Re: wrong relkind error messages

On 2020-Apr-13, Robert Haas wrote:

> + ereport(ERROR,
> + (errcode(ERRCODE_WRONG_OBJECT_TYPE),
> + errmsg("action cannot be performed on relation \"%s\"",
> + RelationGetRelationName(rel)),
>
> Super-vague.

Maybe, but note that the patch proposed to replace this current error
message:
ERROR: foo is not an index or foreign table
with
ERROR: action cannot be performed on "foo"
DETAIL: "foo" is a materialized view.

or, if we're to adopt Tom's proposed wording,

ERROR: cannot perform action on relation "ti"
DETAIL: This operation is not supported for materialized views.

so it's not like this is making things any worse; the error was already
super-vague.

This could be improved if we had stringification of ALTER TABLE
subcommand types:

ERROR: ALTER TABLE ... ADD COLUMN cannot be performed on "foo"
DETAIL: "foo" is a gummy bear.
or
ERROR: ALTER TABLE ... ADD COLUMN cannot be performed on foo
DETAIL: This action cannot be performed on gummy bears.

but that seems material for a different patch.

--
Álvaro Herrera https://www.2ndQuadrant.com/
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