Tom Lane [Sun, 3 Mar 2013 22:40:04 +0000 (17:40 -0500)]
Fix SQL function execution to be safe with long-lived FmgrInfos.
fmgr_sql had been designed on the assumption that the FmgrInfo it's called
with has only query lifespan. This is demonstrably unsafe in connection
with range types, as shown in bug #7881 from Andrew Gierth. Fix things
so that we re-generate the function's cache data if the (sub)transaction
it was made in is no longer active.
Back-patch to 9.2. This might be needed further back, but it's not clear
whether the case can realistically arise without range types, so for now
I'll desist from back-patching further.
Tom Lane [Sat, 2 Mar 2013 02:33:38 +0000 (21:33 -0500)]
Eliminate memory leaks in plperl's spi_prepare() function.
Careless use of TopMemoryContext for I/O function data meant that repeated
use of spi_prepare and spi_freeplan would leak memory at the session level,
as per report from Christian Schröder. In addition, spi_prepare
leaked a lot of transient data within the current plperl function's SPI
Proc context, which would be a problem for repeated use of spi_prepare
within a single plperl function call; and it wasn't terribly careful
about releasing permanent allocations in event of an error, either.
In passing, clean up some copy-and-pasteos in query-lookup error messages.
Tom Lane [Wed, 27 Feb 2013 15:40:10 +0000 (10:40 -0500)]
Add missing error check in regexp parser.
parseqatom() failed to check for an error return (NULL result) from its
recursive call to parsebranch(), and in consequence could crash with a
null-pointer dereference after an error return. This bug has been there
since day one, but wasn't noticed before, probably because most error cases
in parsebranch() didn't actually lead to returning NULL. Add the missing
error check, and also tweak parsebranch() to exit in a less indirect
fashion after a call to parseqatom() fails.
We must still initialize minRecoveryPoint if we start straight with archive
recovery, e.g when recovering from a normal base backup taken with
pg_start/stop_backup. Otherwise we never consider the system consistent.
If recovery.conf is created after "pg_ctl stop -m i", do crash recovery.
If you create a base backup using an atomic filesystem snapshot, and try to
perform PITR starting from that base backup, or if you just kill a master
server and create recovery.conf to put it into standby mode, we don't know
how far we need to recover before reaching consistency. Normally in crash
recovery, we replay all the WAL present in pg_xlog, and assume that we're
consistent after that. And normally in archive recovery, minRecoveryPoint,
backupEndRequired, or backupEndPoint is set in the control file, indicating
how far we need to replay to reach consistency. But if the server was
previously up and running normally, and you kill -9 it or take an atomic
filesystem snapshot, none of those fields are set in the control file.
The solution is to perform crash recovery first, replaying all the WAL in
pg_xlog. After that's done, we assume that the system is consistent like in
normal crash recovery, and switch to archive recovery mode after that.
Per report from Kyotaro HORIGUCHI. In his scenario, recovery.conf was
created after "pg_ctl stop -m i". I'm not sure we need to support that exact
scenario, but we should support backing up using a filesystem snapshot,
which looks identical.
This issue goes back to at least 9.0, where hot standby was introduced and
we started to track when consistency is reached. In 9.1 and 9.2, we would
open up for hot standby too early, and queries could briefly see an
inconsistent state. But 9.2 made it more visible, as we started to PANIC if
we see a reference to a non-existing page during recovery, if we've already
reached consistency. This is a fairly big patch, so back-patch to 9.2 only,
where the issue is more visible. We can consider back-patching further after
this has received some more testing in 9.2 and master.
If a database name contained a '=' character, pg_dumpall failed. The problem
was in the way pg_dumpall passes the database name to pg_dump on the
command line. If it contained a '=' character, pg_dump would interpret it
as a libpq connection string instead of a plain database name.
To fix, pass the database name to pg_dump as a connection string,
"dbname=foo", with the database name escaped if necessary.
Better fix for "unarchived WAL files get deleted on crash recovery" bug.
Revert my earlier fix for the bug that unarchived WAL files get deleted on
crash recovery, commit c9cc7e05c6d82a9781883a016c70d95aa4923122. We create
a .done file for files streamed or restored from archive, so the WAL file
recycling logic used during normal operation works just as well during
archive recovery.
Tom Lane [Wed, 13 Feb 2013 19:07:13 +0000 (14:07 -0500)]
Fix contrib/pg_trgm's similarity() function for trigram-free strings.
Cases such as similarity('', '') produced a NaN result due to computing
0/0. Per discussion, make it return zero instead.
This appears to be the basic cause of bug #7867 from Michele Baravalle,
although it remains unclear why her installation doesn't think Cyrillic
letters are letters.
Since a backend adds itself to the global listener array during
Exec_ListenPreCommit, it's inappropriate for it to remove itself during
Exec_UnlistenCommit or Exec_UnlistenAllCommit --- that leads to failure
when committing a transaction that did UNLISTEN then LISTEN, since we end
up not registered though we should be. (This leads to missing later
notifications, or to Assert failures in assert-enabled builds.) Instead
deal with deregistering at the bottom of AtCommit_Notify, when we know the
final state of the listenChannels list.
Also, simplify the representation of registration status by replacing the
transient backendHasExecutedInitialListen flag with an amRegisteredListener
flag.
Per report from Greg Sabino Mullane. Back-patch to 9.0, where the problem
was introduced during the LISTEN/NOTIFY rewrite.
Tom Lane [Sun, 10 Feb 2013 21:21:32 +0000 (16:21 -0500)]
Further cleanup of gistsplit.c.
After further reflection I was unconvinced that the existing coding is
guaranteed to return valid union datums in every code path for multi-column
indexes. Fix that by forcing a gistunionsubkey() call at the end of the
recursion. Having done that, we can remove some clearly-redundant calls
elsewhere. This should be a little faster for multi-column indexes (since
the previous coding would uselessly do such a call for each column while
unwinding the recursion), as well as much harder to break.
