diff options
Diffstat (limited to 'doc/src/sgml/ref/create_table.sgml')
| -rw-r--r-- | doc/src/sgml/ref/create_table.sgml | 22 |
1 files changed, 13 insertions, 9 deletions
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml index 417498f71db..9acbc4dd34d 100644 --- a/doc/src/sgml/ref/create_table.sgml +++ b/doc/src/sgml/ref/create_table.sgml @@ -65,7 +65,7 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI NULL | CHECK ( <replaceable class="parameter">expression</replaceable> ) [ NO INHERIT ] | DEFAULT <replaceable>default_expr</replaceable> | - GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) STORED | + GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) [ STORED | VIRTUAL ] | GENERATED { ALWAYS | BY DEFAULT } AS IDENTITY [ ( <replaceable>sequence_options</replaceable> ) ] | UNIQUE [ NULLS [ NOT ] DISTINCT ] <replaceable class="parameter">index_parameters</replaceable> | PRIMARY KEY <replaceable class="parameter">index_parameters</replaceable> | @@ -725,8 +725,9 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM <term><literal>INCLUDING GENERATED</literal></term> <listitem> <para> - Any generation expressions of copied column definitions will be - copied. By default, new columns will be regular base columns. + Any generation expressions as well as the stored/virtual choice of + copied column definitions will be copied. By default, new columns + will be regular base columns. </para> </listitem> </varlistentry> @@ -907,7 +908,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </varlistentry> <varlistentry id="sql-createtable-parms-generated-stored"> - <term><literal>GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) STORED</literal><indexterm><primary>generated column</primary></indexterm></term> + <term><literal>GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) [ STORED | VIRTUAL ]</literal><indexterm><primary>generated column</primary></indexterm></term> <listitem> <para> This clause creates the column as a <firstterm>generated @@ -916,8 +917,11 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </para> <para> - The keyword <literal>STORED</literal> is required to signify that the - column will be computed on write and will be stored on disk. + When <literal>VIRTUAL</literal> is specified, the column will be + computed when it is read, and it will not occupy any storage. When + <literal>STORED</literal> is specified, the column will be computed on + write and will be stored on disk. <literal>VIRTUAL</literal> is the + default. </para> <para> @@ -2504,9 +2508,9 @@ CREATE TABLE cities_partdef <title>Generated Columns</title> <para> - The option <literal>STORED</literal> is not standard but is also used by - other SQL implementations. The SQL standard does not specify the storage - of generated columns. + The options <literal>STORED</literal> and <literal>VIRTUAL</literal> are + not standard but are also used by other SQL implementations. The SQL + standard does not specify the storage of generated columns. </para> </refsect2> |