the two join variables at both ends: not only trailing rows that need not be
scanned because there cannot be a match on the other side, but initial rows
that will be scanned without possibly having a match.  This allows a more
realistic estimate of startup cost to be made, per recent pgsql-performance
discussion.  In passing, fix a couple of bugs that had crept into
mergejoinscansel: it was not quite up to speed for the task of estimating
descending-order scans, which is a new requirement in 8.3.

the sections below in more detail.

< 	o -Allow commenting of variables in postgresql.conf to restore them
< 	  to defaults
< 	o -Add a GUC variable to control the tablespace for temporary objects
< 	  and sort files
< Monitoring
< ==========
<
< * -Allow server log information to be output as CSV format
< * -Add ability to monitor the use of temporary sort files
< * -Allow user-defined types to accept 'typmod' parameters
<
<   http://archives.postgresql.org/pgsql-hackers/2005-08/msg01142.php
<   http://archives.postgresql.org/pgsql-hackers/2005-09/msg00012.php
<   http://archives.postgresql.org/pgsql-hackers/2006-08/msg00149.php
<
< * -Add Globally/Universally Unique Identifier (GUID/UUID)
<
<   http://archives.postgresql.org/pgsql-patches/2006-09/msg00209.php
<   http://archives.postgresql.org/pgsql-general/2007-01/msg00853.php
<
< * -Support a data type with specific enumerated values (ENUM)
< 	o -Add support for arrays of complex types
< 	o -Make 64-bit version of the MONEY data type
< * -Add ISO day of week format 'ID' to to_char() where Monday = 1
< * -Add a field 'isoyear' to extract(), based on the ISO week
< * -Add RESET SESSION command to reset all session state
< 	o -Make CLUSTER preserve recently-dead tuples per MVCC requirements
< 	o -Add more logical syntax CLUSTER table USING index;
< 	  support current syntax for backward compatibility
< 	o -Allow UPDATE/DELETE WHERE CURRENT OF cursor
< 		o -Add support for MOVE cursors
< 		o -Allow PL/PythonU to return boolean rather than 1/0
< 	o -Allow psql \pset boolean variables to set to fixed values, rather
< 	  than toggle
< 	o -Add -f to pg_dumpall
< Dependency Checking
< ===================
<
< * -Flush cached query plans when the dependent objects change or
<   when new ANALYZE statistics are available
< * -Track dependencies in function bodies and recompile/invalidate
< * -Invalidate prepared queries, like INSERT, when the table definition
<   is altered
<
< * -Allow use of indexes to search for NULLs
< * -Allow the creation of indexes with mixed ascending/descending
<   specifiers
< * -Reduce checkpoint performance degredation by forcing data to disk
<   more evenly
< * -Allow sequential scans to take advantage of other concurrent
<   sequential scans, also called "Synchronised Scanning"
< * -Consider shrinking expired tuples to just their headers
< * -Allow heap reuse of UPDATEd rows if no indexed columns are changed,
<   and old and new versions are on the same heap page
< * -Reduce XID consumption of read-only queries
< 	o -Turn on by default
< 	o -Allow multiple vacuums so large tables do not starve small
< 	  tables
< * -Allow the pg_xlog directory location to be specified during initdb
<   with a symlink back to the /data location
< * -Allow buffered WAL writes and fsync
< * -Allow ORDER BY ... LIMIT # to select high/low value without sort or
<   index using a sequential scan for highest/lowest values
< * -Merge xmin/xmax/cmin/cmax back into three header fields
< 	o -Support a smaller header for short variable-length fields
< * -Move NAMEDATALEN from postgres_ext.h to pg_config_manual.h
< * -Fix problem with excessive logging during SSL disconnection
<
<   http://archives.postgresql.org/pgsql-bugs/2006-12/msg00122.php
<   http://archives.postgresql.org/pgsql-bugs/2007-05/msg00065.php
<
< 	o -Add long file support for binary pg_dump output

checkpoints.

The original coding leaked memory (at least 8K per crosstab_hash call)
because it allowed the hash table to be allocated as a child of
TopMemoryContext and then never freed it.  Fix that by putting the
hash table under per_query_ctx, instead.  Also get rid of use
of a static variable to point to the hash table.  Aside from being
ugly, that would actively do the wrong thing in the case of re-entrant
calls to crosstab_hash, which are at least theoretically possible
since it was expecting the static variable to stay valid across
a SPI_execute call.

copy-editing.

as in unix)

american speling (unlike this commit message).  Per complaint from Mike C. on
bug #3790 and subsequent discussion.

Fix lots of bad markup, bad English, bad explanations.

This commit covers only about half the contrib modules, but I grow weary...

old README file, Bruno Wolff did the bulk of the work, but for some
reason only Hal Snyder was credited here.

Fixes bug #3750

indexable-clauses list for a btree index.  Formerly it just Asserted that
all such clauses were opclauses, but that's no longer true in 8.3.
Per bug #3796 from Matthias Schoeneich.

since we supported standard FOREIGN KEY constraint syntax.  It was
harmless enough just sitting there, but the prospect of having to
document it is surely more work than it's worth.

to the settings used for other platforms.

Hannes Eder

The spi documentation is pretty rudimentary, but it's a start.

the former README files.  Albert Cervera i Areny

namely that \r, \n, \t, \b, \f, \v are dumped as those two-character
representations rather than a backslash and the literal control character.
I had made it do the other to save some code, but this was ill-advised,
because dump files in which these characters appear literally are prone to
newline mangling.  Fortunately, doing it the old way should only cost a few
more lines of code, and not slow down the copy loop materially.
Per bug #3795 from Lou Duchez.

to ensure that the resulting webpages have predictable URLs, instead of
ever-changing numeric IDs.  The new contrib docs were the biggest
offender, but some old stuff had the problem too.  Also, rename a couple
of new contrib sgml files for consistency's sake.

Albert Cervera i Areny

trigger instead of a rule to redirect insertions, use NEW.* notation
where appropriate, some other updates and adjustments.  David Fetter
and Tom Lane

which previously only talked about btree opclasses.

constraint status of copied indexes (bug #3774), as well as various other
small bugs such as failure to pstrdup when needed.  Allow INCLUDING INDEXES
indexes to be merged with identical declared indexes (perhaps not real useful,
but the code is there and having it not apply to LIKE indexes seems pretty
unorthogonal).  Avoid useless work in generateClonedIndexStmt().  Undo some
poorly chosen API changes, and put a couple of routines in modules that seem
to be better places for them.

lookup of the well-known OID of textout().

implicit loading of modules, thereby breaking Safe rules.
We compile and call a tiny perl function on trusted interpreter init, after which
the problem does not occur.

but no database changes have been made since the last CommandCounterIncrement.
This should result in a significant improvement in the number of "commands"
that can typically be performed within a transaction before hitting the 2^32
CommandId size limit.  In particular this buys back (and more) the possible
adverse consequences of my previous patch to fix plan caching behavior.

The implementation requires tracking whether the current CommandCounter
value has been "used" to mark any tuples.  CommandCounter values stored into
snapshots are presumed not to be used for this purpose.  This requires some
small executor changes, since the executor used to conflate the curcid of
the snapshot it was using with the command ID to mark output tuples with.
Separating these concepts allows some small simplifications in executor APIs.

Something for the TODO list: look into having CommandCounterIncrement not do
AcceptInvalidationMessages.  It seems fairly bogus to be doing it there,
but exactly where to do it instead isn't clear, and I'm disinclined to mess
with asynchronous behavior during late beta.