Also, simplify the handling of cases where one side or the other of a
primary split contains only don't-care tuples. The previous coding used a
very ugly hack in removeDontCares() that essentially forced one random
tuple to be treated as non-don't-care, providing a random initial choice of
seed datum for the secondary split. It seems unlikely that that method
will give better-than-random splits. Instead, treat such a split as
degenerate and just let the next column determine the split, the same way
that we handle fully degenerate cases where the two sides produce identical
union datums.
This LOG message was put in over five years ago with the evident
expectation that we'd make all GiST opclasses support secondary split
directly. However, no such thing ever happened, and indeed the number of
opclasses supporting it decreased to zero in 9.2. The reason is that
improving on the default implementation isn't that easy --- the
opclass-specific code that did exist, before 9.2, doesn't appear to have
been any improvement over the default.
Hence, remove the message altogether. There's certainly no point in
nagging users about this in released branches, but I doubt that we'll
ever implement complete opclass-specific support anyway.
Tom Lane [Sun, 10 Feb 2013 17:40:16 +0000 (12:40 -0500)]
Remove vestigial secondary-split support in gist_box_picksplit().
Not only is this implementation of secondary-split not better than the
default implementation in gistsplit.c, it's actually worse. The gistsplit.c
code at least looks to see if switching the left and right sides would make
a better merge with the previously-split tuples, while this doesn't.
In any case it's rather useless to support secondary split only in an edge
case. There used to be more complete support for it here (in chooseLR()),
but that was removed in commit 7f3bd86843e5aad84585a57d3f6b80db3c609916.
It appears to me though that the chooseLR() code was really isomorphic to
the default implementation, since it was still based on choosing the cheaper
way of adding two sub-split vectors that had been chosen without regard to
the primary split initially. I think an implementation of secondary split
that could beat the default implementation would have to be pretty fully
integrated into the split algorithm, not plastered on at the end.
Back-patch to 9.2, but not further; previous branches have the chooseLR()
code which I don't feel a great need to mess with. This is mainly so we
just have two behaviors and not three among the various branches (IOW, this
patch is cleanup for commit 7f3bd86843e5aad84585a57d3f6b80db3c609916's
incomplete removal of secondary-split support).
Tom Lane [Sun, 10 Feb 2013 16:58:23 +0000 (11:58 -0500)]
Document and clean up gistsplit.c.
Improve comments, rename some variables and functions, slightly simplify
a couple of APIs, in an attempt to make this code readable by people other
than its original author.
Even though this is essentially just cosmetic, back-patch to all active
branches, because otherwise it's going to make back-patching future fixes
in this file very painful.
Tom Lane [Fri, 8 Feb 2013 23:03:23 +0000 (18:03 -0500)]
Fix gist_box_same and gist_point_consistent to handle fuzziness correctly.
While there's considerable doubt that we want fuzzy behavior in the
geometric operators at all (let alone as currently implemented), nobody is
stepping forward to redesign that stuff. In the meantime it behooves us
to make sure that index searches agree with the behavior of the underlying
operators. This patch fixes two problems in this area.
First, gist_box_same was using fuzzy equality, but it really needs to use
exact equality to prevent not-quite-identical upper index keys from being
treated as identical, which for example would prevent an existing upper
key from being extended by an amount less than epsilon. This would result
in inconsistent indexes. (The next release notes will need to recommend
that users reindex GiST indexes on boxes, polygons, circles, and points,
since all four opclasses use gist_box_same.)
Second, gist_point_consistent used exact comparisons for upper-page
comparisons in ~= searches, when it needs to use fuzzy comparisons to
ensure it finds all matches; and it used fuzzy comparisons for point <@ box
searches, when it needs to use exact comparisons because that's what the
<@ operator (rather inconsistently) does.
The added regression test cases illustrate all three misbehaviors.
Back-patch to all active branches. (8.4 did not have GiST point_ops,
but it still seems prudent to apply the gist_box_same patch to it.)
Tom Lane [Fri, 8 Feb 2013 03:53:06 +0000 (22:53 -0500)]
Fix performance issue in EXPLAIN (ANALYZE, TIMING OFF).
Commit af7914c6627bcf0b0ca614e9ce95d3f8056602bf, which added the TIMING
option to EXPLAIN, had an oversight: if the TIMING option is disabled
then control in InstrStartNode() goes through an elog(DEBUG2) call, which
typically does nothing but takes a noticeable amount of time to do it.
Tweak the logic to avoid that.
In HEAD, also change the elog(DEBUG2)'s in instrument.c to elog(ERROR).
It's not very clear why they weren't like that to begin with, but this
episode shows that not complaining more vociferously about misuse is
likely to do little except allow bugs to remain hidden.
While at it, adjust some code that was making possibly-dangerous
assumptions about flag bits being in the rightmost byte of the
instrument_options word.
Problem reported by Pavel Stehule (via Tomas Vondra).
Tom Lane [Fri, 8 Feb 2013 00:14:08 +0000 (19:14 -0500)]
Make contrib/btree_gist's GiST penalty function a bit saner.
The previous coding supposed that the first differing bytes in two varlena
datums must have the same sign difference as their overall comparison
result. This is obviously bogus for text strings in non-C locales, and
probably wrong for numeric, and even for bytea I think it was wrong on
machines where char is signed. When the assumption failed, the function
could deliver a zero or negative penalty in situations where such a result
is quite ridiculous, leading the core GiST code to make very bad page-split
decisions.
To fix, take the absolute values of the byte-level differences. Also,
switch the code to using unsigned char not just char, so that the behavior
will be consistent whether char is signed or not.
Per investigation of a trouble report from Tomas Vondra. Back-patch to all
supported branches.
Tom Lane [Thu, 7 Feb 2013 23:22:27 +0000 (18:22 -0500)]
Fix erroneous range-union logic for varlena types in contrib/btree_gist.
gbt_var_bin_union() failed to do the right thing when the existing range
needed to be widened at both ends rather than just one end. This could
result in an invalid index in which keys that are present would not be
found by searches, because the searches would not think they need to
descend to the relevant leaf pages. This error affected all the varlena
datatypes supported by btree_gist (text, bytea, bit, numeric).
