This patch fixes three places (which AFAICT is all of them) where runtime
was O(N^2) in the number of TOC entries, by using an index array to replace
linear searches of the TOC list. This performance issue is a bit less bad
than those recently fixed, because it depends on the number of items dumped
not the number in the source database, so the problem can be dodged by
doing partial dumps.
The previous coding already had an instance of one of the two index arrays
needed, but it was only calculated in parallel-restore cases; now we need
it all the time. I also chose to move the arrays into the ArchiveHandle
data structure, to make this code a bit more ready for the day that we
try to sling multiple ArchiveHandles around in pg_dump or pg_restore.
Since we still need some server-side work before pg_dump can really cope
nicely with tens of thousands of tables, there's probably little point in
back-patching.
Drop special handling of host component with slashes to mean
Unix-domain socket. Specify it as separate parameter or using
percent-encoding now.
Allow omitting username, password, and port even if the corresponding
designators are present in URI.
Handle percent-encoding in query parameter keywords.
Alex Shulgin
some documentation improvements by myself
Set E081 Basic Privileges to supported, since by the letter of it, we
support it, even though not all possible forms of USAGE privileges are
implemented.
The only interesting-for-performance case wherein we force heapscan here
is when we're rebuilding the relcache init file, and the only such case
that is likely to be examining a catalog big enough to be syncscanned is
RelationBuildTupleDesc. But the early-exit optimization in that code gets
broken if we start the scan at a random place within the catalog, so that
allowing syncscan is actually a big deoptimization if pg_attribute is large
(at least for the normal case where the rows for core system catalogs have
never been changed since initdb). Hence, prevent syncscan here. Per my
testing pursuant to complaints from Jeff Frost and Greg Sabino Mullane,
though neither of them seem to have actually hit this specific problem.
Back-patch to 8.3, where syncscan was introduced.
Previously, casts to name could generate invalidly-encoded results.
Also, make these functions match namein() more exactly, by consistently
using palloc0() instead of ad-hoc zeroing code.
Back-patch to all supported branches.
Karl Schnaitter and Tom Lane
The previous coding presented a significant bottleneck when dumping
databases containing many thousands of schemas, since the total time
spent searching would increase roughly as O(N^2) in the number of objects.
Noted by Jeff Janes, though I rewrote his proposed patch to use the
existing findObjectByOid infrastructure.
Since this is a longstanding performance bug, backpatch to all supported
versions.
When backing up from a standby server, the backup process
will not automatically switch xlog segment. So we must
accept a partially transferred xlog file in this case, but
rename it into position anyway.
In passing, merge the two callbacks for segment end and
stop stream into a single callback, since their implementations
were close to identical, and rename this callback to
reflect that it stops streaming rather than continues it.
Patch by Magnus Hagander, review by Fujii Masao
zaptreesubs() was coded to unconditionally reset a capture subre's
corresponding pmatch[] entry. However, in regexes without backrefs, that
array is caller-supplied and might not have as many entries as the regex
has capturing parens. So check the array length and do nothing if there
is no corresponding entry, much as subset() does. Failure to check this
resulted in a stack clobber in the case reported by Marko Kreen.
This bug appears to have been latent in the regex library from the
beginning. It was not exposed because find() called dissect() not
cdissect(), and the dissect() code path didn't ever call zaptreesubs()
(formerly zapmem()). When I unified dissect() and cdissect() in commit
4dd78bf37a, the problem was exposed.
Now that I've seen this, I'm rather suspicious that we might need to
back-patch it; but will refrain for now, for lack of evidence that
the case can be hit in the previous coding.
If a seqscan encounters many consecutive pages containing only dead tuples,
it can remain in the loop in heapgettup for a long time, and there was no
CHECK_FOR_INTERRUPTS anywhere in that loop. This meant there were
real-world situations where a query would be effectively uncancelable for
long stretches. Add a check placed to occur once per page, which should be
enough to provide reasonable response time without adding any measurable
overhead.
Report and patch by Merlin Moncure (though I tweaked it a bit).
Back-patch to all supported branches.
