Tom Lane [Sat, 15 May 2010 18:11:13 +0000 (18:11 +0000)]
Improve documentation of pg_restore's -l and -L switches to point out their
interactions with filtering switches, such as -n and -t. Per a complaint
from Russell Smith.
Tom Lane [Thu, 13 May 2010 18:29:19 +0000 (18:29 +0000)]
Prevent PL/Tcl from loading the "unknown" module from pltcl_modules unless
that is a regular table or view owned by a superuser. This prevents a
trojan horse attack whereby any unprivileged SQL user could create such a
table and insert code into it that would then get executed in other users'
sessions whenever they call pltcl functions.
Worse yet, because the code was automatically loaded into both the "normal"
and "safe" interpreters at first use, the attacker could execute unrestricted
Tcl code in the "normal" interpreter without there being any pltclu functions
anywhere, or indeed anyone else using pltcl at all: installing pltcl is
sufficient to open the hole. Change the initialization logic so that the
"unknown" code is only loaded into an interpreter when the interpreter is
first really used. (That doesn't add any additional security in this
particular context, but it seems a prudent change, and anyway the former
behavior violated the principle of least astonishment.)
Andrew Dunstan [Thu, 13 May 2010 16:40:36 +0000 (16:40 +0000)]
Abandon the use of Perl's Safe.pm to enforce restrictions in plperl, as it is
fundamentally insecure. Instead apply an opmask to the whole interpreter that
imposes restrictions on unsafe operations. These restrictions are much harder
to subvert than is Safe.pm, since there is no container to be broken out of.
Backported to release 7.4.
In releases 7.4, 8.0 and 8.1 this also includes the necessary backporting of
the two interpreters model for plperl and plperlu adopted in release 8.2.
In versions 8.0 and up, the use of Perl's POSIX module to undo its locale
mangling on Windows has become insecure with these changes, so it is
replaced by our own routine, which is also faster.
Nice side effects of the changes include that it is now possible to use perl's
"strict" pragma in a natural way in plperl, and that perl's $a and
$b variables now work as expected in sort routines, and that function
compilation is significantly faster.
Tim Bunce and Andrew Dunstan, with reviews from Alex Hunsaker and
Alexey Klyukin.
Tom Lane [Tue, 11 May 2010 23:01:33 +0000 (23:01 +0000)]
Update time zone data files to tzdata release 2010j: DST law changes in
Argentina, Australian Antarctic, Bangladesh, Mexico, Morocco, Pakistan,
Palestine, Russia, Syria, Tunisia. Historical corrections for Taiwan.
Tom Lane [Tue, 11 May 2010 22:36:58 +0000 (22:36 +0000)]
Add PKST to the default set of timezone abbreviations.
Per discussion, if we have PKT in there then PKST should be too.
Also, fix mistaken claim that these abbrevs are not known to zic.
Tom Lane [Tue, 11 May 2010 16:42:33 +0000 (16:42 +0000)]
Cause the archiver process to adopt new postgresql.conf settings (particularly
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.
Itagaki Takahiro [Tue, 11 May 2010 04:56:37 +0000 (04:56 +0000)]
Set per-function GUC settings during validating the function.
Now validators work properly even when the settings contain
parameters that affect behavior of the function, like search_path.
Tom Lane [Sat, 8 May 2010 16:40:03 +0000 (16:40 +0000)]
Work around a subtle portability problem in use of printf %s format.
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".
Tom Lane [Wed, 5 May 2010 22:19:05 +0000 (22:19 +0000)]
Fix psql to not go into infinite recursion when expanding a variable that
refers to itself (directly or indirectly). Instead, print a message when
recursion is detected, and don't expand the repeated reference. Per bug
#5448 from Francis Markham.
Back-patch to 8.0. Although the issue exists in 7.4 as well, it seems
impractical to fix there because of the lack of any state stack that
could be used to track active expansions.
Tom Lane [Sun, 2 May 2010 22:28:11 +0000 (22:28 +0000)]
Fix replay of XLOG_HEAP_NEWPAGE WAL records to pay attention to the forknum
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.
