Re: Index of expression over table row or column

[Steve Lau]

Hi

> On Oct 16, 2024, at 12:17 PM, Laurenz Albe <laurenz.a...@cybertec.at> wrote:
> 
> And what would you say about this (silly) example:
> 
>  CREATE TABLE x (a integer, b integer);
>  CREATE INDEX ON x(hash_record(x));

When I talk about an expression over something, I mainly think about it at the 
AST level, I guess the AST of expression “hash_record(x)” will be something 
like (I tried to parse this statement and print the AST using pg_query.rs, but 
looks like this library does not have an AST type defined, sorry if my guess is 
too incorrect):

FunctionCall {
    name: “hash_record",
    arguments: [
        Table {
            name: "x"
        }
    ]
}

So it is not table columns or rows IMHO.

Regards, Steve.