On Wed, Mar 11, 2026 at 2:25 AM Masahiko Sawada <[email protected]> wrote: > > On Wed, Mar 4, 2026 at 3:01 AM Amit Kapila <[email protected]> wrote: > > > > On Wed, Mar 4, 2026 at 2:49 PM shveta malik <[email protected]> wrote: > > > > > > On Wed, Mar 4, 2026 at 1:54 PM vignesh C <[email protected]> wrote: > > > > > > > > Here is an updated version with a couple of typos fixed and separated > > > > the describe table query based on versions which make it more easier > > > > to read. > > > > > > > > > > v56 LGTM. > > > > > > > Pushed. > > Sorry for joining the discussion late. > > I've tried with the new EXCEPT clause and I have some questions about > the newly introduced syntax. With this feature, we can now write: > > CREATE PUBLICATION pub FOR ALL TABLES EXCEPT TABLE (a, b, c); > > The exclusion table list is written in the form of TABLE (a, b, c) but > it's quite different from the inclusion table list we can specify > (e.g., TABLE a, TABLE b, TABLE c). I'm concerned that it could confuse > users. Have these points already been discussed? Also, isn't the TABLE > after EXCEPT redundant? >
Thanks for the question. Yes, these concerns were discussed earlier when the EXCEPT syntax was introduced. The current syntax: CREATE PUBLICATION pub FOR ALL TABLES EXCEPT TABLE (a, b, c); was chosen intentionally, mainly for extensibility and to avoid ambiguity in future enhancements. 1. TABLE keyword after EXCEPT At first glance, the TABLE keyword might appear redundant. However, it becomes important if we later extend the syntax to allow excluding other object types, such as schemas or sequences. For example: CREATE PUBLICATION pub FOR ALL TABLES EXCEPT SCHEMA (s1, s2), EXCEPT TABLE (t1, t2); or potentially more complex combinations such as: CREATE PUBLICATION pub FOR TABLES, SEQUENCES IN SCHEMA sch1 EXCEPT TABLE (t1), EXCEPT SEQUENCE (s1); In such cases, explicitly specifying TABLE (or SCHEMA, SEQUENCE, etc.) after EXCEPT avoids ambiguity and keeps the syntax consistent. 2. Parentheses around the exclusion list Parentheses are required to clearly separate the excluded objects from other elements in the publication definition, especially when mixed with inclusion clauses. For example, consider a future case like: CREATE PUBLICATION pub FOR TABLES IN SCHEMA s1 EXCEPT TABLE (t1, t2), TABLE t3; Here it is clear that t1 and t2 are excluded, while t3 is explicitly included. Without parentheses, a statement like: CREATE PUBLICATION pub FOR TABLES IN SCHEMA s1 EXCEPT TABLE t1, t2, TABLE t3; would be harder to interpret and potentially ambiguous. So although the syntax differs slightly from the existing inclusion list (e.g., TABLE a, b), requiring both the TABLE keyword and parentheses after EXCEPT helps keep the grammar unambiguous and makes the syntax easier to extend in the future. Original discussion is at [1]. [1]: https://www.postgresql.org/message-id/CAJpy0uB%3DJxTYXOB7VmrhVLR%2B1PG0%3DTtHuGekaqibOPpo2UBLiQ%40mail.gmail.com thanks Shveta
