This is mostly about grammar, style, and presentation, though I did find
a few small factual errors.

We already mentioned xid wraparound.

Per gripe from Fujii Masao, though this is not exactly his proposed patch.
Categorize as DEVELOPER_OPTIONS and set context PGC_SIGHUP, as per Fujii,
but set the default to LOG because higher values aren't really sensible
(see the code for trace_recovery()).  Fix the documentation to agree with
the code and to try to explain what the variable actually does.  Get rid
of no-op calls trace_recovery(LOG), which accomplish nothing except to
demonstrate that this option confuses even its author.

Block elements with verbatim formatting (literallayout, programlisting,
screen, synopsis) should be aligned at column 0 independent of the surrounding
SGML, because whitespace is significant, and indenting them creates erratic
whitespace in the output.  The CSS stylesheets already take care of indenting
the output.

Assorted markup improvements to go along with it.

I've added a quote_all_identifiers GUC which affects the behavior
of the backend, and a --quote-all-identifiers argument to pg_dump
and pg_dumpall which sets the GUC and also affects the quoting done
internally by those applications.

Design by Tom Lane; review by Alex Hunsaker; in response to bug #5488
filed by Hartmut Goebel.

Normally, we automatically restart after a backend crash, but in some
cases when PostgreSQL is invoked by clusterware it may be desirable to
suppress this behavior, so we provide an option which does this.
Since no existing GUC group quite fits, create a new group called
"error handling options" for this and the previously undocumented GUC
exit_on_error, which is now documented.

Review by Fujii Masao.

This change should be publicized to driver maintainers at once and
release-noted as an incompatibility with previous releases.

log files created by the syslogger process.

In passing, make unix_file_permissions display its value in octal, same
as log_file_mode now does.

Martin Pihlak

wal_keep_segments does not take effect during recovery.

Fujii Masao

libpq support.

Per extensive discussion on pgsql-hackers.  We are deliberately not
back-patching this even though the behavior of 8.3 and 8.4 is
unquestionably broken, for fear of breaking existing users of this
parameter.  This incompatibility should be release-noted.

MacOS X uses TCP_KEEPALIVE rather than TCP_KEEPIDLE for this purpose.

Thanks to Fujii Masao for the review.

to have different values in different processes of the primary server.
Also put it into the "Streaming Replication" GUC category; it doesn't belong
in "Standby Servers" because you use it on the master not the standby.
In passing also correct guc.c's idea of wal_keep_segments' category.

max_standby_streaming_delay, and revise the implementation to avoid assuming
that timestamps found in WAL records can meaningfully be compared to clock
time on the standby server.  Instead, the delay limits are compared to the
elapsed time since we last obtained a new WAL segment from archive or since
we were last "caught up" to WAL data arriving via streaming replication.
This avoids problems with clock skew between primary and standby, as well
as other corner cases that the original coding would misbehave in, such
as the primary server having significant idle time between transactions.
Per my complaint some time ago and considerable ensuing discussion.

Do some desultory editing on the hot standby documentation, too.

between words).

lowercase the library names, unless double-quoted.

Report from Thom Brown

Document that synchronous_commit can lose transactions in a db crash,
not just a OS crash.

stat(2) field st_size returns bytes not kilobytes.
Bug found during recent performance tuning for PostgreSQL user.

description for vacuum_defer_cleanup_age to the correct category.
Sections in postgresql.conf are also sorted in the same order with docs.

Per gripe by Fujii Masao, suggestion by Heikki Linnakangas, and patch by me.

them off.

Josh Berkus, with slight wording changes by me.

chains, do assorted wordsmithing.

now used for other things than just ident authentication.

Noted by Stephen Frost

form a hierarchy. Per Simon's suggestion.

the PITR documentation to mention that you need to set wal_level to
'archive' or 'hot_standby', to enable WAL archiving. Per Simon's request.

for all other parameters where the default is expressed in a different unit.

MaxStandbyDelay.  Use the GUC units mechanism for the value, and choose more
appropriate timestamp functions for performing tests with it.  Make the
ps_activity manipulation in ResolveRecoveryConflictWithVirtualXIDs have
behavior similar to ps_activity code elsewhere, notably not updating the
display when update_process_title is off and not truncating the display
contents at an arbitrarily-chosen length.  Improve the docs to be explicit
about what MaxStandbyDelay actually measures, viz the difference between
primary and standby servers' clocks, and the possible hazards if their clocks
aren't in sync.

confusion with streaming-replication settings.  Also, change its default
value to "off", because of concern about executing new and poorly-tested
code during ordinary non-replicating operation.  Per discussion.

In passing do some minor editing of related documentation.

archival or hot standby should be WAL-logged, instead of deducing that from
other options like archive_mode. This replaces recovery_connections GUC in
the primary, where it now has no effect, but it's still used in the standby
to enable/disable hot standby.

Remove the WAL-logging of "unlogged operations", like creating an index
without WAL-logging and fsyncing it at the end. Instead, we keep a copy of
the wal_mode setting and the settings that affect how much shared memory a
hot standby server needs to track master transactions (max_connections,
max_prepared_xacts, max_locks_per_xact) in pg_control. Whenever the settings
change, at server restart, write a WAL record noting the new settings and
update pg_control. This allows us to notice the change in those settings in
the standby at the right moment, they used to be included in checkpoint
records, but that meant that a changed value was not reflected in the
standby until the first checkpoint after the change.

Bump PG_CONTROL_VERSION and XLOG_PAGE_MAGIC. Whack XLOG_PAGE_MAGIC back to
the sequence it used to follow, before hot standby and subsequent patches
changed it to 0x9003.

Normal superuser processes are allowed to connect even when the database
system is shutting down, or when fewer than superuser_reserved_connection
slots remain.  This is intended to make sure an administrator can log in
and troubleshoot, so don't extend these same courtesies to users connecting
for replication.

Also, make the name of the GUC and the name of the backing variable match.
Alnong the way, clean up a couple of slight typographical errors in the
related docs.

The logic for determining whether to materialize has been significantly
overhauled for 9.0.  In case there should be any doubt about whether
materialization is a win in any particular case, this should provide a
convenient way of seeing what happens without it; but even with enable_material
turned off, we still materialize in cases where it is required for
correctness.

Thanks to Tom Lane for the review.