diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index becc8720bca0fe29ca6bf75255a8ab215dd2242a..6980dc47752fa4d7c30533066b5810526b69ea71 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -1,5 +1,5 @@
<!--
-$PostgreSQL: pgsql/doc/src/sgml/advanced.sgml,v 1.40 2004/03/30 22:08:50 momjian Exp $
+$PostgreSQL: pgsql/doc/src/sgml/advanced.sgml,v 1.41 2004/03/31 16:20:53 momjian Exp $
-->
<chapter id="tutorial-advanced">
@@ -65,25 +65,11 @@ SELECT * FROM myview;
<para>
Views can be used in almost any place a real table can be used.
- Building views upon other views is not uncommon. You may cut down
- on the difficulty of building complex queries by constructing them
- in smaller, easier-to-verify pieces, using views. Views may be
- used to reveal specific table columns to users that legitimately
- need access to some of the data, but who shouldn't be able to look
- at the whole table.
+ Building views upon other views is not uncommon.
</para>
-
- <para>
- Views differ from <quote> real tables </quote> in that they are
- not, by default, updatable. If they join together several tables,
- it may be troublesome to update certain columns since the
- <emphasis>real</emphasis> update that must take place requires
- identifying the relevant rows in the source tables. This is
- discussed further in <xref linkend="rules-views-update">.
- </para>
-
</sect1>
+
<sect1 id="tutorial-fk">
<title>Foreign Keys</title>
@@ -401,169 +387,6 @@ SELECT name, altitude
</para>
</sect1>
- <sect1 id="tutorial-storedprocs">
- <title> Stored Procedures </title>
-
- <indexterm zone="tutorial-storedprocs">
- <primary>stored procedures</primary>
- </indexterm>
-
- <para> Stored procedures are code that runs inside the database
- system. Numerous languages may be used to implement functions and
- procedures; most built-in code is implemented in C. The
- <quote>basic</quote> loadable procedural language for
- <productname>PostgreSQL</productname> is <xref linkend="plpgsql">.
- Numerous other languages may also be used, including <xref
- linkend="plperl">, <xref linkend="pltcl">, and <xref
- linkend="plpython">.
- </para>
-
- <para> There are several ways that stored procedures are really
- helpful:
-
- <itemizedlist>
-
- <listitem><para> To centralize data validation code into the
- database </para>
-
- <para> Your system may use client software written in several
- languages, perhaps with a <quote>web application</quote>
- implemented in PHP, a <quote>server application</quote> implemented
- in Java, and a <quote> report writer</quote> implemented in Perl.
- In the absence of stored procedures, you will likely find that data
- validation code must be implemented multiple times, in multiple
- languages, once for each application.</para>
-
- <para> By implementing data validation in stored procedures,
- running in the database, it can behave uniformly for all these
- systems, and you do not need to worry about synchronizing
- validation procedures across the languages.</para>
-
- </listitem>
-
- <listitem><para> Reducing round trips between client and server
- </para>
-
- <para>A stored procedure may submit multiple queries, looking up
- information and adding in links to additional tables. This takes
- place without requiring that the client submit multiple queries,
- and without requiring any added network traffic.
- </para>
-
- <para> As a matter of course, the queries share a single
- transaction context, and there may also be savings in the
- evaluation of query plans, that will be similar between invocations
- of a given stored procedure. </para></listitem>
-
- <listitem><para> To simplify queries. </para>
-
- <para> For instance, if you are commonly checking the TLD on domain
- names, you might create a stored procedure for this purpose, and so
- be able to use queries such as <command> select domain, tld(domain)
- from domains; </command> instead of having to put verbose code
- using <function>substr()</function> into each query.
- </para>
-
- <para> It is particularly convenient to use scripting languages
- like Perl, Tcl, and Python to <quote>grovel through strings</quote>
- since they are designed for <quote>text processing.</quote></para>
-
- <para> The binding to the R statistical language allows
- implementing complex statistical queries inside the database,
- instead of having to draw the data out.
- </listitem>
-
- <listitem><para> Increasing the level of abstraction</para>
-
- <para> If data is accessed exclusively through stored procedures,
- then the structures of tables may be changed without there needing
- to be any visible change in the API used by programmers. In some
- systems, users are <emphasis>only</emphasis> allowed access to
- stored procedures to update data, and cannot do direct updates to
- tables.
