Re: SYSTEM_USER reserved word implementation

On 9/7/22 07:46, Drouvot, Bertrand wrote:
> Except the Nit above, that looks all good to me.

A few additional comments:

> + assigned a database role. It is represented as
> + <literal>auth_method:identity</literal> or
> + <literal>NULL</literal> if the user has not been authenticated (for
> + example if <xref linkend="auth-trust"/> has been used).
> + </para></entry>

This is rendered as

... (for example if Section 21.4 has been used).

which IMO isn't too helpful. Maybe a <link> would read better than an
<xref>?

Also, this function's placement in the docs (with the System Catalog
Information Functions) seems wrong to me. I think it should go up above
in the Session Information Functions, with current_user et al.

> + /* Build system user as auth_method:authn_id */
> + char *system_user;
> + Size authname_len = strlen(auth_method);
> + Size authn_id_len = strlen(authn_id);
> +
> + system_user = palloc0(authname_len + authn_id_len + 2);
> + strcat(system_user, auth_method);
> + strcat(system_user, ":");
> + strcat(system_user, authn_id);

If we're palloc'ing anyway, can this be replaced with a single psprintf()?

> + /* Initialize SystemUser now that MyClientConnectionInfo is restored. */
> + InitializeSystemUser(MyClientConnectionInfo.authn_id,
> + hba_authname(MyClientConnectionInfo.auth_method));

It makes me a little nervous to call hba_authname(auth_method) without
checking to see that auth_method is actually valid (which is only true
if authn_id is not NULL).

We could pass the bare auth_method index, or update the documentation
for auth_method to state that it's guaranteed to be zero if authn_id is
NULL (and then enforce that).

> case SVFOP_CURRENT_USER:
> case SVFOP_USER:
> case SVFOP_SESSION_USER:
> + case SVFOP_SYSTEM_USER:
> case SVFOP_CURRENT_CATALOG:
> case SVFOP_CURRENT_SCHEMA:
> svf->type = NAMEOID;

Should this be moved to use TEXTOID instead?

Thanks,
--Jacob