Per investigation of a trouble report from Tomas Vondra. (There is also
an issue in gbt_var_penalty(), but that should only result in inefficiency
not wrong answers. I'm committing this separately so that we have a git
state in which it can be tested that bad penalty results don't produce
invalid indexes.) Back-patch to all supported branches.
Tom Lane [Thu, 7 Feb 2013 22:44:10 +0000 (17:44 -0500)]
Repair bugs in GiST page splitting code for multi-column indexes.
When considering a non-last column in a multi-column GiST index,
gistsplit.c tries to improve on the split chosen by the opclass-specific
pickSplit function by considering penalties for the next column. However,
there were two bugs in this code: it failed to recompute the union keys for
the leftmost index columns, even though these might well change after
reassigning tuples; and it included the old union keys in the recomputation
for the columns it did recompute, so that those keys couldn't get smaller
even if they should. The first problem could result in an invalid index
in which searches wouldn't find index entries that are in fact present;
the second would make the index less efficient to search.
Both of these errors were caused by misuse of gistMakeUnionItVec, whose
API was designed in a way that just begged such errors to be made. There
is no situation in which it's safe or useful to compute the union keys for
a subset of the index columns, and there is no caller that wants any
previous union keys to be included in the computation; so the undocumented
choice to treat the union keys as in/out rather than pure output parameters
is a waste of code as well as being dangerous.
Hence, rather than just making a minimal patch, I've changed the API of
gistMakeUnionItVec to remove the "startkey" parameter (it now always
processes all index columns) and treat the attr/isnull arrays as purely
output parameters.
In passing, also get rid of a couple of unnecessary and dangerous uses
of static variables in gistutil.c. It's remarkable that the one in
gistMakeUnionKey hasn't given us portability troubles before now, because
in addition to posing a re-entrancy hazard, it was unsafely assuming that
a static char[] array would have at least Datum alignment.
Per investigation of a trouble report from Tomas Vondra. (There are also
some bugs in contrib/btree_gist to be fixed, but that seems like material
for a separate patch.) Back-patch to all supported branches.
Tom Lane [Thu, 7 Feb 2013 19:44:10 +0000 (14:44 -0500)]
Fix possible failure to send final transaction counts to stats collector.
Normally, we suppress sending a tabstats message to the collector unless
there were some actual table stats to send. However, during backend exit
we should force out the message if there are any transaction commit/abort
counts to send, else the session's last few commit/abort counts will never
get reported at all. We had logic for this, but the short-circuit test
at the top of pgstat_report_stat() ignored the "force" flag, with the
consequence that session-ending transactions that touched no database-local
tables would not get counted. Seems to be an oversight in my commit 641912b4d17fd214a5e5bae4e7bb9ddbc28b144b, which added the "force" flag.
That was back in 8.3, so back-patch to all supported versions.
Tom Lane [Mon, 4 Feb 2013 21:25:10 +0000 (16:25 -0500)]
Prevent execution of enum_recv() from SQL.
This function was misdeclared to take cstring when it should take internal.
This at least allows crashing the server, and in principle an attacker
might be able to use the function to examine the contents of server memory.
The correct fix is to adjust the system catalog contents (and fix the
regression tests that should have caught this but failed to). However,
asking users to correct the catalog contents in existing installations
is a pain, so as a band-aid fix for the back branches, install a check
in enum_recv() to make it throw error if called with a cstring argument.
We will later revert this in HEAD in favor of correcting the catalogs.
Our thanks to Sumit Soni (via Secunia SVCRP) for reporting this issue.
Alvaro Herrera [Fri, 1 Feb 2013 15:00:40 +0000 (12:00 -0300)]
Fix typo in freeze_table_age implementation
The original code used freeze_min_age instead of freeze_table_age. The
main consequence of this mistake is that lowering freeze_min_age would
cause full-table scans to occur much more frequently, which causes
serious issues because the number of writes required is much larger.
That feature (freeze_min_age) is supposed to affect only how soon tuples
are frozen; some pages should still be skipped due to the visibility
map.
Backpatch to 8.4, where the freeze_table_age feature was introduced.
Magnus Hagander [Thu, 31 Jan 2013 14:03:24 +0000 (15:03 +0100)]
Properly zero-pad the day-of-year part of the win32 build number
This ensure the version number increases over time. The first three digits
in the version number is still set to the actual PostgreSQL version
number, but the last one is intended to be an ever increasing build number,
which previosly failed when it changed between 1, 2 and 3 digits long values.
Tom Lane [Thu, 31 Jan 2013 01:02:33 +0000 (20:02 -0500)]
Fix plpgsql's reporting of plan-time errors in possibly-simple expressions.
exec_simple_check_plan and exec_eval_simple_expr attempted to call
GetCachedPlan directly. This meant that if an error was thrown during
planning, the resulting context traceback would not include the line
normally contributed by _SPI_error_callback. This is already inconsistent,
but just to be really odd, a re-execution of the very same expression
*would* show the additional context line, because we'd already have cached
the plan and marked the expression as non-simple.
The problem is easy to demonstrate in 9.2 and HEAD because planning of a
cached plan doesn't occur at all until GetCachedPlan is done. In earlier
versions, it could only be an issue if initial planning had succeeded, then
a replan was forced (already somewhat improbable for a simple expression),
and the replan attempt failed. Since the issue is mainly cosmetic in older
branches anyway, it doesn't seem worth the risk of trying to fix it there.
It is worth fixing in 9.2 since the instability of the context printout can
affect the results of GET STACKED DIAGNOSTICS, as per a recent discussion
on pgsql-novice.
To fix, introduce a SPI function that wraps GetCachedPlan while installing
the correct callback function. Use this instead of calling GetCachedPlan
directly from plpgsql.
Also introduce a wrapper function for extracting a SPI plan's
CachedPlanSource list. This lets us stop including spi_priv.h in
pl_exec.c, which was never a very good idea from a modularity standpoint.
