On 5/6/25 9:15 AM, Álvaro Herrera wrote:
> On 2025-May-05, Jonathan S. Katz wrote:
>
>> ### Other Highlights
>>
>> Starting with PostgreSQL 18, data checksums, which are used to validate the integrity of stored data, are now
enabledby default on new PostgreSQL clusters. You can choose to disable this behavior using the `initdb
--no-data-checksums`command.
>>
>> `pg_createsubscriber` now supports an `--all` flag so you can create logical replicas for all databases in an
instancewith a single command. Additionally, PostgreSQL 18 lets you create the schema definition of a foreign table
usingthe definition of a local table using the `CREATE FOREIGN TABLE ... LIKE` command.
>
> In this section I would add the work on not-null and NOT ENFORCED
> constraints, not because I think they are very important, but because
> they have the potential to break stuff; and if they do, it would be very
> useful to know before GA. Maybe something like
>
> Some constraint features have been revised: foreign-key and check
> constraints can now be made NOT ENFORCED and altered into
> enforceability; not-null constraints now preserve their names as
> mandated by the SQL-standard, support the NOT VALID and NO INHERIT
> clauses, as well as behave more consistently on inheritance situations.
>
>
> Now that I look again, I see no mention of temporal UNIQUE, PRIMARY KEY
> and FOREIGN KEY constraints (commits fc0438b4e805 and 89f908a6d0ac). I
> think they are a very important feature, perhaps they even warrant a
> section of their own. So maybe I'd suggest to add a section
> "### Constraints" and put all these things in there.
Here's the next update (CCing folks who commented); I added a sentence
on the new constraints that are available in the developer experience
section, and the sentence around the behavior towards the bottom. Please
let me know if you think this sufficiently explains the feature.
Thanks for the review!
Jonathan
