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Code review for DOMAIN patch.

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This commit is contained in:
Tom Lane
2002-03-20 19:45:13 +00:00
parent 251282d4b7
commit 337b22cb47
37 changed files with 869 additions and 850 deletions
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85
doc/src/sgml/catalogs.sgml
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@ -1,6 +1,6 @@
<!--
Documentation of the system catalogs, directed toward PostgreSQL developers
$Header: /cvsroot/pgsql/doc/src/sgml/catalogs.sgml,v 2.34 2002/03/19 02:18:10 momjian Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/catalogs.sgml,v 2.35 2002/03/20 19:43:24 tgl Exp $
-->
<chapter id="catalogs">
@ -2274,7 +2274,8 @@
This catalog stores information about datatypes. Scalar types
(<quote>base types</>) are created with <command>CREATE TYPE</command>.
A complex type is also created for each table in the database, to
represent the row structure of the table.
represent the row structure of the table. It is also possible to create
derived types with <command>CREATE DOMAIN</command>.
</para>
<table>
@ -2345,11 +2346,10 @@
<entry></entry>
<entry>
<structfield>typtype</structfield> is <literal>b</literal> for
a base type and <literal>c</literal> for a complex type (i.e.,
a table's row type). If <structfield>typtype</structfield> is
<literal>c</literal>, <structfield>typrelid</structfield> is
the OID of the type's entry in
<structname>pg_class</structname>.
a base type, <literal>c</literal> for a complex type (i.e.,
a table's row type), or <literal>d</literal> for a derived type (i.e.,
a domain). See also <structfield>typrelid</structfield>
and <structfield>typbasetype</structfield>.
</entry>
</row>
@ -2382,6 +2382,7 @@
the <structfield>pg_class</structfield> entry that defines the
corresponding table. A table could theoretically be used as a
composite data type, but this is not fully functional.
Zero for non-complex types.
</entry>
</row>
@ -2511,38 +2512,53 @@
</row>
<row>
<entry>typbasetype</entry>
<entry><type>oid</type></entry>
<entry>typnotnull</entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry><para>
<structfield>typbasetype</structfield> is the type that this one is based
on. Normally references the domains parent type, and is 0 otherwise.
<structfield>typnotnull</structfield> represents a NOT NULL
constraint on a type. Presently used for domains only.
</para></entry>
</row>
<row>
<entry>typnotnull</entry>
<entry><type>boolean</type></entry>
<entry></entry>
<entry><para>
<structfield>typnotnull</structfield> represents a NOT NULL
constraint on a type. Used for domains only.
</para></entry>
</row>
<row>
<entry>typbasetype</entry>
<entry><type>oid</type></entry>
<entry>pg_type.oid</entry>
<entry><para>
If this is a derived type (see <structfield>typtype</structfield>),
then <structfield>typbasetype</structfield> identifies
the type that this one is based on. Zero if not a derived type.
</para></entry>
</row>
<row>
<entry>typmod</entry>
<entry><type>integer</type></entry>
<entry>typtypmod</entry>
<entry><type>int4</type></entry>
<entry></entry>
<entry><para>
<structfield>typmod</structfield> records type-specific data
<structfield>typtypmod</structfield> records type-specific data
supplied at table creation time (for example, the maximum
length of a <type>varchar</type> column). It is passed to
type-specific input and output functions as the third
argument. The value will generally be -1 for types that do not
need typmod. This data is copied to
<structfield>pg_attribute.atttypmod</structfield> on creation
of a table using a domain as it's field type.
need typmod. This value is copied to
<structfield>pg_attribute.atttypmod</structfield> when
creating a column of a domain type.
</para></entry>
</row>
<row>
<entry>typndims</entry>
<entry><type>int4</type></entry>
<entry></entry>
<entry><para>
<structfield>typndims</structfield> is the number of array dimensions
for a domain that is an array. (The array element type is
typbasetype.) Zero for non-domains and non-array domains.
This value is copied to
<structfield>pg_attribute.attndims</structfield> when
creating a column of a domain type.
</para></entry>
</row>
@ -2551,9 +2567,9 @@
<entry><type>text</type></entry>
<entry></entry>
<entry><para>
<structfield>typdefaultbin</structfield> is NULL for types without a
default value. If it's not NULL, it contains the internal string
representation of the default expression node.