In passing, fix a similar inconsistency that could occur in SPI_cursor_open,
which was also calling GetCachedPlan without setting up a context callback.
Tom Lane [Wed, 30 Jan 2013 19:16:23 +0000 (14:16 -0500)]
Fix grammar for subscripting or field selection from a sub-SELECT result.
Such cases should work, but the grammar failed to accept them because of
our ancient precedence hacks to convince bison that extra parentheses
around a sub-SELECT in an expression are unambiguous. (Formally, they
*are* ambiguous, but we don't especially care whether they're treated as
part of the sub-SELECT or part of the expression. Bison cares, though.)
Fix by adding a redundant-looking production for this case.
This is a fine example of why fixing shift/reduce conflicts via
precedence declarations is more dangerous than it looks: you can easily
cause the parser to reject cases that should work.
This has been wrong since commit 3db4056e22b0c6b2adc92543baf8408d2894fe91
or maybe before, and apparently some people have been working around it
by inserting no-op casts. That method introduces a dump/reload hazard,
as illustrated in bug #7838 from Jan Mate. Hence, back-patch to all
active branches.
Alvaro Herrera [Mon, 28 Jan 2013 20:46:47 +0000 (17:46 -0300)]
DROP OWNED: don't try to drop tablespaces/databases
My "fix" for bugs #7578 and #6116 on DROP OWNED at fe3b5eb08a1 not only
misstated that it applied to REASSIGN OWNED (which it did not affect),
but it also failed to fix the problems fully, because I didn't test the
case of owned shared objects. Thus I created a new bug, reported by
Thomas Kellerer as #7748, which would cause DROP OWNED to fail with a
not-for-user-consumption error message. The code would attempt to drop
the database, which not only fails to work because the underlying code
does not support that, but is a pretty dangerous and undesirable thing
to be doing as well.
This patch fixes that bug by having DROP OWNED only attempt to process
shared objects when grants on them are found, ignoring ownership.
Backpatch to 8.3, which is as far as the previous bug was backpatched.
Tom Lane [Fri, 25 Jan 2013 21:59:00 +0000 (16:59 -0500)]
Fix plpython's handling of functions used as triggers on multiple tables.
plpython tried to use a single cache entry for a trigger function, but it
needs a separate cache entry for each table the trigger is applied to,
because there is table-dependent data in there. This was done correctly
before 9.1, but commit 46211da1b84bc3537e799ee1126098e71c2428e8 broke it
by simplifying the lookup key from "function OID and triggered table OID"
to "function OID and is-trigger boolean". Go back to using both OIDs
as the lookup key. Per bug report from Sandro Santilli.
Tom Lane [Thu, 24 Jan 2013 23:34:04 +0000 (18:34 -0500)]
Fix SPI documentation for new handling of ExecutorRun's count parameter.
Since 9.0, the count parameter has only limited the number of tuples
actually returned by the executor. It doesn't affect the behavior of
INSERT/UPDATE/DELETE unless RETURNING is specified, because without
RETURNING, the ModifyTable plan node doesn't return control to execMain.c
for each tuple. And we only check the limit at the top level.
While this behavioral change was unintentional at the time, discussion of
bug #6572 led us to the conclusion that we prefer the new behavior anyway,
and so we should just adjust the docs to match rather than change the code.
Accordingly, do that. Back-patch as far as 9.0 so that the docs match the
code in each branch.
Simon Riggs [Thu, 24 Jan 2013 14:24:17 +0000 (14:24 +0000)]
Fix rare missing cancellations in Hot Standby.
The machinery around XLOG_HEAP2_CLEANUP_INFO failed
to correctly pass through the necessary information
on latestRemovedXid, avoiding cancellations in some
infrequent concurrent update/cleanup scenarios.
Backpatchable fix to 9.0
Detailed bug report and fix by Noah Misch,
backpatchable version by me.
Tom Lane [Thu, 24 Jan 2013 03:08:01 +0000 (22:08 -0500)]
Fix failure to rotate postmaster log file for size reasons on Windows.
When we eliminated "unnecessary" wakeups of the syslogger process, we
broke size-based logfile rotation on Windows, because on that platform
data transfer is done in a separate thread. While non-Windows platforms
would recheck the output file size after every log message, Windows only
did so when the control thread woke up for some other reason, which might
be quite infrequent. Per bug #7814 from Tsunezumi. Back-patch to 9.2
where the problem was introduced.
Kevin Grittner [Wed, 23 Jan 2013 19:39:28 +0000 (13:39 -0600)]
Fix performance problems with autovacuum truncation in busy workloads.
In situations where there are over 8MB of empty pages at the end of
a table, the truncation work for trailing empty pages takes longer
than deadlock_timeout, and there is frequent access to the table by
processes other than autovacuum, there was a problem with the
autovacuum worker process being canceled by the deadlock checking
code. The truncation work done by autovacuum up that point was
lost, and the attempt tried again by a later autovacuum worker. The
attempts could continue indefinitely without making progress,
consuming resources and blocking other processes for up to
deadlock_timeout each time.
This patch has the autovacuum worker checking whether it is
blocking any other thread at 20ms intervals. If such a condition
develops, the autovacuum worker will persist the work it has done
so far, release its lock on the table, and sleep in 50ms intervals
for up to 5 seconds, hoping to be able to re-acquire the lock and
try again. If it is unable to get the lock in that time, it moves
on and a worker will try to continue later from the point this one
left off.
While this patch doesn't change the rules about when and what to
truncate, it does cause the truncation to occur sooner, with less
blocking, and with the consumption of fewer resources when there is
contention for the table's lock.
The only user-visible change other than improved performance is
that the table size during truncation may change incrementally
instead of just once.
Tom Lane [Mon, 21 Jan 2013 04:43:51 +0000 (23:43 -0500)]
Fix one-byte buffer overrun in PQprintTuples().
This bug goes back to the original Postgres95 sources. Its significance
to modern PG versions is marginal, since we have not used PQprintTuples()
internally in a very long time, and it doesn't seem to have ever been
documented either. Still, it *is* exposed to client apps, so somebody
out there might possibly be using it.
