBSCRIPTION sub CONNECTION ... PUBLICATION pub;
-> ERROR: logical replication target relation "public.gencoltable" is missing
replicated column: "b"
```
The attribute existed on the sub but it was reported as missing column. I think
we should somehow report like "generated column on publisher is replicated the
generated column on the subscriber".
Best regards,
Hayato Kuroda
FUJITSU LIMITED
