Re: Index of expression over table row or column - Mailing list pgsql-docs

From David G. Johnston
Subject Re: Index of expression over table row or column
Date
Msg-id CAKFQuwZQmoor7GUKdSs9-Yn1fHaTdQzmZ5VWBNdsRiWhH1H-=A@mail.gmail.com
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In response to Index of expression over table row or column  (Steve Lau <stevelauc@outlook.com>)
List pgsql-docs
On Tuesday, October 15, 2024, Steve Lau <stevelauc@outlook.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.

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