Tom Lane [Sat, 19 Jan 2013 22:20:32 +0000 (17:20 -0500)]
Modernize string literal syntax in tutorial example.
Un-double the backslashes in the LIKE patterns, since
standard_conforming_strings is now the default. Just to be sure, include
a command to set standard_conforming_strings to ON in the example.
Back-patch to 9.1, where standard_conforming_strings became the default.
Andrew Dunstan [Sat, 19 Jan 2013 19:54:29 +0000 (14:54 -0500)]
Make pgxs build executables with the right suffix.
Complaint and patch from Zoltán Böszörményi.
When cross-compiling, the native make doesn't know
about the Windows .exe suffix, so it only builds with
it when explicitly told to do so.
The native make will not see the link between the target
name and the built executable, and might this do unnecesary
work, but that's a bigger problem than this one, if in fact
we consider it a problem at all.
Tom Lane [Fri, 18 Jan 2013 23:06:27 +0000 (18:06 -0500)]
Protect against SnapshotNow race conditions in pg_tablespace scans.
Use of SnapshotNow is known to expose us to race conditions if the tuple(s)
being sought could be updated by concurrently-committing transactions.
CREATE DATABASE and DROP DATABASE are particularly exposed because they do
heavyweight filesystem operations during their scans of pg_tablespace,
so that the scans run for a very long time compared to most. Furthermore,
the potential consequences of a missed or twice-visited row are nastier
than average:
* createdb() could fail with a bogus "file already exists" error, or
silently fail to copy one or more tablespace's worth of files into the
new database.
* remove_dbtablespaces() could miss one or more tablespaces, thus failing
to free filesystem space for the dropped database.
* check_db_file_conflict() could likewise miss a tablespace, leading to an
OID conflict that could result in data loss either immediately or in
future operations. (This seems of very low probability, though, since a
duplicate database OID would be unlikely to start with.)
Hence, it seems worth fixing these three places to use MVCC snapshots, even
though this will someday be superseded by a generic solution to SnapshotNow
race conditions.
Robert Haas [Fri, 18 Jan 2013 16:49:52 +0000 (11:49 -0500)]
Unbreak lock conflict detection for Hot Standby.
This got broken in the original fast-path locking patch, because
I failed to account for the fact that Hot Standby startup process
might take a strong relation lock on a relation in a database to
which it is not bound, and confused MyDatabaseId with the database
ID of the relation being locked.
Report and diagnosis by Andres Freund. Final form of patch by me.
On second thought, use an empty string instead of "none" when not connected.
"none" could mislead to think that you're connected a database with that
name. Also, it needs to be translated, which might be hard without some
context. So in back-branches, use empty string, so that the message is
(currently ""), which is at least unambiguous and doens't require
translation. In master, it's no problem to add translatable strings, so use
a different fix there.
Tom Lane [Mon, 14 Jan 2013 20:19:48 +0000 (15:19 -0500)]
Reject out-of-range dates in to_date().
Dates outside the supported range could be entered, but would not print
reasonably, and operations such as conversion to timestamp wouldn't behave
sanely either. Since this has the potential to result in undumpable table
data, it seems worth back-patching.
Tom Lane [Mon, 14 Jan 2013 19:45:40 +0000 (14:45 -0500)]
Add new timezone abbrevation "FET".
This seems to have been invented in 2011 to represent GMT+3, non daylight
savings rules, as now used in Europe/Kaliningrad and Europe/Minsk.
There are no conflicts so might as well add it to the Default list.
Per bug #7804 from Ruslan Izmaylov.
Andrew Dunstan [Sat, 12 Jan 2013 13:24:38 +0000 (08:24 -0500)]
Extend and improve use of EXTRA_REGRESS_OPTS.
This is now used by ecpg tests, and not clobbered by pg_upgrade
tests. This change won't affect anything that doesn't set this
environment variable, but will enable the buildfarm to control
exactly what port regression test installs will be running on,
and thus to detect possible rogue postmasters more easily.
Backpatch to release 9.2 where EXTRA_REGRESS_OPTS was first used.
Tom Lane [Fri, 11 Jan 2013 18:08:19 +0000 (13:08 -0500)]
Revert ill-considered change of index-size fudge factor.
This partially reverts commit 21a39de5809cd3050a37d2554323cc1d0cbeed9d,
restoring the pre-9.2 cost estimates for index usage. That change
introduced much too large a bias against larger indexes, as per reports
from Jeff Janes and others. The whole thing needs a rewrite, which I've
done in HEAD, but the safest thing to do in 9.2 is just to undo this
multiplier change.
Tom Lane [Tue, 8 Jan 2013 23:26:03 +0000 (18:26 -0500)]
Fix potential corruption of lock table in CREATE/DROP INDEX CONCURRENTLY.
If VirtualXactLock() has to wait for a transaction that holds its VXID lock
as a fast-path lock, it must first convert the fast-path lock to a regular
lock. It failed to take the required "partition" lock on the main
shared-memory lock table while doing so. This is the direct cause of the
assert failure in GetLockStatusData() recently observed in the buildfarm,
but more worryingly it could result in arbitrary corruption of the shared
lock table if some other process were concurrently engaged in modifying the
same partition of the lock table. Fortunately, VirtualXactLock() is only
used by CREATE INDEX CONCURRENTLY and DROP INDEX CONCURRENTLY, so the
opportunities for failure are fewer than they might have been.
In passing, improve some comments and be a bit more consistent about
order of operations.
Tom Lane [Fri, 4 Jan 2013 22:42:25 +0000 (17:42 -0500)]
Invent a "one-shot" variant of CachedPlans for better performance.
SPI_execute() and related functions create a CachedPlan, execute it once,
and immediately discard it, so that the functionality offered by
plancache.c is of no value in this code path. And performance measurements
show that the extra data copying and invalidation checking done by
plancache.c slows down simple queries by 10% or more compared to 9.1.
However, enough of the SPI code is shared with functions that do need plan
caching that it seems impractical to bypass plancache.c altogether.
