By using curly braces, the template had specified that one of
"NOT DEFERRABLE", "INITIALLY IMMEDIATE", or "INITIALLY DEFERRED"
was required on any CREATE TRIGGER statement, which is not
accurate.  Change to square brackets makes that optional.

Backpatch to 9.1, where the error was introduced.

To avoid divergent names on related pages, avoid ambiguities, and
reduce translation work a little.

This check was overlooked when we added function execute permissions to the
system years ago.  For an ordinary trigger function it's not a big deal,
since trigger functions execute with the permissions of the table owner,
so they couldn't do anything the user issuing the CREATE TRIGGER couldn't
have done anyway.  However, if a trigger function is SECURITY DEFINER,
that is not the case.  The lack of checking would allow another user to
install it on his own table and then invoke it with, essentially, forged
input data; which the trigger function is unlikely to realize, so it might
do something undesirable, for instance insert false entries in an audit log
table.

Reported by Dinesh Kumar, patch by Robert Haas

Security: CVE-2012-0866

There is what may actually be a mistake in our markup.  The problem is
in a situation like

<para>
 <command>FOO</command> is ...

there is strictly speaking a line break before "FOO".  In the HTML
output, this does not appear to be a problem, but in the man page
output, this shows up, so you get double blank lines at odd places.

So far, we have attempted to work around this with an XSL hack, but
that causes other problems, such as creating run-ins in places like

<acronym>SQL</acronym> <command>COPY</command>

So fix the problem properly by removing the extra whitespace.  I only
fixed the problems that affect the man page output, not all the
places.

Per suggestions from Thom Brown and Robert Haas.

The grammar requires a specific ordering of the clauses, but the
documentation showed a different order.  This error was introduced in
commit b47953f9, which merged the CREATE
CONSTRAINT TRIGGER documentation into the CREATE TRIGGER page.  There is
no code bug AFAICS.

This patch adds the SQL-standard concept of an INSTEAD OF trigger, which
is fired instead of performing a physical insert/update/delete.  The
trigger function is passed the entire old and/or new rows of the view,
and must figure out what to do to the underlying tables to implement
the update.  So this feature can be used to implement updatable views
using trigger programming style rather than rule hacking.

In passing, this patch corrects the names of some columns in the
information_schema.triggers view.  It seems the SQL committee renamed
them somewhere between SQL:99 and SQL:2003.

Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.

The endterm attribute is mainly useful when the toolchain does not support
automatic link target text generation for a particular situation.  In  the
past, this was required by the man page tools for all reference page links,
but that is no longer the case, and it now actually gets in the way of
proper automatic link text generation.  The only remaining use cases are
currently xrefs to refsects.

checked to determine whether the trigger should be fired.

For BEFORE triggers this is mostly a matter of spec compliance; but for AFTER
triggers it can provide a noticeable performance improvement, since queuing of
a deferred trigger event and re-fetching of the row(s) at end of statement can
be short-circuited if the trigger does not need to be fired.

Takahiro Itagaki, reviewed by KaiGai Kohei.

are named in the UPDATE's SET list.

Note: the schema of pg_trigger has not actually changed; we've just started
to use a column that was there all along.  catversion bumped anyway so that
this commit is included in the history of potentially interesting changes
to system catalog contents.

Itagaki Takahiro

another section if required by the platform (instead of the old way of
building them in section "l" and always transforming them to the
platform-specific section).

This speeds up the installation on common platforms, and it avoids some
funny business with the man page tools and build process.

Standard English uses "may", "can", and "might" in different ways:

        may - permission, "You may borrow my rake."

        can - ability, "I can lift that log."

        might - possibility, "It might rain today."

Unfortunately, in conversational English, their use is often mixed, as
in, "You may use this variable to do X", when in fact, "can" is a better
choice.  Similarly, "It may crash" is better stated, "It might crash".

Standard English uses "may", "can", and "might" in different ways:

        may - permission, "You may borrow my rake."

        can - ability, "I can lift that log."

        might - possibility, "It might rain today."

Unfortunately, in conversational English, their use is often mixed, as
in, "You may use this variable to do X", when in fact, "can" is a better
choice.  Similarly, "It may crash" is better stated, "It might crash".

integrity actions.

Stephan Szabo

is used as if it were the latest (and/or still valid) SQL standard.
SQL:2003 is used in its place. Patch from Simon Riggs.

by Troels Arvin, Simon Riggs, Elein Mustain

Make spelling of SQL standard names uniform.

$Header: -> $PostgreSQL Changes ...

discussion.  (Still have some work to do editing the remainder.)

vague cross-references with real links.

including:

- replacing all the appropriate usages of <citetitle>PostgreSQL
...</citetitle> with &cite-user;, &cite-admin;, and so on

- fix an omission in the EXECUTE documentation

- add some more text to the EXPLAIN documentation

- improve the PL/PgSQL RETURN NEXT documentation (more work to do here)

- minor markup fixes


Neil Conway

Neil Conway

-hackers a couple days ago.

Notes/caveats:

        - added regression tests for the new functionality, all
          regression tests pass on my machine

        - added pg_dump support

        - updated PL/PgSQL to support per-statement triggers; didn't
          look at the other procedural languages.

        - there's (even) more code duplication in trigger.c than there
          was previously. Any suggestions on how to refactor the
          ExecXXXTriggers() functions to reuse more code would be
          welcome -- I took a brief look at it, but couldn't see an
          easy way to do it (there are several subtly-different
          versions of the code in question)

        - updated the documentation. I also took the liberty of
          removing a big chunk of duplicated syntax documentation in
          the Programmer's Guide on triggers, and moving that
          information to the CREATE TRIGGER reference page.

        - I also included some spelling fixes and similar small
          cleanups I noticed while making the changes. If you'd like
          me to split those into a separate patch, let me know.

Neil Conway

with OPAQUE.  CREATE LANGUAGE, CREATE TRIGGER, and CREATE TYPE will all
accept references to functions declared with OPAQUE --- but they will
issue a NOTICE, and will modify the function entries in pg_proc to have
the preferred type-safe argument or result types instead of OPAQUE.
Per recent pghackers discussions.

with OPAQUE, as per recent pghackers discussion.  I still want to do some
more work on the 'cstring' pseudo-type, but I'm going to commit the bulk
of the changes now before the tree starts shifting under me ...

no objections.

Joe Conway

 capabilities of specifying time zones as intervals per SQL9x.
Put refentrytitle contents on the same line as the tag.
 Otherwise, leading whitespace is propagated into the product, which
 (at least) messes up the ToC layout.
Remove (some) docinfo tags containing dates. Best to omit if the dates
 are not accurate; maybe use CVS dates instead or leave them out.