When the column name is an unqualified name, rather than table.column,
the error message complains about too many dotted names, which is
wrong. Report by Peter Eisentraut based on examination of the
sepgsql regression test output, but the problem also affects COMMENT.
New wording as suggested by Tom Lane.
In commit d526575f89, we changed things so
that buffer usage counts are incremented when the buffer is pinned, rather
than when it is unpinned, but the README file didn't get the memo.
Report by Amit Kapila.
There is no reason to do this as early as possible in postmaster startup,
and good reason not to do it until we have completely created the
postmaster's lock file, namely that it might contribute to pg_ctl thinking
that postmaster startup has timed out. (This would require a rather
unusual amount of time to be spent scanning temp file directories, but we
have at least one field report of it happening reproducibly.)
Back-patch to 9.1. Before that, pg_ctl didn't wait for additional info to
be added to the lock file, so it wasn't a problem.
Note that this is not a complete fix to the slow-start issue in 9.1,
because we still had identify_system_timezone being run during postmaster
start in 9.1. But that's at least a reasonably well-defined delay, with
an easy workaround if needed, whereas the temp-files scan is not so
predictable and cannot be avoided.
The accurate info about what's in a lock file has been in miscadmin.h
for some time, so let's just make this comment point there instead of
maintaining a duplicative copy.
For the record, fe-print.c is also missing, but it's sort of
deprecated, and the string internationalization there has some issues,
and it doesn't seem worth fixing that. So let's leave that out.
When we create a temporary copy of the old node buffer, in stack, we mustn't
leak that into any of the long-lived data structures. Before this patch,
when we called gistPopItupFromNodeBuffer(), it got added to the array of
"loaded buffers". After gistRelocateBuildBuffersOnSplit() exits, the
pointer added to the loaded buffers array points to garbage. Often that goes
unnotied, because when we go through the array of loaded buffers to unload
them, buffers with a NULL pageBuffer are ignored, which can often happen by
accident even if the pointer points to garbage.
This patch fixes that by marking the temporary copy in stack explicitly as
temporary, and refrain from adding buffers marked as temporary to the array
of loaded buffers.
While we're at it, initialize nodeBuffer->pageBlocknum to InvalidBlockNumber
and improve comments a bit. This isn't strictly necessary, but makes
debugging easier.
Per recent discussion, the error message for this was actually a trifle
inaccurate, since it said "cannot be cast" which might be incorrect.
Adjust that wording, and add a HINT suggesting that a USING clause might
be needed.
If the amount of freespace on page was less than the amount reserved by
fillfactor, the calculation would underflow.
This fixes bug #6643 reported by Tomonari Katsumata.
We have no need for a timeout here really, but some broken products from
Redmond seem to lose FD_READ events occasionally, and waking up and
retrying the recv() is the only known way to work around that. Perhaps
somebody will be motivated to figure out a better answer here; but not I.
The BSD-ish members of the buildfarm all seem to think removing this
was a bad idea. It looks to me like it resulted in omitting the system
header inclusion necessary to detect the fields of struct tm correctly.
Since we have chosen to report socket EOF and error conditions via the
WL_SOCKET_READABLE flag bit, it's unsafe to wait only for
WL_SOCKET_WRITEABLE; the caller would never be notified of the socket
condition, and in some of these implementations WaitLatchOrSocket would
busy-wait until something else happens. Add this restriction to the API
specification, and add Asserts to check that callers don't try to do that.
At some point we might want to consider adjusting the API to relax this
restriction, but until we have an actual use case for waiting on a
write-only socket, it seems premature to design a solution.
ENABLE_DTRACE unused as of a7b7b07af3
HAVE_ERR_SET_MARK unused as of 4ed4b6c54e
HAVE_FCVT unused as of 4553e1d80f
HAVE_STRUCT_SOCKADDR_UN unused as of b4cea00a1f
HAVE_SYSCONF unused as of f83356c7f5
TM_IN_SYS_TIME never used, obsolescent per Autoconf documentation
Test results from buildfarm members mastodon/narwhal (Windows Server 2003)
make it look like that platform just plain loses FD_READ events
occasionally, and the only reason our previous coding seemed to work was
that it timed out every couple of seconds and retried the whole operation.