Instead, let's invent a variant version of cached plans that preserves
99% of the API but doesn't offer any of the actual functionality, nor the
overhead. This puts SPI_execute() performance back on par, or maybe even
slightly better, than it was before. This change should resolve recent
complaints of performance degradation from Dong Ye, Pavel Stehule, and
others.
By avoiding data copying, this change also reduces the amount of memory
needed to execute many-statement SPI_execute() strings, as for instance in
a recent complaint from Tomas Vondra.
An additional benefit of this change is that multi-statement SPI_execute()
query strings are now processed fully serially, that is we complete
execution of earlier statements before running parse analysis and planning
on following ones. This eliminates a long-standing POLA violation, in that
DDL that affects the behavior of a later statement will now behave as
expected.
Back-patch to 9.2, since this was a performance regression compared to 9.1.
(In 9.2, place the added struct fields so as to avoid changing the offsets
of existing fields.)
Tom Lane [Thu, 3 Jan 2013 23:34:57 +0000 (18:34 -0500)]
Prevent creation of postmaster's TCP socket during pg_upgrade testing.
On non-Windows machines, we use the Unix socket for connections to test
postmasters, so there is no need to create a TCP socket. Furthermore,
doing so causes failures due to port conflicts if two builds are carried
out concurrently on one machine. (If the builds are done in different
chroots, which is standard practice at least in Red Hat distros, there
is no risk of conflict on the Unix socket.) Suppressing the TCP socket
by setting listen_addresses to empty has long been standard practice
for pg_regress, and pg_upgrade knows about this too ... but pg_upgrade's
test.sh didn't get the memo.
Back-patch to 9.2, and also sync the 9.2 version of the script with HEAD
as much as practical.
Tolerate timeline switches while "pg_basebackup -X fetch" is running.
If you take a base backup from a standby server with "pg_basebackup -X
fetch", and the timeline switches while the backup is being taken, the
backup used to fail with an error "requested WAL segment %s has already
been removed". This is because the server-side code that sends over the
required WAL files would not construct the WAL filename with the correct
timeline after a switch.
Fix that by using readdir() to scan pg_xlog for all the WAL segments in the
range, regardless of timeline.
Also, include all timeline history files in the backup, if taken with
"-X fetch". That fixes another related bug: If a timeline switch happened
just before the backup was initiated in a standby, the WAL segment
containing the initial checkpoint record contains WAL from the older
timeline too. Recovery will not accept that without a timeline history file
that lists the older timeline.
Backpatch to 9.2. Versions prior to that were not affected as you could not
take a base backup from a standby before 9.2.
Keep timeline history files restored from archive in pg_xlog.
The cascading standby patch in 9.2 changed the way WAL files are treated
when restored from the archive. Before, they were restored under a temporary
filename, and not kept in pg_xlog, but after the patch, they were copied
under pg_xlog. This is necessary for a cascading standby to find them, but
it also means that if the archive goes offline and a standby is restarted,
it can recover back to where it was using the files in pg_xlog. It also
means that if you take an offline backup from a standby server, it includes
all the required WAL files in pg_xlog.
However, the same change was not made to timeline history files, so if the
WAL segment containing the checkpoint record contains a timeline switch, you
will still get an error if you try to restart recovery without the archive,
or recover from an offline backup taken from the standby.
With this patch, timeline history files restored from archive are copied
into pg_xlog like WAL files are, so that pg_xlog contains all the files
required to recover. This is a corner-case pre-existing issue in 9.2, but
even more important in master where it's possible for a standby to follow a
timeline switch through streaming replication. To make that possible, the
timeline history files must be present in pg_xlog.
Tom Lane [Mon, 24 Dec 2012 22:52:27 +0000 (17:52 -0500)]
Fix some minor issues in view pretty-printing.
Code review for commit 2f582f76b1945929ff07116cd4639747ce9bb8a1: don't use
a static variable for what ought to be a deparse_context field, fix
non-multibyte-safe test for spaces, avoid useless and potentially O(N^2)
(though admittedly with a very small constant) calculations of wrap
positions when we aren't going to wrap.
Tom Lane [Sun, 23 Dec 2012 19:07:31 +0000 (14:07 -0500)]
Prevent failure when RowExpr or XmlExpr is parse-analyzed twice.
transformExpr() is required to cope with already-transformed expression
trees, for various ugly-but-not-quite-worth-cleaning-up reasons. However,
some of its newer subroutines hadn't gotten the memo. This accounts for
bug #7763 from Norbert Buchmuller: transformRowExpr() was overwriting the
previously determined type of a RowExpr during CREATE TABLE LIKE INCLUDING
INDEXES. Additional investigation showed that transformXmlExpr had the
same kind of problem, but all the other cases seem to be safe.
Fix race condition if a file is removed while pg_basebackup is running.
If a relation file was removed when the server-side counterpart of
pg_basebackup was just about to open it to send it to the client, you'd
get a "could not open file" error. Fix that.
Backpatch to 9.1, this goes back to when pg_basebackup was introduced.
Tom Lane [Thu, 20 Dec 2012 21:31:04 +0000 (16:31 -0500)]
Fix pg_extension_config_dump() to handle update cases more sanely.
If pg_extension_config_dump() is executed again for a table already listed
in the extension's extconfig, the code was blindly making a new array entry.
This does not seem useful. Fix it to replace the existing array entry
instead, so that it's possible for extension update scripts to alter the
filter conditions for configuration tables.
In addition, teach ALTER EXTENSION DROP TABLE to check for an extconfig
entry for the target table, and remove it if present. This is not a 100%
solution because it's allowed for an extension update script to just
summarily DROP a member table, and that code path doesn't go through
ExecAlterExtensionContentsStmt. We could probably make that case clean
things up if we had to, but it would involve sticking a very ugly wart
somewhere in the guts of dependency.c. Since on the whole it seems quite
unlikely that extension updates would want to remove pre-existing
configuration tables, making the case possible with an explicit command
seems sufficient.