If <structfield>typdefaultbin</> is not NULL, it is the nodeToString
representation of a default expression for the type. Currently this is
only used for domains.
</para></entry>
</row>
@ -2562,9 +2578,14 @@
<entry><type>text</type></entry>
<entry></entry>
<entry><para>
<structfield>typdefault</structfield> is NULL for types without a
default value. If it's not NULL, it contains the external string
representation of the type's default value.
<structfield>typdefault</> is NULL if the type has no associated
default value. If <structfield>typdefaultbin</> is not NULL,
<structfield>typdefault</> must contain a human-readable version of the
default expression represented by <structfield>typdefaultbin</>. If
<structfield>typdefaultbin</> is NULL and <structfield>typdefault</> is
not, then <structfield>typdefault</> is the external representation of
the type's default value, which may be fed to the type's input
converter to produce a constant.
</para></entry>
</row>
</tbody>

44
doc/src/sgml/ref/create_domain.sgml
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@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_domain.sgml,v 1.3 2002/03/19 02:18:13 momjian Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_domain.sgml,v 1.4 2002/03/20 19:43:28 tgl Exp $
PostgreSQL documentation
-->
@ -23,13 +23,14 @@ PostgreSQL documentation
<date>2002-02-24</date>
</refsynopsisdivinfo>
<synopsis>
CREATE DOMAIN <replaceable class="parameter">domainname</replaceable> <replaceable class="parameter">data_type</replaceable> [ DEFAULT <replaceable>default_expr</> ] [ <replaceable class="PARAMETER">column_constraint</replaceable> [, ... ] ]
CREATE DOMAIN <replaceable class="parameter">domainname</replaceable> [AS] <replaceable class="parameter">data_type</replaceable>
[ DEFAULT <replaceable>default_expr</> ]
[ <replaceable class="PARAMETER">constraint</replaceable> [, ... ] ]
where <replaceable class="PARAMETER">constraint</replaceable> is:
[ CONSTRAINT <replaceable class="PARAMETER">constraint_name</replaceable> ]
{ NOT NULL | NULL <!-- | UNIQUE | PRIMARY KEY |
CHECK (<replaceable class="PARAMETER">expression</replaceable>) |
REFERENCES <replaceable class="PARAMETER">reftable</replaceable> [ ( <replaceable class="PARAMETER">refcolumn</replaceable> ) ] [ MATCH FULL | MATCH PARTIAL ]
[ ON DELETE <replaceable class="parameter">action</replaceable> ] [ ON UPDATE <replaceable class="parameter">action</replaceable> ] --> }
<!-- [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ] -->
{ NOT NULL | NULL }
</synopsis>
<refsect2 id="R2-SQL-CREATEDOMAIN-1">
@ -67,23 +68,26 @@ CREATE DOMAIN <replaceable class="parameter">domainname</replaceable> <replaceab
<replaceable>default_expr</replaceable></literal></term>
<listitem>
<para>
The <literal>DEFAULT</> clause assigns a default data value for
the column whose column definition it appears within. The value
is any variable-free expression (subselects and cross-references
to other columns in the current table are not allowed). The
The <literal>DEFAULT</> clause specifies a default value for
columns of the domain data type. The value
is any variable-free expression (but subselects are not allowed).
The
data type of the default expression must match the data type of the
domain.
</para>
<para>
The default expression will be used in any insert operation that
does not specify a value for the domain. If there is no default
does not specify a value for the column. If there is no default
for a domain, then the default is NULL.
</para>
<note>
<para>
The default of a column will be tested before that of the domain.
If a default value is specified for a particular column, it
overrides any default associated with the domain. In turn,
the domain default overrides any default value associated with
the underlying data type.
</para>
</note>
</listitem>
@ -93,7 +97,7 @@ CREATE DOMAIN <replaceable class="parameter">domainname</replaceable> <replaceab
<term><literal>CONSTRAINT <replaceable class="PARAMETER">constraint_name</replaceable></literal></term>
<listitem>
<para>
An optional name for a domain. If not specified,
An optional name for a constraint. If not specified,
the system generates a name.