Tom Lane [Sat, 1 May 2010 22:46:36 +0000 (22:46 +0000)]
Add code to InternalIpcMemoryCreate() to handle the case where shmget()
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.
Tom Lane [Fri, 30 Apr 2010 19:15:51 +0000 (19:15 +0000)]
Fix multiple memory leaks in PLy_spi_execute_fetch_result: it would leak
memory if the result had zero rows, and also if there was any sort of error
while converting the result tuples into Python data. Reported and partially
fixed by Andres Freund.
Back-patch to all supported versions. Note: I haven't tested the 7.4 fix.
7.4's configure check for python is so obsolete it doesn't work on my
current machines :-(. The logic change is pretty straightforward though.
Robert Haas [Sun, 18 Apr 2010 23:59:55 +0000 (23:59 +0000)]
Provide better guidance for adjusting shared_buffers.
This change was previously committed to HEAD, but the consensus seems to be
in favor of back-patching it. I'm only backpatching as far as 8.3.X, however,
because it's not clear to me to what degree this advice applies to older
branches, and in any case our first advice to anyone attempting to tune those
versions is likely to be "upgrade".
On Windows, syslogger runs in two threads. The main thread processes config
reload and rotation signals, and a helper thread reads messages from the
pipe and writes them to the log file. However, server code isn't generally
thread-safe, so if both try to do e.g palloc()/pfree() at the same time,
bad things will happen. To fix that, use a critical section (which is like
a mutex) to enforce that only one the threads are active at a time.
Tom Lane [Thu, 15 Apr 2010 21:05:11 +0000 (21:05 +0000)]
Fix psql's \copy to not insert spaces around dots and commas in the text of
the SELECT query in \copy (SELECT ...) commands. This is unnecessary and
breaks numeric literals, as seen in bug #5411 from Vitalii Tymchyshyn.
This change has already been made in passing in HEAD; backpatch to 8.2
through 8.4 (earlier releases don't have COPY (SELECT ...) at all).
Tom Lane [Wed, 14 Apr 2010 23:52:16 +0000 (23:52 +0000)]
Fix plpgsql's exec_eval_expr() to ensure it returns a sane type OID
even when the expression is a query that returns no rows.
So far as I can tell, the only caller that actually fails when a garbage
OID is returned is exec_stmt_case(), which is new in 8.4 --- in all other
cases, we might make a useless trip through casting logic, but we won't
fail since the isnull flag will be set. Hence, backpatch only to 8.4,
just in case there are apps out there that aren't expecting an error to
be thrown if the query returns more or less than one column. (Which seems
unlikely, since the error would be thrown if the query ever did return a
row; but it's possible there's some never-exercised code out there.)
Tom Lane [Wed, 14 Apr 2010 21:31:20 +0000 (21:31 +0000)]
Fix a problem introduced by my patch of 2010-01-12 that revised the way
relcache reload works. In the patched code, a relcache entry in process of
being rebuilt doesn't get unhooked from the relcache hash table; which means
that if a cache flush occurs due to sinval queue overrun while we're
rebuilding it, the entry could get blown away by RelationCacheInvalidate,
resulting in crash or misbehavior. Fix by ensuring that an entry being
rebuilt has positive refcount, so it won't be seen as a target for removal
if a cache flush occurs. (This will mean that the entry gets rebuilt twice
in such a scenario, but that's okay.) It appears that the problem can only
arise within a transaction that has previously reassigned the relfilenode of
a pre-existing table, via TRUNCATE or a similar operation. Per bug #5412
from Rusty Conover.
Back-patch to 8.2, same as the patch that introduced the problem.
I think that the failure can't actually occur in 8.2, since it lacks the
rd_newRelfilenodeSubid optimization, but let's make it work like the later
branches anyway.
Magnus Hagander [Thu, 8 Apr 2010 11:26:06 +0000 (11:26 +0000)]
Proceed to look for the next timezone when matching a localized
Windows timezone name where the information in the registry is
incomplete, instead of aborting.