Try to verify this by reinserting a finite timeout into the pgstat loop.
This isn't meant to be a permanent patch either, just to confirm or
disprove a theory.
This should get rid of the usage of pgwin32_waitforsinglesocket entirely,
and perhaps thereby remove the race condition that's evidently still
present on some versions of Windows. The previous arrangement was a bit
unsafe anyway, since waiting at the recv() would not allow pgstat to notice
postmaster death.
When the "hot" members of PGPROC were split off to separate PGXACT structs,
many PGPROC fields referred to in comments were moved to PGXACT, but the
comments were neglected in the commit. Mostly this is just a search/replace
of PGPROC with PGXACT, but the way the dummy PGPROC entries are created for
prepared transactions changed more, making some of the comments totally
bogus.
Noah Misch
Log main-loop blocking events and the results of inquiry messages.
This is to get some clarity as to what's happening on those Windows
buildfarm members that still don't like the latch-ified stats collector.
This bulks up the postmaster log a tad, so I won't leave it in place for
long.
If the tablespace directory is missing entirely, we allow DROP TABLESPACE
to go through, on the grounds that it should be possible to clean up the
catalog entry in such a situation. However, we forgot that the pg_tblspc
symlink might still be there. We should try to remove the symlink too
(but not fail if it's no longer there), since not doing so can lead to
weird behavior subsequently, as per report from Michael Nolan.
There was some discussion of adding dependency links to prevent DROP
TABLESPACE when the catalogs still contain references to the tablespace.
That might be worth doing too, but it's an orthogonal question, and in
any case wouldn't be back-patchable.
Back-patch to 9.0, which is as far back as the logic looks like this.
We could possibly do something similar in 8.x, but given the lack of
reports I'm not sure it's worth the trouble, and anyway the case could
not arise in the form the logic is meant to cover (namely, a post-DROP
transaction rollback having resurrected the pg_tablespace entry after
some or all of the filesystem infrastructure is gone).
This reverts commit cb2f2873d6, restoring
the latch-ified stats collector logic. We'll soon see if this works any
better on the Windows buildfarm machines.
Make sure WaitLatchOrSocket regards FD_CLOSE as a read-ready condition.
We might want to tweak this further, but it was surely wrong as-is.
Make pgwin32_waitforsinglesocket detach its private event object from the
passed socket before returning. I suspect that failure to do so leads
to race conditions when other code (such as WaitLatchOrSocket) attaches
a different event object to the same socket. Moreover, the existing
coding meant that repeated calls to pgwin32_waitforsinglesocket would
perform ResetEvent on an event actively connected to a socket, which
is rumored to be an unsafe practice; the WSAEventSelect documentation
appears to recommend against this, though it does not say not to do it
in so many words.
Also, uniformly use the coding pattern "WSAEventSelect(s, NULL, 0)" to
detach events from sockets, rather than passing the event in the second
parameter. The WSAEventSelect documentation says that the second parameter
is ignored if the third is 0, so theoretically this should make no
difference. However, elsewhere on the same reference page the use of NULL
in this context is recommended, and I have found suggestions on the net
that some versions of Windows have bugs with a non-NULL second parameter
in this usage.
Some other mostly-cosmetic cleanup, such as using the right one of
WSAGetLastError and GetLastError for reporting errors from these functions.
rc should be an int here, not a pgsocket. Fairly harmless as long as
pgsocket is an integer type, but nonetheless wrong. Error introduced
in commit 87091cb1f1.
syslogger was coded to wake up once per second whether there was anything
useful to do or not. As part of our campaign to reduce the server's idle
power consumption, change it to use a latch for waiting. Now, in the
absence of any data to log or any signals to service, it will only wake up
at the programmed logfile rotation times (if any).
When using poll(), EOF on a socket is reported with the POLLHUP not
POLLIN flag (at least on Linux). WaitLatchOrSocket failed to check
this bit, causing it to go into a busy-wait loop if EOF occurs.
We earlier fixed the same mistake in the test for the state of the
postmaster_alive socket, but missed it for the caller-supplied socket.
Fortunately, this error is new in 9.2, since 9.1 only had a select()
based code path not a poll() based one.
