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Revert CREATE INDEX ... INCLUDING ...

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690c543550 - unstable test output
386e3d7609 - patch itself
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Teodor Sigaev
2016-04-08 21:52:13 +03:00
parent 35e2e357cb
commit 8b99edefca
68 changed files with 256 additions and 1321 deletions
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41
doc/src/sgml/ref/create_index.sgml
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@@ -23,7 +23,6 @@ PostgreSQL documentation
<synopsis>
CREATE [ UNIQUE ] INDEX [ CONCURRENTLY ] [ [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> ] ON <replaceable class="parameter">table_name</replaceable> [ USING <replaceable class="parameter">method</replaceable> ]
( { <replaceable class="parameter">column_name</replaceable> | ( <replaceable class="parameter">expression</replaceable> ) } [ COLLATE <replaceable class="parameter">collation</replaceable> ] [ <replaceable class="parameter">opclass</replaceable> ] [ ASC | DESC ] [ NULLS { FIRST | LAST } ] [, ...] )
[ INCLUDING ( <replaceable class="parameter">column_name</replaceable> [, ...] ) ]
[ WITH ( <replaceable class="PARAMETER">storage_parameter</replaceable> = <replaceable class="PARAMETER">value</replaceable> [, ... ] ) ]
[ TABLESPACE <replaceable class="parameter">tablespace_name</replaceable> ]
[ WHERE <replaceable class="parameter">predicate</replaceable> ]
@@ -139,35 +138,6 @@ CREATE [ UNIQUE ] INDEX [ CONCURRENTLY ] [ [ IF NOT EXISTS ] <replaceable class=
</listitem>
</varlistentry>
<varlistentry>
<term><literal>INCLUDING</literal></term>
<listitem>
<para>
An optional <literal>INCLUDING</> clause allows a list of columns to be
specified which will be included in the index, in the non-key portion of
the index. Columns which are part of this clause cannot also exist in
the key columns portion of the index, and vice versa. The
<literal>INCLUDING</> columns exist solely to allow more queries to
benefit from <firstterm>index-only scans</> by including certain
columns in the index, the value of which would otherwise have to be
obtained by reading
the table's heap. Having these columns in the <literal>INCLUDING</>
clause in some cases allows <productname>PostgreSQL</> to skip the heap
read completely. This also allows <literal>UNIQUE</> indexes to be
defined on one set of columns, which can include another set of column
in the <literal>INCLUDING</> clause, on which the uniqueness is not
enforced upon. It's the same with other constraints (PRIMARY KEY and
EXCLUDE). This can also can be used for non-unique indexes as any
columns which are not required for the searching or ordering of records
can be included in the <literal>INCLUDING</> clause, which can slightly
reduce the size of the index, due to storing included attributes only
in leaf index pages. Currently, only the B-tree access method supports
this feature. Expressions as included columns are not supported since
they cannot be used in index-only scan.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><replaceable class="parameter">name</replaceable></term>
<listitem>
@@ -629,22 +599,13 @@ Indexes:
<title>Examples</title>
<para>
To create a unique B-tree index on the column <literal>title</literal> in
To create a B-tree index on the column <literal>title</literal> in
the table <literal>films</literal>:
<programlisting>
CREATE UNIQUE INDEX title_idx ON films (title);
</programlisting>
</para>
<para>
To create a unique B-tree index on the column <literal>title</literal>
and included columns <literal>director</literal> and <literal>rating</literal>
in the table <literal>films</literal>:
<programlisting>
CREATE UNIQUE INDEX title_idx ON films (title) INCLUDING (director, rating);
</programlisting>
</para>
<para>
To create an index on the expression <literal>lower(title)</>,
allowing efficient case-insensitive searches: