On 2024-03-29 02:42 +0100, David G. Johnston wrote:
> For consideration for the doc portion. The existing wording is too
> imprecise for my liking and just tacking on "expects...create type" is
> jarring.
>
> """
> Creates a typed table, which takes it structure from an existing (name
> optionally schema-qualified) stand-alone composite type i.e., one created
> using CREATE TYPE) though it still produces a new composite type as well.
> The table will have a dependency to the referenced type such cascaded alter
> and drop actions on the type will propagate to the table.
>
> A typed table always has the same column names and data types as the type
> it is derived from, and you cannot specify additional columns. But the
> CREATE TABLE command can add defaults and constraints to the table, as well
> as specify storage parameters.
> """
Thanks, that sounds better. I incorporated that with some minor edits
in the attached v3.
> We do use the term "stand-alone composite" in create type so I'm inclined
> to use it instead of "composite created with CREATE TYPE"; especially in
> the error messages; I'm a bit more willing to add the cross-reference to
> create type in the user docs.
Okay, changed in v3 as well. I used "created with CREATE TYPE" in the
error message because I thought it's clearer to the user. But I see no
reason for not using "stand-alone" here as well if it's the established
term.
--
Erik
>From e9a79e6d5e063098eed4f834b18d576089b38499 Mon Sep 17 00:00:00 2001
From: Erik Wienhold <e...@ewie.name>
Date: Fri, 8 Mar 2024 04:21:56 +0100
Subject: [PATCH v3] Document that typed tables rely on CREATE TYPE
CREATE TABLE OF requires a stand-alone composite type. Clarify that in
the error message. Also reword the docs to better explain the
connection between created table and stand-alone composite type.
Reworded docs provided by David G. Johnston.
---
doc/src/sgml/ref/create_table.sgml | 18 +++++++++---------
src/backend/commands/tablecmds.c | 2 +-
src/test/regress/expected/typed_table.out | 2 +-
3 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/doc/src/sgml/ref/create_table.sgml
b/doc/src/sgml/ref/create_table.sgml
index dfb7822985..5c8c1edaed 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -249,19 +249,19 @@ WITH ( MODULUS <replaceable
class="parameter">numeric_literal</replaceable>, REM
<term><literal>OF <replaceable
class="parameter">type_name</replaceable></literal></term>
<listitem>
<para>
- Creates a <firstterm>typed table</firstterm>, which takes its
- structure from the specified composite type (name optionally
- schema-qualified). A typed table is tied to its type; for
- example the table will be dropped if the type is dropped
- (with <literal>DROP TYPE ... CASCADE</literal>).
+ Creates a <firstterm>typed table</firstterm>, which takes its structure
+ from an existing (name optionally schema-qualified) stand-alone composite
+ type (i.e. created using <xref linkend="sql-createtype"/>) though it
+ still produces a new composite type as well. The table will have
+ a dependency on the referenced type such that cascaded alter and drop
+ actions on the type will propagate to the table.
</para>
<para>
- When a typed table is created, then the data types of the
- columns are determined by the underlying composite type and are
- not specified by the <literal>CREATE TABLE</literal> command.
+ A typed table always has the same column names and data types as the
+ type it is derived from, and you cannot specify additional columns.
But the <literal>CREATE TABLE</literal> command can add defaults
- and constraints to the table and can specify storage parameters.
+ and constraints to the table, as well as specify storage parameters.
</para>
</listitem>
</varlistentry>
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 6741e721ae..8e9dbe4bee 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -6990,7 +6990,7 @@ check_of_type(HeapTuple typetuple)
if (!typeOk)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
- errmsg("type %s is not a composite type",
+ errmsg("type %s is not a stand-alone composite
type",
format_type_be(typ->oid))));
}
diff --git a/src/test/regress/expected/typed_table.out
b/src/test/regress/expected/typed_table.out
index 2e47ecbcf5..745fbde811 100644
--- a/src/test/regress/expected/typed_table.out
+++ b/src/test/regress/expected/typed_table.out
@@ -89,7 +89,7 @@ drop cascades to function get_all_persons()
drop cascades to table persons2
drop cascades to table persons3
CREATE TABLE persons5 OF stuff; -- only CREATE TYPE AS types may be used
-ERROR: type stuff is not a composite type
+ERROR: type stuff is not a stand-alone composite type
DROP TABLE stuff;
-- implicit casting
CREATE TYPE person_type AS (id int, name text);
--
2.44.0
