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.

displayed in the postmaster log.  This avoids Windows-specific problems with
localized time zone names that are in the wrong encoding, and generally seems
like a good idea to forestall other potential platform-dependent issues.
To preserve the existing behavior that all backends will log in the same time
zone, create a new GUC variable log_timezone that can only be changed on a
system-wide basis, and reference log-related calculations to that zone instead
of the TimeZone variable.

This fixes the issue reported by Hiroshi Saito that timestamps printed by
xlog.c startup could be improperly localized on Windows.  We still need a
simpler patch for that problem in the back branches, however.

so that we will be able to create a cookie for all processes for CSVlogs.
It is set wherever MyProcPid is set. Take the opportunity to remove the now
unnecessary session-only restriction on the %s and %c escapes in log_line_prefix.

log_min_error_statement is active and there is some problem in logging the
current query string; for example, that it's too long to include in the log
message without running out of memory.  This problem has existed since the
log_min_error_statement feature was introduced.  No doubt the reason it
wasn't detected long ago is that 8.2 is the first release that defaults
log_min_error_statement to less than PANIC level.
Per report from Bill Moran.

lot more sensible if we check the chunk-output case first.  Not
back-patched since it's just a cosmetic improvement.

be catching stderr output, and we are not ourselves the
syslogger. Otherwise, go directly to stderr.
Bug noticed by Tom Lane.
Backpatch as far as 8.0.

reassembled in the syslogger before writing to the log file. This prevents
partial messages from being written, which mucks up log rotation, and
messages from different backends being interleaved, which causes garbled
logs. Backport as far as 8.0, where the syslogger was introduced.

Tom Lane and Andrew Dunstan

which is the only state in which it's safe to initiate database queries.
It turns out that all but two of the callers thought that's what it meant;
and the other two were using it as a proxy for "will GetTopTransactionId()
return a nonzero XID"?  Since it was in fact an unreliable guide to that,
make those two just invoke GetTopTransactionId() always, then deal with a
zero result if they get one.

and for other compilers, insert a dummy exit() call so that they understand
PG_RE_THROW() doesn't return.  Insert fflush(stderr) in ExceptionalCondition,
per recent buildfarm evidence that that might not happen automatically on some
platforms.  And const-ify ExceptionalCondition's declaration while at it.

isn't any place to throw the error to.  If so, we should treat the error
as FATAL, just as we would have if it'd been thrown outside the PG_TRY
block to begin with.

Although this is clearly a *potential* source of bugs, it is not clear
at the moment whether it is an *actual* source of bugs; there may not
presently be any PG_TRY blocks in code that can be reached with no outer
longjmp catcher.  So for the moment I'm going to be conservative and not
back-patch this.  The change breaks ABI for users of PG_RE_THROW and hence
might create compatibility problems for loadable modules, so we should not
put it into released branches without proof that it's needed.

log_min_messages does; and arrange to suppress the duplicative output
that would otherwise result from log_statement and log_duration messages.
Bruce Momjian and Tom Lane.

running as a service on Win32.

Per report from Harald Armin Massa.

function is_log_level_output(), for code clarity.

back-stamped for this.

not destroy them.  Maybe we can adjust pgindent sometime.

because on that platform strftime produces localized zone names in varying
encodings.  Even though it's only in a comment, this can cause encoding
errors when reloading the dump script.  Per suggestion from Andreas
Seltenreich.  Also, suppress %Z on Windows in the %s escape of
log_line_prefix ... not sure why this one is different from the other two,
but it shouldn't be.

promoted to FATAL) end in exit(1) not exit(0).  Then change the postmaster to
allow exit(1) without a system-wide panic, but not for the startup subprocess
or the bgwriter.  There were a couple of places that were using exit(1) to
deliberately force a system-wide panic; adjust these to be exit(2) instead.
This fixes the problem noted back in July that if the startup process exits
with elog(ERROR), the postmaster would think everything is hunky-dory and
proceed to start up.  Alternative solutions such as trying to run the entire
startup process as a critical section seem less clean, primarily because of
the fact that a fair amount of startup code is shared by all postmaster
children in the EXEC_BACKEND case.  We'd need an ugly special case somewhere
near the head of main.c to make it work if it's the child process's
responsibility to determine what happens; and what's the point when the
postmaster already treats different children differently?

severity.  This is to ensure the user can cancel a query that's spitting
out lots of notice/warning messages, even if they're coming from a loop
that doesn't otherwise contain a CHECK_FOR_INTERRUPTS.  Per gripe from
Stephen Frost.

to performance.  (A wholesale effort to get rid of strncpy should be
undertaken sometime, but not during beta.)  This commit also fixes dynahash.c
to correctly truncate overlength string keys for hashtables, so that its
callers don't have to anymore.

Strip unused include files out unused include files, and add needed
includes to C files.

The next step is to remove unused include files in C files.

changing semantics too much.  statement_timestamp is now set immediately
upon receipt of a client command message, and the various places that used
to do their own gettimeofday() calls to mark command startup are referenced
to that instead.  I have also made stats_command_string use that same
value for pg_stat_activity.query_start for both the command itself and
its eventual replacement by <IDLE> or <idle in transaction>.  There was
some debate about that, but no argument that seemed convincing enough to
justify an extra gettimeofday() call.

comment line where output as too long, and update typedefs for /lib
directory.  Also fix case where identifiers were used as variable names
in the backend, but as typedefs in ecpg (favor the backend for
indenting).

Backpatch to 8.1.X.

to assume that the string pointer passed to set_ps_display is good forever.
There's no need to anyway since ps_status.c itself saves the string, and
we already had an API (get_ps_display) to return it.
I believe this explains Jim Nasby's report of intermittent crashes in
elog.c when %i format code is in use in log_line_prefix.
While at it, repair a previously unnoticed problem: on some platforms such as
Darwin, the string returned by get_ps_display was blank-padded to the maximum
length, meaning that lock.c's attempt to append " waiting" to it never worked.

those names.  (Debug and None were pretty bad names anyway.)  I hope I catched
all uses of the names in comments too.

the facility has been set, the facility gets set to LOCAL0 and cannot
be changed later.  This seems reasonably plausible to happen, particularly
at higher debug log levels, though I am not certain it explains Han Holl's
recent report.  Easiest fix is to teach the code how to change the value
on-the-fly, which is nicer anyway.  I made the settings PGC_SIGHUP to
conform with log_destination.

of GUC memory doesn't cause us to start emitting a bogus ident string.
Per report from Han Holl.  Also some trivial code cleanup in write_syslog.

stderr-in-service or output-from-syslogger-in-service code. Previously
everything was flagged as ERRORs there, which caused all instances to
log "LOG: logger shutting down" as error...

Please apply for 8.1. I'd also like it considered for 8.0 since logging
non-errors as errors can be cause for alarm amongst people who actually
look at their logs...

Magnus Hagander

code beautification too.

These contain the SQLSTATE and error message of the current exception,
respectively. They are scope-local variables that are only defined
in exception handlers (so attempting to reference them outside an
exception handler is an error). Update the regression tests and the
documentation.

Also, do some minor related cleanup: export an unpack_sql_state()
function from the backend and use it to unpack a SQLSTATE into a
string, and add a free_var() function to pl_exec.c

Original patch from Pavel Stehule, review by Neil Conway.

millisecond timestamps (%m) and remote host (%h). The milliseconds are
useful for QPS measurements.

Ed L.