for sure ;-)). It now also optimizes more cases, such as %_%_. Improve
comments too. Per bug #5478.
In passing, also rename the TCHAR macro to GETCHAR, because pgindent is
messing with the formatting of the former (apparently it now thinks TCHAR
is a typedef name).
Back-patch to 8.3, where the bug was introduced.
is treated like end-of-input, if nulls sort last in that column and we are not
doing outer-join filling for that input. In such a case, the tuple cannot
join to anything from the other input (because we assume mergejoinable
operators are strict), and neither can any tuple following it in the sort
order. If we're not interested in doing outer-join filling we can just
pretend the tuple and its successors aren't there at all. This can save a
great deal of time in situations where there are many nulls in the join
column, as in a recent example from Scott Marlowe. Also, since the planner
tends to not count nulls in its mergejoin scan selectivity estimates, this
is an important fix to make the runtime behavior more like the estimate.
I regard this as an omission in the patch I wrote years ago to teach mergejoin
that tuples containing nulls aren't joinable, so I'm back-patching it. But
only to 8.3 --- in older versions, we didn't have a solid notion of whether
nulls sort high or low, so attempting to apply this optimization could break
things.
This saves cycles in get_ps_display() on many popular platforms, and more
importantly ensures that get_ps_display() will correctly return an empty
string if init_ps_display() hasn't been called yet. Per trouble report
from Ray Stell, in which log_line_prefix %i produced junk early in backend
startup.
Back-patch to 8.0. 7.4 doesn't have %i and its version of get_ps_display()
makes no pretense of avoiding pad junk anyhow.
before it checks whether the expression is immutable. This covers two cases
that were previously handled poorly:
1. SQL function inlining could reduce the apparent volatility of the
expression, allowing an expression to be accepted where it previously would
not have been. As an example, polymorphic functions must be marked with the
worst-case volatility they have for any argument type, but for specific
argument types they might not be so volatile, so indexing could be allowed.
(Since the planner will refuse to inline functions in cases where the
apparent volatility of the expression would increase, this won't break
any cases that were accepted before.)
2. A nominally immutable function could have default arguments that are
volatile expressions. In such a case insertion of the defaults will increase
both the apparent and actual volatility of the expression, so it is
*necessary* to check this before allowing the expression to be indexed.
Back-patch to 8.4, where default arguments were introduced.
In particular, it's bad to start walreceiver when in state
PM_WAIT_BACKENDS, because we have no provision to kill walreceiver
when in that state.
Fujii Masao
otherwise we effectively rate-limit the streaming as pointed out by
Simon Riggs. Also, send the WAL in smaller chunks, to respond to signals
more promptly.
During Hot Standby we need to check for buffer pin deadlocks when the
Startup process begins to wait, in case it never wakes up again. We
previously made the deadlock check immediately on the basis it was
cheap, though clearer thinking and prima facie evidence shows that
was too simple. Refactor existing code to make it easy to add in
deferral of deadlock check until deadlock_timeout allowing a good
reduction in deadlock checks since far few buffer pins are held for
that duration. It's worth doing anyway, though major goal is to
prevent further reports of context switching with high numbers of
users on occasional tests.
requests for client certs. This lets a client with a keystore select the
appropriate client certificate to send. In particular, this is necessary
to get Java clients to work in all but the most trivial configurations.
Per discussion of bug #5468.
Craig Ringer
1. If we receive a fast shutdown request while in the PM_STARTUP state,
process it just as we would in PM_RECOVERY, PM_HOT_STANDBY, or PM_RUN.
Without this change, an early fast shutdown followed by Hot Standby causes
the database to get stuck in a state where a shutdown is pending (so no new
connections are allowed) but the shutdown request is never processed unless
we end Hot Standby and enter normal running.
2. Avoid removing the backup label file when a smart or fast shutdown occurs
during recovery. It makes sense to do this once we've reached normal running,
since we must be taking a backup which now won't be valid. But during
recovery we must be recovering from a previously taken backup, and any backup
label file is needed to restart recovery from the right place.
Fujii Masao and Robert Haas
If the original IN operator is cross-type, for example int8 = int4,
we need to use int4 < int4 to sort the inner data and int4 = int4
to unique-ify it. We got the first part of that right, but tried to
use the original IN operator for the equality checks. Per bug #5472
from Vlad Romascanu.
Backpatch to 8.4, where the bug was introduced by the patch that unified
SortClause and GroupClause. I was able to take out a whole lot of on-the-fly
calls of get_equality_op_for_ordering_op(), but failed to realize that
I needed to put one back in right here :-(
so simply leads to data waiting in wal_buffers which then causes
later commits to potentially do emergency writes and for all forms
of replication to be potentially delayed without need or benefit.
