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Support writing "CREATE/ALTER TABLE ... SET STORAGE DEFAULT".

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We already allow explicitly writing DEFAULT for SET COMPRESSION,
so it seems a bit inflexible and non-orthogonal to not have it
for STORAGE.

Aleksander Alekseev

Discussion: https://postgr.es/m/CAJ7c6TMX9ui+6y3TQFaXJYVpZyBukvqhQbVDJ8OUokeLRhtnpA@mail.gmail.com
This commit is contained in:
Tom Lane
2022-11-10 18:20:49 -05:00
parent b158e0b1b1
commit b9424d014e
9 changed files with 31 additions and 22 deletions
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22
doc/src/sgml/ref/alter_table.sgml
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@@ -53,7 +53,7 @@ ALTER TABLE [ IF EXISTS ] <replaceable class="parameter">name</replaceable>
ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET STATISTICS <replaceable class="parameter">integer</replaceable>
ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET ( <replaceable class="parameter">attribute_option</replaceable> = <replaceable class="parameter">value</replaceable> [, ... ] )
ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> RESET ( <replaceable class="parameter">attribute_option</replaceable> [, ... ] )
ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN }
ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN | DEFAULT }
ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET COMPRESSION <replaceable class="parameter">compression_method</replaceable>
ADD <replaceable class="parameter">table_constraint</replaceable> [ NOT VALID ]
ADD <replaceable class="parameter">table_constraint_using_index</replaceable>
@@ -367,7 +367,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<varlistentry>
<term>
<literal>SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN }</literal>
<literal>SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN | DEFAULT }</literal>
<indexterm>
<primary>TOAST</primary>
<secondary>per-column storage settings</secondary>
@@ -376,20 +376,24 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<listitem>
<para>
This form sets the storage mode for a column. This controls whether this
column is held inline or in a secondary <acronym>TOAST</acronym> table, and
whether the data
column is held inline or in a secondary <acronym>TOAST</acronym> table,
and whether the data
should be compressed or not. <literal>PLAIN</literal> must be used
for fixed-length values such as <type>integer</type> and is
inline, uncompressed. <literal>MAIN</literal> is for inline,
compressible data. <literal>EXTERNAL</literal> is for external,
uncompressed data, and <literal>EXTENDED</literal> is for external,
compressed data. <literal>EXTENDED</literal> is the default for most
data types that support non-<literal>PLAIN</literal> storage.
compressed data.
Writing <literal>DEFAULT</literal> sets the storage mode to the default
mode for the column's data type. <literal>EXTENDED</literal> is the
default for most data types that support non-<literal>PLAIN</literal>
storage.
Use of <literal>EXTERNAL</literal> will make substring operations on
very large <type>text</type> and <type>bytea</type> values run faster,
at the penalty of increased storage space. Note that
<literal>SET STORAGE</literal> doesn't itself change anything in the table,
it just sets the strategy to be pursued during future table updates.
at the penalty of increased storage space.
Note that <literal>ALTER TABLE ... SET STORAGE</literal> doesn't itself
change anything in the table; it just sets the strategy to be pursued
during future table updates.
See <xref linkend="storage-toast"/> for more information.
</para>
</listitem>