This fixes cases when the registry information is incomplete for
a timezone that is alphabetically before the one that is in use.
Magnus Hagander [Tue, 6 Apr 2010 20:35:17 +0000 (20:35 +0000)]
Log the actual timezone name that we fail to look up the values for in
case the registry data doesn't follow the format we expect, to facilitate
debugging.
Don't pass an invalid file handle to dup2(). That causes a crash on
Windows, thanks to a feature in CRT called Parameter Validation.
Backpatch to 8.2, which is the oldest version supported on Windows. In
8.2 and 8.3 also backpatch the earlier change to use DEVNULL instead of
NULL_DEV #define for a /dev/null-like device. NULL_DEV was hard-coded to
"/dev/null" regardless of platform, which didn't work on Windows, while
DEVNULL works on all platforms. Restarting syslogger didn't work on
Windows on versions 8.3 and below because of that.
Tom Lane [Tue, 30 Mar 2010 21:58:18 +0000 (21:58 +0000)]
Fix "constraint_exclusion = partition" logic so that it will also attempt
constraint exclusion on an inheritance set that is the target of an UPDATE
or DELETE query. Per gripe from Marc Cousin. Back-patch to 8.4 where
the feature was introduced.
Tom Lane [Thu, 25 Mar 2010 15:50:15 +0000 (15:50 +0000)]
Fix ginint4_queryextract() to actually do what it was intended to do for an
unsatisfiable query, such as indexcol && empty_array. It should return -1
to tell GIN no scan is required; but silly typo disabled the logic for that,
resulting in unnecessary "GIN indexes do not support whole-index scans" error.
Per bug report from Jeff Trout.
Alvaro Herrera [Thu, 25 Mar 2010 14:44:51 +0000 (14:44 +0000)]
Prevent ALTER USER f RESET ALL from removing the settings that were put there
by a superuser -- "ALTER USER f RESET setting" already disallows removing such a
setting.
Apply the same treatment to ALTER DATABASE d RESET ALL when run by a database
owner that's not superuser.
Tom Lane [Wed, 24 Mar 2010 17:05:51 +0000 (17:05 +0000)]
Fix thinko in log message for "sameuser" ident map mismatch: the provided
and authenticated usernames were swapped. Reported by Bryan Henderson
in bug #5386.
Also clean up poorly-maintained header comment for this function.
Tom Lane [Sat, 20 Mar 2010 00:58:14 +0000 (00:58 +0000)]
Clear error_context_stack and debug_query_string at the beginning of proc_exit,
so that we won't try to attach any context printouts to messages that get
emitted while exiting. Per report from Dennis Koegel, the context functions
won't necessarily work after we've started shutting down the backend, and it
seems possible that debug_query_string could be pointing at freed storage
as well. The context information doesn't seem particularly relevant to
such messages anyway, so there's little lost by suppressing it.
Back-patch to all supported branches. I can only demonstrate a crash with
log_disconnections messages back to 8.1, but the risk seems real in 8.0 and
before anyway.
Tom Lane [Fri, 19 Mar 2010 22:54:49 +0000 (22:54 +0000)]
Modify error context callback functions to not assume that they can fetch
catalog entries via SearchSysCache and related operations. Although, at the
time that these callbacks are called by elog.c, we have not officially aborted
the current transaction, it still seems rather risky to initiate any new
catalog fetches. In all these cases the needed information is readily
available in the caller and so it's just a matter of a bit of extra notation
to pass it to the callback.
Per crash report from Dennis Koegel. I've concluded that the real fix for
his problem is to clear the error context stack at entry to proc_exit, but
it still seems like a good idea to make the callbacks a bit less fragile
for other cases.
Backpatch to 8.4. We could go further back, but the patch doesn't apply
cleanly. In the absence of proof that this fixes something and isn't just
paranoia, I'm not going to expend the effort.
Fix bug in %r handling in recovery_end_command, it always came out as 0
because InRedo was cleared before recovery_end_command was executed.
Also, always take ControlFileLock when reading checkpoint location for
%r. That didn't matter before, but in 8.4 bgwriter is active during
recovery and can modify the control file concurrently.
Tom Lane [Wed, 17 Mar 2010 15:55:55 +0000 (15:55 +0000)]
Fix incorrect example in CREATE INDEX reference page, per Josh Kupershmidt.
Also fix and uncomment an old example of creating a GIST index, and make
a couple of other minor editorial adjustments.
Tom Lane [Thu, 11 Mar 2010 18:43:32 +0000 (18:43 +0000)]
Sync timezone code with tzcode 2010c from the Olson group. This fixes some
corner cases that come up in certain timezones (apparently, only those with
lots and lots of distinct TZ transition rules, as far as I can gather from
a quick scan of their archives). Per suggestion from Jeevan Chalke.
Back-patch to 8.4. Possibly we need to push this into earlier releases
as well, but I'm hesitant to update them to the 64-bit tzcode without
more thought and testing.
Tom Lane [Tue, 9 Mar 2010 22:34:49 +0000 (22:34 +0000)]
Use SvROK(sv) rather than directly checking SvTYPE(sv) == SVt_RV in plperl.
The latter is considered unwarranted chumminess with the implementation,
and can lead to crashes with recent Perl versions.
Report and fix by Tim Bunce. Back-patch to all versions containing the
questionable coding pattern.
Bruce Momjian [Tue, 9 Mar 2010 01:10:23 +0000 (01:10 +0000)]
Return proper exit code (3) from psql when ON_ERROR_STOP=on and
--single-transaction are both used and the failure happens in commit,
e.g. failed deferred trigger. Also properly free BEGIN/COMMIT result
structures from --single-transaction.
Tom Lane [Sat, 6 Mar 2010 23:10:50 +0000 (23:10 +0000)]
Fix warning messages in restrict_and_check_grant() to include the column name
when warning about column-level privileges. This is more useful than before
and makes the apparent duplication complained of by Piyush Newe not so
duplicate. Also fix lack of quote marks in a related message text.
Back-patch to 8.4, where column-level privileges were introduced.
Tom Lane [Sat, 6 Mar 2010 00:45:55 +0000 (00:45 +0000)]
When reading pg_hba.conf and similar files, do not treat @file as an inclusion
unless (1) the @ isn't quoted and (2) the filename isn't empty. This guards
against unexpectedly treating usernames or other strings in "flat files"
as inclusion requests, as seen in a recent trouble report from Ed L.
The empty-filename case would be guaranteed to misbehave anyway, because our
subsequent path-munging behavior results in trying to read the directory
containing the current input file.
I think this might finally explain the report at
http://archives.postgresql.org/pgsql-bugs/2004-05/msg00132.php
of a crash after printing "authentication file token too long, skipping",
since I was able to duplicate that message (though not a crash) on a
platform where stdio doesn't refuse to read directories. We never got
far in investigating that problem, but now I'm suspicious that the trigger
condition was an @ in the flat password file.
Back-patch to all active branches since the problem can be demonstrated in all
branches except HEAD. The test case, creating a user named "@", doesn't cause
a problem in HEAD since we got rid of the flat password file. Nonetheless it
seems like a good idea to not consider quoted @ as a file inclusion spec,
so I changed HEAD too.
Tom Lane [Wed, 3 Mar 2010 20:31:16 +0000 (20:31 +0000)]
Fix a couple of places that would loop forever if attempts to read a stdio file
set ferror() but never set feof(). This is known to be the case for recent
glibc when trying to read a directory as a file, and might be true for other
platforms/cases too. Per report from Ed L. (There is more that we ought to
do about his report, but this is one easily identifiable issue.)
Tom Lane [Wed, 3 Mar 2010 19:10:29 +0000 (19:10 +0000)]
Make contrib/xml2 use core xml.c's error handler, when available (that is,
in versions >= 8.3). The core code is more robust and efficient than what
was there before, and this also reduces risks involved in swapping different
libxml error handler settings.
