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Support window functions a la SQL:2008.

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Hitoshi Harada, with some kibitzing from Heikki and Tom.
This commit is contained in:
Tom Lane
2008-12-28 18:54:01 +00:00
parent 38e9348282
commit 95b07bc7f5
92 changed files with 6720 additions and 321 deletions
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10
doc/src/sgml/query.sgml
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@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/query.sgml,v 1.50 2007/02/01 00:28:17 momjian Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/query.sgml,v 1.51 2008/12/28 18:53:54 tgl Exp $ -->
<chapter id="tutorial-sql">
<title>The <acronym>SQL</acronym> Language</title>
@ -621,7 +621,7 @@ SELECT W1.city, W1.temp_lo AS low, W1.temp_hi AS high,
San Francisco | 43 | 57 | San Francisco | 46 | 50
Hayward | 37 | 54 | San Francisco | 46 | 50
(2 rows)
</programlisting>
</programlisting>
Here we have relabeled the weather table as <literal>W1</> and
<literal>W2</> to be able to distinguish the left and right side
@ -651,9 +651,9 @@ SELECT *
<indexterm><primary>min</primary></indexterm>
<indexterm><primary>sum</primary></indexterm>
Like most other relational database products,
Like most other relational database products,
<productname>PostgreSQL</productname> supports
aggregate functions.
<firstterm>aggregate functions</>.
An aggregate function computes a single result from multiple input rows.
For example, there are aggregates to compute the
<function>count</function>, <function>sum</function>,
@ -815,7 +815,7 @@ SELECT city, max(temp_lo)
<para>
You can update existing rows using the
<command>UPDATE</command> command.
<command>UPDATE</command> command.
Suppose you discover the temperature readings are
all off by 2 degrees after November 28. You can correct the
data as follows: