On Tuesday, April 22, 2025, Peter Smith <smithpb2...@gmail.com> wrote:
> Hi, > > While re-reading documentation about logical replication of generated > columns, I came across this paragraph in the CREATE PUBLICATION ... > FOR TABLE description [1]. > > ---- > When a column list is specified, only the named columns are > replicated. The column list can contain stored generated columns as > well. If no column list is specified, all table columns (except > generated columns) are replicated through this publication, including > any columns added later. It has no effect on TRUNCATE commands. See > Section 29.5 for details about column lists. > ---- > > That "except generated columns" part is not strictly correct because > it fails to account for the 'publish_generated_columns' parameter. > I've suggested a more accurate description below. > > > SUGGESTION > ---- > When a column list is specified, only the named columns are > replicated. Stored generated columns may be included in the list. > Specifying a column list has no effect on TRUNCATE commands. See > Section 29.5 for details about column lists. If no column list is > specified, all table columns are replicated through this publication, > including any columns added later. Generated columns are included in > this case only if publish_generated_columns is set to stored. > ---- > > I've attached a patch to implement this suggested wording. > > Thoughts? > > ====== > [1] https://www.postgresql.org/docs/devel/sql-createpublication.html#SQL- > CREATEPUBLICATION-PARAMS-FOR-TABLE > In the column list I would stick to mentioning what cannot be specified, since it would be assumed by default that any column on the table is fair game. I believe that means not mentioning stored generated and instead mentioning virtual generated. It really seems odds mentioning stored generated being allowed before mentioning when they are optional, default excluded. Alternative: The optional column list may include any non-virtual columns of the table. If omitted, tables publish all (including future) non-generated columns by default, and may publish stored generated columns if the publication option publish_generated_columns is set to stored. See Section 29.5 for details about column lists. I don’t get why truncate is mentioned here. I omitted it intentionally. David J.