Per bug #7756 from Regina Obe. Back-patch to 9.1 where extensions were
introduced.
Fix recycling of WAL segments after changing recovery target timeline.
After the recovery target timeline is changed, we would still recycle and
preallocate WAL segments on the old target timeline. Those WAL segments
created for the old timeline are a waste of space, although otherwise
harmless.
The problem is that when installing a recycled WAL segment as a future one,
ThisTimeLineID is used to construct the filename. ThisTimeLineID is
initialized in the checkpointer process to the recovery target timeline at
startup, but it was not updated when the startup process chooses a new
target timeline (recovery_target_timeline='latest'). To fix, always update
ThisTimeLineID before recycling WAL segments at a restartpoint.
This still leaves a small window where we might install WAL segments under
wrong timeline ID, if the target timeline is changed just as we're about to
start recycling. Also, when we're not on the target timeline yet, but still
replaying some older timeline, we'll install WAL segments to the newer
timeline anyway and they will still go wasted. We'll just live with the
waste in that situation.
Commit to 9.2 and 9.1. Older versions didn't change recovery target timeline
after startup, and for master, I'll commit a slightly different variant of
this.
Check if we've reached end-of-backup point also if no redo is required.
If you restored from a backup taken from a standby, and the last record in
the backup is the checkpoint record, ie. there is no redo required except
for the checkpoint record, we would fail to notice that we've reached the
end-of-backup point, and the database is consistent. The result was an
error "WAL ends before end of online backup". To fix, move the
have-we-reached-end-of-backup check into CheckRecoveryConsistency(), which
is already responsible for similar checks with minRecoveryPoint, and is
called in the right places.
Backpatch to 9.2, this check and bug did not exist before that.
Tom Lane [Tue, 18 Dec 2012 21:22:19 +0000 (16:22 -0500)]
Ignore libedit/libreadline while probing for standard functions.
Some versions of libedit expose bogus definitions of setproctitle(),
optreset, and perhaps other symbols that we don't want configure to pick up
on. There was a previous report of similar problems with strlcpy(), which
we addressed in commit 59cf88da91bc88978b05275ebd94ac2d980c4047, but the
problem has evidently grown in scope since then. In hopes of not having to
deal with it again in future, rearrange configure's tests for supplied
functions so that we ignore libedit/libreadline except when probing
specifically for functions we expect them to provide.
Per report from Christoph Berg, though this is slightly more aggressive
than his proposed patch.
Tom Lane [Tue, 18 Dec 2012 01:15:39 +0000 (20:15 -0500)]
Fix failure to ignore leftover temp tables after a server crash.
During crash recovery, we remove disk files belonging to temporary tables,
but the system catalog entries for such tables are intentionally not
cleaned up right away. Instead, the first backend that uses a temp schema
is expected to clean out any leftover objects therein. This approach
requires that we be careful to ignore leftover temp tables (since any
actual access attempt would fail), *even if their BackendId matches our
session*, if we have not yet established use of the session's corresponding
temp schema. That worked fine in the past, but was broken by commit debcec7dc31a992703911a9953e299c8d730c778 which incorrectly removed the
rd_islocaltemp relcache flag. Put it back, and undo various changes
that substituted tests like "rel->rd_backend == MyBackendId" for use
of a state-aware flag. Per trouble report from Heikki Linnakangas.
Back-patch to 9.1 where the erroneous change was made. In the back
branches, be careful to add rd_islocaltemp in a spot in the struct that
was alignment padding before, so as not to break existing add-on code.
Tom Lane [Sun, 16 Dec 2012 20:02:02 +0000 (15:02 -0500)]
Fix filling of postmaster.pid in bootstrap/standalone mode.
We failed to ever fill the sixth line (LISTEN_ADDR), which caused the
attempt to fill the seventh line (SHMEM_KEY) to fail, so that the shared
memory key never got added to the file in standalone mode. This has been
broken since we added more content to our lock files in 9.1.
To fix, tweak the logic in CreateLockFile to add an empty LISTEN_ADDR
line in standalone mode. This is a tad grotty, but since that function
already knows almost everything there is to know about the contents of
lock files, it doesn't seem that it's any better to hack it elsewhere.
It's not clear how significant this bug really is, since a standalone
backend should never have any children and thus it seems not critical
to be able to check the nattch count of the shmem segment externally.
But I'm going to back-patch the fix anyway.
This problem had escaped notice because of an ancient (and in hindsight
pretty dubious) decision to suppress LOG-level messages by default in
standalone mode; so that the elog(LOG) complaint in AddToDataDirLockFile
that should have warned of the problem didn't do anything. Fixing that
is material for a separate patch though.
In multi-insert, don't go into infinite loop on a huge tuple and fillfactor.
If a tuple is larger than page size minus space reserved for fillfactor,
heap_multi_insert would never find a page that it fits in and repeatedly ask
for a new page from RelationGetBufferForTuple. If a tuple is too large to
fit on any page, taking fillfactor into account, RelationGetBufferForTuple
will always expand the relation. In a normal insert, heap_insert will accept
that and put the tuple on the new page. heap_multi_insert, however, does a
fillfactor check of its own, and doesn't accept the newly-extended page
RelationGetBufferForTuple returns, even though there is no other choice to
make the tuple fit.
Fix that by making the logic in heap_multi_insert more like the heap_insert
logic. The first tuple is always put on the page RelationGetBufferForTuple
gives us, and the fillfactor check is only applied to the subsequent tuples.
Report from David Gould, although I didn't use his patch.
Tom Lane [Wed, 12 Dec 2012 03:09:12 +0000 (22:09 -0500)]
Add defenses against integer overflow in dynahash numbuckets calculations.
The dynahash code requires the number of buckets in a hash table to fit
in an int; but since we calculate the desired hash table size dynamically,
there are various scenarios where we might calculate too large a value.