Issue pointed out exactly by Fujii Masao, following bug report
by Robert Haas on a separate though related topic.
of requirements and documentation on LogStandbySnapshot(). Fixes
two minor bugs reported by Tom Lane that would lead to an incorrect
snapshot after transaction wraparound. Also fix two other problems
discovered that would give incorrect snapshots in certain cases.
ProcArrayApplyRecoveryInfo() substantially rewritten. Some minor
refactoring of xact_redo_apply() and ExpireTreeKnownAssignedTransactionIds().
archive_command) as soon as possible, namely just before issuing a new call
of archive_command, even when there is a backlog of files to be archived.
The original coding would only absorb new settings after clearing the backlog
and returning to the outer loop. Per discussion.
Back-patch to 8.3. The logic in prior versions is a bit different and it
doesn't seem worth taking any risks of breaking it.
Now validators work properly even when the settings contain
parameters that affect behavior of the function, like search_path.
Reported by Erwin Brandstetter.
MIN or MAX, we must take care to insert the added qual in a legal place among
the existing indexquals, if any. The btree index AM requires the quals to
appear in index-column order. We didn't have to worry about this before
because "target IS NOT NULL" was just treated as a plain scan filter condition;
but as of 9.0 it can be an index qual and then it has to follow the rule.
Per report from Ian Barwick.
My initial impression that glibc was measuring the precision in characters
(which is what the Linux man page says it does) was incorrect. It does take
the precision to be in bytes, but it also tries to truncate the string at a
character boundary. The bottom line remains the same: it will mess up
if the string is not in the encoding it expects, so we need to avoid %.*s
anytime there's a significant risk of that. Previous code changes are still
good, but adjust the comments to reflect this knowledge. Per research by
Hernan Gonzalez.
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".
minRecoveryPoint in control file when replaying a parameter change record,
to ensure that we don't allow hot standby on WAL generated without
wal_level='hot_standby' after a standby restart.
field of the WAL record. The previous coding always wrote to the main fork,
resulting in data corruption if the page was meant to go into a non-default
fork.
At present, the only operation that can produce such WAL records is
ALTER TABLE/INDEX SET TABLESPACE when executed with archive_mode = on.
Data corruption would be observed on standby slaves, and could occur on the
master as well if a database crash and recovery occurred after committing
the ALTER and before the next checkpoint. Per report from Gordon Shannon.
Back-patch to 8.4; the problem doesn't exist in earlier branches because
we didn't have a concept of multiple relation forks then.
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.
returns EINVAL for an existing shared memory segment. Although it's not
terribly sensible, that behavior does meet the POSIX spec because EINVAL
is the appropriate error code when the existing segment is smaller than the
requested size, and the spec explicitly disclaims any particular ordering of
error checks. Moreover, it does in fact happen on OS X and probably other
BSD-derived kernels. (We were able to talk NetBSD into changing their code,
but purging that behavior from the wild completely seems unlikely to happen.)
We need to distinguish collision with a pre-existing segment from invalid size
request in order to behave sensibly, so it's worth some extra code here to get
it right. Per report from Gavin Kistner and subsequent investigation.
Back-patch to all supported versions, since any of them could get used
with a kernel having the debatable behavior.
to perform a backup without archive_mode being enabled. This gives up some
user-error protection in order to improve usefulness for streaming-replication
scenarios. Per discussion.
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.
contrib/intarray is loaded. Per bug #5417 from Kenaniah Cerny.
Not forcing initdb since backend doesn't directly depend on this,
and few people have run into it.
rather than returning NULL for some-but-not-all failures as they used to.
Remove now-redundant tests for NULL from call sites.
We had to do something about this because many call sites were failing to
check for NULL; and changing it like this seems a lot more useful and
mistake-proof than adding checks to the call sites without them.
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.
to RFC 3986. In particular, these characters now terminate the path part
of a URL: '"', '<', '>', '\', '^', '`', '{', '|', '}'. The previous behavior
was inconsistent and depended on whether a "?" was present in the path.
Per gripe from Donald Fraser and spec research by Kevin Grittner.
This is a pre-existing bug, but not back-patching since the risks of
breaking existing applications seem to outweigh the benefits.
and be more tense about the locking requirements for it, to improve performance
in Hot Standby mode. In passing fix a few bugs and improve a number of
comments in the existing HS code.
Simon Riggs, with some editorialization by Tom
