threshold for tuple length.  On 4-byte-MAXALIGN machines, the toast code
creates tuples that have t_len exactly TOAST_TUPLE_THRESHOLD ... but this
number is not itself maxaligned, so if heap_insert maxaligns t_len before
comparing to TOAST_TUPLE_THRESHOLD, it'll uselessly recurse back to
tuptoaster.c, wasting cycles.  (It turns out that this does not happen on
8-byte-MAXALIGN machines, because for them the outer MAXALIGN in the
TOAST_MAX_CHUNK_SIZE macro reduces TOAST_MAX_CHUNK_SIZE so that toast tuples
will be less than TOAST_TUPLE_THRESHOLD in size.  That MAXALIGN is really
incorrect, but we can't remove it now, see below.)  There isn't any particular
value in maxaligning before comparing to the thresholds, so just don't do
that, which saves a small number of cycles in itself.

These numbers should be rejiggered to minimize wasted space on toast-relation
pages, but we can't do that in the back branches because changing
TOAST_MAX_CHUNK_SIZE would force an initdb (by changing the contents of toast
tables).  We can move the toast decision thresholds a bit, though, which is
what this patch effectively does.

Thanks to Pavan Deolasee for discovering the unintended recursion.

Back-patch into 8.2, but not further, pending more testing.  (HEAD is about
to get a further patch modifying the thresholds, so it won't help much
for testing this form of the patch.)

>
> * Allow custom variable classes that can restrict who can set the values
>
>   http://archives.postgresql.org/pgsql-hackers/2006-11/msg00911.php
>

Backpatch to 8.2.X.

  errhint("Consider using VACUUM FULL on this relation or increasing the configuration parameter \"max_fsm_pages\".")));

* Allow sequential scans to take advantage of other concurrent
  sequential scans, also called "Synchronised Scanning"

>
> 	o Add \# to list command history like \s, but with line numbers
>
> 	  http://archives.postgresql.org/pgsql-hackers/2006-12/msg00255.php
>

* Allow sequential scans to take advantage of other concurrent
  sequential scans, also called "Synchronised Scanning"
>   http://archives.postgresql.org/pgsql-patches/2006-12/msg00076.php
>   http://archives.postgresql.org/pgsql-hackers/2006-12/msg00408.php

	gmake -C src/bin install

does install a few server-only binaries.

> 	  o Allow recovery.conf to allow the same syntax as
> 	    postgresql.conf, including quoting
>
> 	    http://archives.postgresql.org/pgsql-hackers/2006-12/msg00497.php

observe the xmloption.

Reorganize the representation of the XML option in the parse tree and the
API to make it easier to manage and understand.

Add regression tests for parsing back XML expressions.

are both used.

Albe Laurenz

* Reduce checkpoint performance degredation by forcing data to disk
  more evenly

>   http://archives.postgresql.org/pgsql-patches/2006-12/msg00104.php

* Allow sequential scans to take advantage of other concurrent
  sequential scans, also called "Synchronised Scanning"
>
>   http://archives.postgresql.org/pgsql-hackers/2006-12/msg00784.php

> * Reduce checkpoint performance degredation by forcing data to disk
>   more evenly
>
>   http://archives.postgresql.org/pgsql-hackers/2006-12/msg00337.php
>   http://archives.postgresql.org/pgsql-hackers/2007-01/msg00079.php

                o Fix RENAME to work on variables other than OLD/NEW
> 		  http://archives.postgresql.org/pgsql-hackers/2007-01/msg01587.php

generated solution files for what to install, instead of blindly copying
everything as it previously did. With the previous quick-n-dirty
version, it would copy old DLLs if you reconfigured in a way that didn't
include subprojects like a PL for example.

Magnus Hagander.

Windows. Per Magnus Hagander, this is not recommended.

> 	o Allow column display reordering by recording a display,
> 	  storage, and permanent id for every column?
>
> 	  http://archives.postgresql.org/pgsql-hackers/2006-12/msg00782.php
>

Security: CVE-2007-0555, CVE-2007-0556

made query plan.  Use of ALTER COLUMN TYPE creates a hazard for cached
query plans: they could contain Vars that claim a column has a different
type than it now has.  Fix this by checking during plan startup that Vars
at relation scan level match the current relation tuple descriptor.  Since
at that point we already have at least AccessShareLock, we can be sure the
column type will not change underneath us later in the query.  However,
since a backend's locks do not conflict against itself, there is still a
hole for an attacker to exploit: he could try to execute ALTER COLUMN TYPE
while a query is in progress in the current backend.  Seal that hole by
rejecting ALTER TABLE whenever the target relation is already open in
the current backend.

This is a significant security hole: not only can one trivially crash the
backend, but with appropriate misuse of pass-by-reference datatypes it is
possible to read out arbitrary locations in the server process's memory,
which could allow retrieving database content the user should not be able
to see.  Our thanks to Jeff Trout for the initial report.

Security: CVE-2007-0556

we should check that the function code returns the claimed result datatype
every time we parse the function for execution.  Formerly, for simple
scalar result types we assumed the creation-time check was sufficient, but
this fails if the function selects from a table that's been redefined since
then, and even more obviously fails if check_function_bodies had been OFF.

This is a significant security hole: not only can one trivially crash the
backend, but with appropriate misuse of pass-by-reference datatypes it is
possible to read out arbitrary locations in the server process's memory,
which could allow retrieving database content the user should not be able
to see.  Our thanks to Jeff Trout for the initial report.

Security: CVE-2007-0555

"can't" -> "cannot" section.

for the recent may/might cleanup.

shared hardware section, and mention DRBD as a popular solution.

recent may/might cleanup, in the hopes that this will unbreak the
buildfarm. Per report from Stefan Kaltenbrunner.

an error will be thrown correctly if the variable is of a NOT NULL domain.
Report and almost-correct fix from Sergiy Vyshnevetskiy (bug #2948).

        o Add long file support for binary pg_dump output
>
> 	  http://archives.postgresql.org/pgsql-hackers/2006-12/msg00551.php

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".

behavior has changed.

Daojing.Zhou

<   http://archives.postgresql.org/pgsql-hackers/2006-12/msg00564.php
>   http://archives.postgresql.org/pgsql-hackers/2006-12/msg00568.php
>

>
> * Tighten function permission checks
>
>   http://archives.postgresql.org/pgsql-hackers/2006-12/msg00564.php
>

>
> * Tighten trigger permission checks
>
>   http://archives.postgresql.org/pgsql-hackers/2006-12/msg00564.php
>