The resulting overflow can lead to infinite loops, division-by-zero
crashes, etc. I (tgl) had previously installed some defenses against that
in commit 299d1716525c659f0e02840e31fbe4dea3, but that covered only one
call path. Moreover it worked by limiting the request size to work_mem,
but in a 64-bit machine it's possible to set work_mem high enough that the
problem appears anyway. So let's fix the problem at the root by installing
limits in the dynahash.c functions themselves.
Bruce Momjian [Tue, 11 Dec 2012 20:09:22 +0000 (15:09 -0500)]
Fix pg_upgrade for invalid indexes
All versions of pg_upgrade upgraded invalid indexes caused by CREATE
INDEX CONCURRENTLY failures and marked them as valid. The patch adds a
check to all pg_upgrade versions and throws an error during upgrade or
--check.
Backpatch to 9.2, 9.1, 9.0. Patch slightly adjusted.
Consistency check should compare last record replayed, not last record read.
EndRecPtr is the last record that we've read, but not necessarily yet
replayed. CheckRecoveryConsistency should compare minRecoveryPoint with the
last replayed record instead. This caused recovery to think it's reached
consistency too early.
Now that we do the check in CheckRecoveryConsistency correctly, we have to
move the call of that function to after redoing a record. The current place,
after reading a record but before replaying it, is wrong. In particular, if
there are no more records after the one ending at minRecoveryPoint, we don't
enter hot standby until one extra record is generated and read by the
standby, and CheckRecoveryConsistency is called. These two bugs conspired
to make the code appear to work correctly, except for the small window
between reading the last record that reaches minRecoveryPoint, and
replaying it.
In the passing, rename recoveryLastRecPtr, which is the last record
replayed, to lastReplayedEndRecPtr. This makes it slightly less confusing
with replayEndRecPtr, which is the last record read that we're about to
replay.
Original report from Kyotaro HORIGUCHI, further diagnosis by Fujii Masao.
Backpatch to 9.0, where Hot Standby subtly changed the test from
"minRecoveryPoint < EndRecPtr" to "minRecoveryPoint <= EndRecPtr". The
former works because where the test is performed, we have always read one
more record than we've replayed.
Andrew Dunstan [Tue, 11 Dec 2012 16:52:23 +0000 (11:52 -0500)]
Add mode where contrib installcheck runs each module in a separately named database.
Normally each module is tested in a database named contrib_regression,
which is dropped and recreated at the beginhning of each pg_regress run.
This new mode, enabled by adding USE_MODULE_DB=1 to the make command
line, runs most modules in a database with the module name embedded in
it.
This will make testing pg_upgrade on clusters with the contrib modules
a lot easier.
Second attempt at this, this time accomodating make versions older
than 3.82.
Still to be done: adapt to the MSVC build system.
Backpatch to 9.0, which is the earliest version it is reasonably
possible to test upgrading from.
If a file is truncated, we must update minRecoveryPoint. Once a file is
truncated, there's no going back; it would not be safe to stop recovery
at a point earlier than that anymore.
Per report from Kyotaro HORIGUCHI. Backpatch to 8.4. Before that,
minRecoveryPoint was not updated during recovery at all.
Tom Lane [Sun, 9 Dec 2012 05:08:30 +0000 (00:08 -0500)]
Fix assorted bugs in privileges-for-types patch.
Commit 729205571e81b4767efc42ad7beb53663e08d1ff added privileges on data
types, but there were a number of oversights. The implementation of
default privileges for types missed a few places, and pg_dump was
utterly innocent of the whole concept. Per bug #7741 from Nathan Alden,
and subsequent wider investigation.
Tom Lane [Thu, 6 Dec 2012 04:42:55 +0000 (23:42 -0500)]
Fix intermittent crash in DROP INDEX CONCURRENTLY.
When deleteOneObject closes and reopens the pg_depend relation,
we must see to it that the relcache pointer held by the calling function
(typically performMultipleDeletions) is updated. Usually the relcache
entry is retained so that the pointer value doesn't change, which is why
the problem had escaped notice ... but after a cache flush event there's
no guarantee that the same memory will be reassigned. To fix, change
the recursive functions' APIs so that we pass around a "Relation *"
not just "Relation".
Per investigation of occasional buildfarm failures. This is trivial
to reproduce with -DCLOBBER_CACHE_ALWAYS, which points up the sad
lack of any buildfarm member running that way on a regular basis.
Tom Lane [Wed, 5 Dec 2012 23:27:57 +0000 (18:27 -0500)]
Ensure recovery pause feature doesn't pause unless users can connect.
If we're not in hot standby mode, then there's no way for users to connect
to reset the recoveryPause flag, so we shouldn't pause. The code was aware
of this but the test to see if pausing was safe was seriously inadequate:
it wasn't paying attention to reachedConsistency, and besides what it was
testing was that we could legally enter hot standby, not that we have
done so. Get rid of that in favor of checking LocalHotStandbyActive,
which because of the coding in CheckRecoveryConsistency is tantamount to
checking that we have told the postmaster to enter hot standby.
Also, move the recoveryPausesHere() call that reacts to asynchronous
recoveryPause requests so that it's not in the middle of application of a
WAL record. I put it next to the recoveryStopsHere() call --- in future
those are going to need to interact significantly, so this seems like a
good waystation.
Also, don't bother trying to read another WAL record if we've already
decided not to continue recovery. This was no big deal when the code was
written originally, but now that reading a record might entail actions like
fetching an archive file, it seems a bit silly to do it like that.
Per report from Jeff Janes and subsequent discussion. The pause feature
needs quite a lot more work, but this gets rid of some indisputable bugs,
and seems safe enough to back-patch.
Simon Riggs [Wed, 5 Dec 2012 13:28:39 +0000 (13:28 +0000)]
Must not reach consistency before XLOG_BACKUP_RECORD
When waiting for an XLOG_BACKUP_RECORD the minRecoveryPoint
will be incorrect, so we must not declare recovery as consistent
before we have seen the record. Major bug allowing recovery to end
too early in some cases, allowing people to see inconsistent db.
This patch to HEAD and 9.2, other fix required for 9.1 and 9.0
Simon Riggs and Andres Freund, bug report by Jeff Janes
projects / postgresql / log