Re: Index of expression over table row or column

Hi

> On Oct 16, 2024, at 12:17 PM, Laurenz Albe <laurenz(dot)albe(at)cybertec(dot)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.