Re: Logical replication without a Primary Key

On 12/07/2017 12:39 PM, Andres Freund wrote:
>
> Not a problem. If you updated both rows, then there's two cases:
> a) the update actually changed the column values. In which case the first per-row
>     change that's replicated updates the first row, but the second one won't
>     again find it as matching in all columns.
> b) the update didn't actually change anything. In which case the same
>     row gets updated twice, but because the column values didn't change,
>     that doesn't matter.

I may be misunderstanding what is said above but if I ran a test:

Publisher:
reptest=# \d foorep
              Table "public.foorep"
  Column | Type | Collation | Nullable | Default
--------+------+-----------+----------+---------
  one    | text |           |          |
  two    | text |           |          |
Publications:
     "reptestpub"

reptest=# select * from foorep;
  one | two
-----+-----
  c   | b
  c   | b
  c   | b
(3 rows)

reptest=# update foorep set one = 'd';
UPDATE 3
reptest=# select * from foorep;
  one | two
-----+-----
  d   | b
  d   | b
  d   | b
(3 rows)

Subscriber before Publisher update:
reptest=# select * from foorep ;
  one | two
-----+-----
  c   | b
  c   | b
  c   | b
(3 rows)

Subscriber after Publisher update:
reptest=# select * from foorep ;
  one | two
-----+-----
  d   | b
  d   | b
  d   | b
(3 rows)

This is the behavior I was expecting. As I said, I may have 
misunderstood the responses but it is acting as I would expect.

Thanks!

JD

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