Re: Index of expression over table row or column

On Tuesday, October 15, 2024, Steve Lau <stevelauc(at)outlook(dot)com> wrote:
>
> I am reading this documentation[1], and it has a sentence that I don’t
> quite understand: "The index columns (key values) can be either simple
> columns of the underlying table or expressions over the table rows.”, I am
> thinking that for the index of expressions, aren’t those expressions over
> table column?
>
>
Agreed.

The description for pg_index.indkey uses the phrasing “an expression over
the table columns” and this should be made to match.

I could maybe argue for a singular row, meaning the expression can
reference any or all of a single row’s columns, but not plural and not with
existing wording using “table columns”.

David J.