</para>
</listitem>
@ -103,7 +107,7 @@ CREATE DOMAIN <replaceable class="parameter">domainname</replaceable> <replaceab
<term><literal>NOT NULL</></term>
<listitem>
<para>
The column is not allowed to contain NULL values. This is
Values of this domain are not allowed to be NULL. This is
equivalent to the column constraint <literal>CHECK (<replaceable
class="PARAMETER">column</replaceable> NOT NULL)</literal>.
</para>
@ -114,7 +118,7 @@ CREATE DOMAIN <replaceable class="parameter">domainname</replaceable> <replaceab
<term><literal>NULL</></term>
<listitem>
<para>
The column is allowed to contain NULL values. This is the default.
Values of this domain are allowed to be NULL. This is the default.
</para>
<para>
@ -175,7 +179,7 @@ CREATE DOMAIN
Domains are useful for abstracting common fields between tables into
a single location for maintenance. An email address column may be used
in several tables, all with the same properties. Define a domain and
use that rather than setting up each tables constraints individually.
use that rather than setting up each table's constraints individually.
</para>
</refsect1>
@ -195,9 +199,9 @@ CREATE TABLE countrylist (id INT4, country country_code);
<title>Compatibility</title>
<para>
This <command>CREATE DOMAIN</command> command is a
<productname>PostgreSQL</productname> extension. CHECK and FOREIGN KEY
constraints are currently unsupported.
SQL99 defines CREATE DOMAIN, but says that the only allowed constraint
type is CHECK constraints. CHECK constraints for domains are not yet
supported by <productname>PostgreSQL</productname>.
</para>
</refsect1>

30
doc/src/sgml/ref/drop_domain.sgml
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@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/ref/drop_domain.sgml,v 1.3 2002/03/19 02:18:13 momjian Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/ref/drop_domain.sgml,v 1.4 2002/03/20 19:43:28 tgl Exp $
PostgreSQL documentation
-->
@ -23,7 +23,7 @@ PostgreSQL documentation
<date>1999-07-20</date>
</refsynopsisdivinfo>
<synopsis>
DROP DOMAIN <replaceable class="PARAMETER">domainname</replaceable> [, ...]
DROP DOMAIN <replaceable class="PARAMETER">domainname</replaceable> [, ...] [ CASCADE | RESTRICT ]
</synopsis>
<refsect2 id="R2-SQL-DROPDOMAIN-1">
@ -43,6 +43,25 @@ DROP DOMAIN <replaceable class="PARAMETER">domainname</replaceable> [, ...]
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>CASCADE</></term>
<listitem>
<para>
Automatically drop objects that depend on the domain. This
behavior is not currently supported.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>RESTRICT</></term>
<listitem>
<para>
Do not drop dependent objects. This is the default.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</refsect2>
@ -117,7 +136,7 @@ ERROR: RemoveDomain: type '<replaceable class="parameter">domainname</replaceab
To remove the <type>box</type> domain:
<programlisting>
DROP DOMAIN box RESTRICT;
DROP DOMAIN box;
</programlisting>
</para>
</refsect1>
@ -134,9 +153,8 @@ DROP DOMAIN box RESTRICT;
<synopsis>
DROP DOMAIN <replaceable>name</replaceable> { CASCADE | RESTRICT }
</synopsis>
<productname>PostgreSQL</productname> enforces the existance of
RESTRICT or CASCADE but ignores their enforcement against the
system tables.
<productname>PostgreSQL</productname> accepts only the RESTRICT
option, and currently does not check for existence of dependent objects.
</para>
</refsect1>

19
doc/src/sgml/ref/psql-ref.sgml
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@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/ref/psql-ref.sgml,v 1.64 2002/03/19 02:32:19 momjian Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/ref/psql-ref.sgml,v 1.65 2002/03/20 19:43:30 tgl Exp $
PostgreSQL documentation
-->
@ -419,21 +419,10 @@ testdb=>
<term><literal>\dD</literal> [ <replaceable class="parameter">pattern</replaceable> ]</term>
<listitem>
<para>
Lists all database domains.
Lists all available domains (derived types).
If <replaceable class="parameter">pattern</replaceable>
(a regular expression) is specified, only matching domains are shown.
</para>
<para>
Descriptions for objects can be generated with the <command>COMMENT ON</command>
<acronym>SQL</acronym> command.
</para>
<note>
<para>
<productname>PostgreSQL</productname> stores the object descriptions in the
pg_description system table.
</para>
</note>
</listitem>
</varlistentry>