Before 8.3, there is still some risk of problems if add-on modules such as
Perl invoke libxml without setting their own error handler. Given the lack
of reports I'm not sure there's a risk in practice, so I didn't take the
step of actually duplicating the core code into older contrib/xml2 branches.
Instead I just tweaked the existing code to ensure it didn't leave a dangling
pointer to short-lived memory when throwing an error.
Tom Lane [Wed, 3 Mar 2010 17:29:53 +0000 (17:29 +0000)]
Export xml.c's libxml-error-handling support so that contrib/xml2 can use it
too, instead of duplicating the functionality (badly).
I renamed xml_init to pg_xml_init, because the former seemed just a bit too
generic to be safe as a global symbol. I considered likewise renaming
xml_ereport to pg_xml_ereport, but felt that the reference to ereport probably
made it sufficiently PG-centric already.
Fix numericlocale psql option when used with a null string and latex and troff
formats; a null string must not be formatted as a numeric. The more exotic
formats latex and troff also incorrectly formatted all strings as numerics
when numericlocale was on.
Backpatch to 8.1 where numericlocale option was added.
Tom Lane [Mon, 1 Mar 2010 18:08:07 +0000 (18:08 +0000)]
Fix contrib/xml2 so regression test still works when it's built without libxslt.
This involves modifying the module to have a stable ABI, that is, the
xslt_process() function still exists even without libxslt. It throws a
runtime error if called, but doesn't prevent executing the CREATE FUNCTION
call. This is a good thing anyway to simplify cross-version upgrades.
Tom Lane [Mon, 1 Mar 2010 05:16:40 +0000 (05:16 +0000)]
Remove xmlCleanupParser calls from contrib/xml2.
These are unnecessary and probably dangerous. I don't see any immediate
risk situations in the core XML support or contrib/xml2 itself, but there
could be issues with external uses of libxml2, and in any case it's an
accident waiting to happen.
Tom Lane [Mon, 1 Mar 2010 03:41:04 +0000 (03:41 +0000)]
Back-patch today's memory management fixups in contrib/xml2.
Prior to 8.3, these changes are not critical for compatibility with core
Postgres, since core had no libxml2 calls then. However there is still
a risk if contrib/xml2 is used along with libxml2 functionality in Perl
or other loadable modules. So back-patch to all versions.
Also back-patch addition of regression tests. I'm not sure how many of
the cases are interesting without the interaction with core xml code,
but a silly regression test is still better than none at all.
Tom Lane [Thu, 25 Feb 2010 21:00:03 +0000 (21:00 +0000)]
Allow predicate_refuted_by() to deduce that NOT A refutes A.
We had originally made the stronger assumption that NOT A refutes any B
if B implies A, but this fails in three-valued logic, because we need to
prove B is false not just that it's not true. However the logic does
go through if B is equal to A.
Recognizing this limited case is enough to handle examples that arise when
we have simplified "bool_var = true" or "bool_var = false" to just "bool_var"
or "NOT bool_var". If we had not done that simplification then the
btree-operator proof logic would have been able to prove that the expressions
were contradictory, but only for identical expressions being compared to the
constants; so handling identical A and B covers all the same cases.
The motivation for doing this is to avoid unexpected asymmetrical behavior
when a partitioned table uses a boolean partitioning column, as in today's
gripe from Dominik Sander.
Back-patch to 8.2, which is as far back as predicate_refuted_by attempts to
do anything at all with NOTs.
Magnus Hagander [Thu, 25 Feb 2010 13:26:26 +0000 (13:26 +0000)]
Add configuration parameter ssl_renegotiation_limit to control
how often we do SSL session key renegotiation. Can be set to
0 to disable renegotiation completely, which is required if
a broken SSL library is used (broken patches to CVE-2009-3555
a known cause) or when using a client library that can't do
renegotiation.
Tom Lane [Wed, 24 Feb 2010 18:02:30 +0000 (18:02 +0000)]
Allow zero-dimensional (ie, empty) arrays in contrib/ltree operations.