- </para>
-
- </listitem>
-
- </itemizedlist>
- </para>
-
- <para> These benefits build on one another: careful use of stored
- procedures can simultaneously improve reliability and performance,
- whilst simplifying database access code and improving portability
- across client platforms and languages. For instance, consider that
- a stored procedure can cheaply query tables in the database to
- validate the correctness of data provided as input. </para>
-
- <para> Instead of requiring a whole series of queries to create an
- object, and to look up parent/subsidiary objects to link it to, a
- stored procedure can do all of this efficiently in the database
- server, improving performance, and eliminating whole classes of
- errors. </para>
-
- </sect1>
-
- <sect1 id="tutorial-triggers">
- <title> Triggers </title>
-
- <indexterm zone="tutorial-triggers">
- <primary>triggers</primary>
- </indexterm>
-
- <para> Triggers allow running a function either before or after
- update (<command>INSERT</command>, <command>DELETE</command>,
- <command>UPDATE</command>) operations, which can allow you to do
- some very clever things. </para>
-
- <itemizedlist>
-
- <listitem><para> Data Validation </para>
-
- <para> Instead of explicitly coding validation checks as part of a
- stored procedure, they may be introduced as <command>BEFORE</command>
- triggers. The trigger function checks the input values, raising an
- exception if it finds invalid input.</para>
-
- <para> Note that this is how foreign key checks are implemented in
- <productname>PostgreSQL</productname>; when you define a foreign
- key, you will see a message similar to the following:
-<screen>
-NOTICE: CREATE TABLE will create implicit trigger(s) for FOREIGN KEY check(s)
-</screen></para>
-
- <para> In some cases, it may be appropriate for a trigger function
- to insert data in order to <emphasis>make</emphasis> the input valid. For
- instance, if a newly created object needs a status code in a status
- table, the trigger might automatically do that.</para>
- </listitem>
-
- <listitem><para> Audit logs </para>
-
- <para> One may use <command>AFTER</command> triggers to monitor updates to
- vital tables, and <command>INSERT</command> entries into log tables to
- provide a more permanent record of those updates. </para>
- </listitem>
-
- <listitem><para> Replication </para>
-
- <para> The <application>RServ</application> replication system uses
- <command>AFTER</command> triggers to track which rows have changed on the
- <quote>master</quote> system and therefore need to be copied over to
- <quote>slave</quote> systems.</para>
-
- <para> <command>
- CREATE TRIGGER "_rserv_trigger_t_" AFTER INSERT OR DELETE OR UPDATE ON "my_table"
- FOR EACH ROW EXECUTE PROCEDURE "_rserv_log_" ('10');
- </command></para>
- </listitem>
-
- </itemizedlist>
-
- <para> Notice that there are strong parallels between what can be
- accomplished using triggers and stored procedures, particularly in
- regards to data validation. </para>
-
- </sect1>
<sect1 id="tutorial-conclusion">
<title>Conclusion</title>
diff --git a/doc/src/sgml/datetime.sgml b/doc/src/sgml/datetime.sgml
index 026fb5d553f62a32dd8d18d6990827dca34d941c..dd5d371e19d4d1b91664736cf8ccc95273d01397 100644
--- a/doc/src/sgml/datetime.sgml
+++ b/doc/src/sgml/datetime.sgml
@@ -1,5 +1,5 @@
<!--
-$PostgreSQL: pgsql/doc/src/sgml/datetime.sgml,v 2.40 2004/03/30 21:58:20 momjian Exp $
+$PostgreSQL: pgsql/doc/src/sgml/datetime.sgml,v 2.41 2004/03/31 16:20:53 momjian Exp $
-->
<appendix id="datetime-appendix">
@@ -11,8 +11,8 @@ $PostgreSQL: pgsql/doc/src/sgml/datetime.sgml,v 2.40 2004/03/30 21:58:20 momjian
strings, and are broken up into distinct fields with a preliminary
determination of what kind of information may be in the
field. Each field is interpreted and either assigned a numeric
- value, ignored, or rejected.</para>
- <para> The parser contains internal lookup tables for all textual fields,
+ value, ignored, or rejected.
+ The parser contains internal lookup tables for all textual fields,
including months, days of the week, and time
zones.
</para>
@@ -1056,21 +1056,21 @@ $PostgreSQL: pgsql/doc/src/sgml/datetime.sgml,v 2.40 2004/03/30 21:58:20 momjian
years.
</para>
- <para> The papal bull of February 1582 decreed that 10 days should
- be dropped from October 1582 so that 15 October should follow
- immediately after 4 October.</para>
-
- <para> This was observed in Italy, Poland, Portugal, and Spain.
- Other Catholic countries followed shortly after, but Protestant
- countries were reluctant to change, and the Greek orthodox countries
- didn't change until the start of the 20th century.</para>
+ <para>
+ The papal bull of February 1582 decreed that 10 days should be dropped
+ from October 1582 so that 15 October should follow immediately after
+ 4 October.
+ This was observed in Italy, Poland, Portugal, and Spain. Other Catholic
+ countries followed shortly after, but Protestant countries were
+ reluctant to change, and the Greek orthodox countries didn't change
+ until the start of the 20th century.
- <para> The reform was observed by Great Britain and Dominions
- (including what is now the USA) in 1752. Thus 2 September 1752 was
- followed by 14 September 1752.</para>
+ The reform was observed by Great Britain and Dominions (including what is
+ now the USA) in 1752.
+ Thus 2 September 1752 was followed by 14 September 1752.
- <para> This is why Unix systems have the <command>cal</command>
- program produce the following:
+ This is why Unix systems have the <command>cal</command> program
+ produce the following:
<screen>
$ <userinput>cal 9 1752</userinput>
@@ -1094,24 +1094,19 @@ $ <userinput>cal 9 1752</userinput>
</para>
</note>
- <para> Different calendars have been developed in various parts of
- the world, many predating the Gregorian system.</para>
+ <para>
+ Different calendars have been developed in various parts of the
+ world, many predating the Gregorian system.
- <para> For example, the beginnings of the Chinese calendar can be
- traced back to the 14th century BC. Legend has it that the Emperor
- Huangdi invented the calendar in 2637 BC.</para>
+ For example,
+ the beginnings of the Chinese calendar can be traced back to the 14th
+ century BC. Legend has it that the Emperor Huangdi invented the
+ calendar in 2637 BC.
- <para> The People's Republic of China uses the Gregorian calendar
- for civil purposes. The Chinese calendar is used for determining
- festivals.
+ The People's Republic of China uses the Gregorian calendar
+ for civil purposes. The Chinese calendar is used for determining
+ festivals.
</para>
-
- <para> If you are interested in this sort of thing, <citation>
- Calendrical Calculations: The Millennium Edition </citation> by by
- Edward M. Reingold and Nachum Dershowitz is an excellent reference,
- describing some 25 calendars, and providing software for displaying
- them and converting between them.</para>
-
</sect1>
</appendix>