Stephen Frost, somewhat rewritten by me

This reverts commit a8a88679, committed
by me earlier today (2011-01-12).  This isn't safe inside an aborted
transaction.

Noted by Tom Lane.

Stephen Frost, with some editorialization by me.

The nominally equivalent call appendStringInfo(buf, "%s", str) can be
significantly slower when str is large.  In particular, the former usage in
EVALUATE_MESSAGE led to O(N^2) behavior when collecting a large number of
context lines, as I found out while testing recursive functions.  The other
changes are just neatnik-ism and seem unlikely to save anything meaningful,
but a cycle shaved is a cycle earned.

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.

path when CSV logging is configured but not yet operational.  It's sufficient
to send the message to stderr, as we were already doing, and the "Not safe"
gripe has already confused at least two core members ...

Backpatch to 9.0, but not further --- doesn't seem appropriate to change
this behavior in stable branches.

Depending on which spec you read, field widths and precisions in %s may be
counted either in bytes or characters.  Our code was assuming bytes, which
is wrong at least for glibc's implementation, and in any case libc might
have a different idea of the prevailing encoding than we do.  Hence, for
portable results we must avoid using anything more complex than just "%s"
unless the string to be printed is known to be all-ASCII.

This patch fixes the cases I could find, including the psql formatting
failure reported by Hernan Gonzalez.  In HEAD only, I also added comments
to some places where it appears safe to continue using "%.*s".

(hope I got 'em all).  Per discussion, this release will be 9.0 not 8.5.

Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record.

New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far.

This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required.

Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit.

Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.

pg_stat_activity and recorded in log entries.

Dave Page, reviewed by Andres Freund

as necessary.

Itagaki Takahiro with some changes from me

Author: Guillaume Smet <guillaume.smet@gmail.com>

to restore gcc's ability to crosscheck format arguments within elog.c.
Noted in a test compilation with -Wformat-nonliteral enabled.

provided by Andrew.

by extending the ereport() API to cater for pluralization directly.  This
is better than the original method of calling ngettext outside the elog.c
code because (1) it avoids double translation, which wastes cycles and in
the worst case could give a wrong result; and (2) it avoids having to use
a different coding method in PL code than in the core backend.  The
client-side uses of ngettext are not touched since neither of these concerns
is very pressing in the client environment.  Per my proposal of yesterday.

encoding conversion of any elog/ereport message being sent to the frontend.
This generalizes a patch that I put in last October, which suppressed
translation of only specific messages known to be associated with recursive
can't-translate-the-message behavior.  As shown in bug #4680, we need a more
general answer in order to have some hope of coping with broken encoding
conversion setups.  This approach seems a good deal less klugy anyway.

Patch in all supported branches.

Hiroshi Inoue

consistent. Currently, in csvlog, vxid of an auxiliary process isn't
displayed. On the other hand, in stderr/syslog, invalid vxid (-1/0) of
that is displayed.

Fujii Masao

recursion when we are unable to convert a localized error message to the
client's encoding.  We've been over this ground before, but as reported by
Ibrar Ahmed, it still didn't work in the case of conversion failures for
the conversion-failure message itself :-(.  Fix by installing a "circuit
breaker" that disables attempts to localize this message once we get into
recursion trouble.

Patch all supported branches, because it is in fact broken in all of them;
though I had to add some missing translations to the older branches in
order to expose the failure in the particular test case I was using.

formatted_start_time.

the ereport macro.  Included in this commit are enough files for starting
plpgsql, plpython, plperl and pltcl translations.

There are still some weak spots around JOIN USING and relation alias lists,
but most errors reported within backend/parser/ now have locations.

1024 to improve performance when sending large elog messages.  Also add a
comment about why we use that number.

Since this represents an externally visible behavior change, and might
possibly result in portability issues, it seems best not to back-patch it.

log message at newlines cost O(N^2) for very long messages with few or no
newlines.  For messages in the megabyte range this became the dominant cost.
Per gripe from Achilleas Mantzios.

Patch all the way back, since this is a safe change with no portability
risks.  I am also thinking of increasing PG_SYSLOG_LIMIT, but that should
be done separately.

errdetail except the string goes only to the server log, replacing the normal
errdetail there.  This provides a reasonably clean way of dealing with error
details that are too security-sensitive or too bulky to send to the client.

This commit just adds the infrastructure --- actual uses to follow.

variables to it. More need to be converted, but I wanted to get this in
before it conflicts with too much...

Other than just centralising the text-to-int conversion for parameters,
this allows the pg_settings view to contain a list of available options
and allows an error hint to show what values are allowed.

with the logged event.  CSV logs are now a first-class citizen along plain
text logs in that they carry much of the same information.

Per complaint from depesz on bug #3799.

the same transaction can be identified even when no regular XID was assigned.
This seems essential after addition of the lazy-XID patch.  Also some
minor code cleanup in write_csvlog().

rows will normally never obtain an XID at all.  We already did things this way
for subtransactions, but this patch extends the concept to top-level
transactions.  In applications where there are lots of short read-only
transactions, this should improve performance noticeably; not so much from
removal of the actual XID-assignments, as from reduction of overhead that's
driven by the rate of XID consumption.  We add a concept of a "virtual
transaction ID" so that active transactions can be uniquely identified even
if they don't have a regular XID.  This is a much lighter-weight concept:
uniqueness of VXIDs is only guaranteed over the short term, and no on-disk
record is made about them.

Florian Pflug, with some editorialization by Tom.

the same amount of memory in ErrorContext as standard logs.

redirect_stderr to logging_collector.
Original patch from Arul Shaji, subsequently modified by Greg Smith, and then
heavily modified by me.

between the setting of log_line_prefix and the setting of log_timezone.  We
can't realistically set log_timezone any earlier than we do now, so the best
behavior seems to be to use GMT zone if any timestamps are to be logged during
early startup.  Create a dummy zone variable with a minimal definition of GMT
(in particular it will never know about leap seconds), so that we can set it
up without reference to any external files.