The main motivation for changing this is bug #4921, in which it's pointed out
that it's no longer safe to apply ltree operations to the result of
ARRAY(SELECT ...) if the sub-select might return no rows. Before 8.3,
the ARRAY() construct would return NULL, which might or might not be helpful
but at least it wouldn't result in an error. Now it returns an empty array
which results in a failure for no good reason, since the ltree operations
are all perfectly capable of dealing with zero-element arrays.
As far as I can find, these ltree functions are the only places where zero
array dimensionality is rejected unnecessarily.
Back-patch to 8.3 to prevent behavioral regression of queries that worked
in older releases.
Itagaki Takahiro [Fri, 19 Feb 2010 01:04:39 +0000 (01:04 +0000)]
Fix STOP WAL LOCATION in backup history files no to return the next
segment of XLOG_BACKUP_END record even if the the record is placed
at a segment boundary. Furthermore the previous implementation could
return nonexistent segment file name when the boundary is in segments
that has "FE" suffix; We never use segments with "FF" suffix.
Backpatch to 8.0, where hot backup was introduced.
Tom Lane [Thu, 18 Feb 2010 23:50:12 +0000 (23:50 +0000)]
Volatile-ize all five places where we expect a PG_TRY block to restore
old memory context in plpython. Before only one of them was marked
volatile, but per report from Zdenek Kotala, some compilers do the
wrong thing here.
Tom Lane [Thu, 18 Feb 2010 22:43:39 +0000 (22:43 +0000)]
Provide some rather hokey ways for EXPLAIN to print FieldStore and assignment
ArrayRef expressions that are not in the immediate context of an INSERT or
UPDATE targetlist. Such cases never arise in stored rules, so ruleutils.c
hadn't tried to handle them. However, they do occur in the targetlists of
plans derived from such statements, and now that EXPLAIN VERBOSE tries to
print targetlists, we need some way to deal with the case.
I chose to represent an assignment ArrayRef as "array[subscripts] := source",
which is fairly reasonable and doesn't omit any information. However,
FieldStore is problematic because the planner will fold multiple assignments
to fields of the same composite column into one FieldStore, resulting in a
structure that is hard to understand at all, let alone display comprehensibly.
So in that case I punted and just made it print the source expression(s).
Backpatch to 8.4 --- the lack of functionality exists in older releases,
but doesn't seem to be important for lack of anything that would call it.
Tom Lane [Thu, 18 Feb 2010 18:41:55 +0000 (18:41 +0000)]
Fix ExecEvalArrayRef to pass down the old value of the array element or slice
being assigned to, in case the expression to be assigned is a FieldStore that
would need to modify that value. The need for this was foreseen some time
ago, but not implemented then because we did not have arrays of composites.
Now we do, but the point evidently got overlooked in that patch. Net result
is that updating a field of an array element doesn't work right, as
illustrated if you try the new regression test on an unpatched backend.
Noted while experimenting with EXPLAIN VERBOSE, which has also got some issues
in this area.
Backpatch to 8.3, where arrays of composites were introduced.
Tom Lane [Thu, 18 Feb 2010 03:06:53 +0000 (03:06 +0000)]
Force READY portals into FAILED state when a transaction or subtransaction
is aborted, if they were created within the failed xact. This prevents
ExecutorEnd from being run on them, which is a good idea because they may
contain references to tables or other objects that no longer exist.
In particular this is hazardous when auto_explain is active, but it's
really rather surprising that nobody has seen an issue with this before.
I'm back-patching this to 8.4, since that's the first version that contains
auto_explain or an ExecutorEnd hook, but I wonder whether we shouldn't
back-patch further.
Joe Conway [Wed, 3 Feb 2010 23:01:23 +0000 (23:01 +0000)]
Check to ensure the number of primary key fields supplied does not
exceed the total number of non-dropped source table fields for
dblink_build_sql_*(). Addresses bug report from Rushabh Lathia.