Move WAL continuation record information to WAL page header.
The continuation record only contained one field, xl_rem_len, so it makes
things simpler to just include it in the WAL page header. This wastes four
bytes on pages that don't begin with a continuation from previos page, plus
four bytes on every page, because of padding.
The motivation of this is to make it easier to calculate how much space a
WAL record needs. Before this patch, it depended on how many page boundaries
the record crosses. The motivation of that, in turn, is to separate the
allocation of space in the WAL from the copying of the record data to the
allocated space. Keeping the calculation of space required simple helps to
keep the critical section of allocating the space from WAL short. But that's
not included in this patch yet.
Bump WAL version number again, as this is an incompatible change.
Don't waste the last segment of each 4GB logical log file.
The comments claimed that wasting the last segment made it easier to do
calculations with XLogRecPtrs, because you don't have problems representing
last-byte-position-plus-1 that way. In my experience, however, it only made
things more complicated, because the there was two ways to represent the
boundary at the beginning of a logical log file: logid = n+1 and xrecoff = 0,
or as xlogid = n and xrecoff = 4GB - XLOG_SEG_SIZE. Some functions were
picky about which representation was used.
Also, use a 64-bit segment number instead of the log/seg combination, to
point to a certain WAL segment. We assume that all platforms have a working
64-bit integer type nowadays.
This is an incompatible change in WAL format, so bumping WAL version number.
Tom Lane [Thu, 21 Jun 2012 21:26:07 +0000 (17:26 -0400)]
Fix memory leak in ARRAY(SELECT ...) subqueries.
Repeated execution of an uncorrelated ARRAY_SUBLINK sub-select (which
I think can only happen if the sub-select is embedded in a larger,
correlated subquery) would leak memory for the duration of the query,
due to not reclaiming the array generated in the previous execution.
Per bug #6698 from Armando Miraglia. Diagnosis and fix idea by Heikki,
patch itself by me.
This has been like this all along, so back-patch to all supported versions.
Add a small cache of locks owned by a resource owner in ResourceOwner.
This speeds up reassigning locks to the parent owner, when the transaction
holds a lot of locks, but only a few of them belong to the current resource
owner. This is particularly helps pg_dump when dumping a large number of
objects.
The cache can hold up to 15 locks in each resource owner. After that, the
cache is marked as overflowed, and we fall back to the old method of
scanning the whole local lock table. The tradeoff here is that the cache has
to be scanned whenever a lock is released, so if the cache is too large,
lock release becomes more expensive. 15 seems enough to cover pg_dump, and
doesn't have much impact on lock release.
Jeff Janes, reviewed by Amit Kapila and Heikki Linnakangas.
Tom Lane [Thu, 21 Jun 2012 00:15:02 +0000 (20:15 -0400)]
Remove incomplete/incorrect support for zero-column foreign keys.
The original coding in ri_triggers.c had partial support for the concept of
zero-column foreign key constraints. But this is not defined in the SQL
standard, nor was it ever allowed by any other part of Postgres, nor was it
very fully implemented even here (eg there was no support for preventing
PK-table deletions that would violate the constraint). Doesn't seem very
useful to carry 100-plus lines of code for a corner case that no one is
interested in making work. Instead, just add a check that the column list
read from pg_constraint is non-empty.
Tom Lane [Wed, 20 Jun 2012 23:47:37 +0000 (19:47 -0400)]
Increase MAX_SYSCACHE_CALLBACKS from 20 to 32.
By my count there are 18 callers of CacheRegisterSyscacheCallback in the
core code in HEAD, so we are potentially leaving as few as 2 slots for any
add-on code to use (though possibly not all these callers would actually
activate in any particular session). That doesn't seem like a lot of
headroom, so let's pump it up a little.
Tom Lane [Wed, 20 Jun 2012 21:24:14 +0000 (17:24 -0400)]
Cache the results of ri_FetchConstraintInfo in a backend-local cache.
Extracting data from pg_constraint turned out to take as much as 10% of the
runtime in a bulk-update case where the foreign key column wasn't changing,
because we did it over again for each tuple. Fix that by maintaining a
backend-local cache of the results. This is really a pretty small patch,
but converting the trigger functions to work with pointers rather than
local struct variables requires a lot of mechanical changes.
Tom Lane [Wed, 20 Jun 2012 00:07:08 +0000 (20:07 -0400)]
Improve tests for whether we can skip queueing RI enforcement triggers.
During an update of a PK row, we can skip firing the RI trigger if any old
key value is NULL, because then the row could not have had any matching
rows in the FK table. Conversely, during an update of an FK row, the
outcome is determined if any new key value is NULL. In either case it
becomes unnecessary to compare individual key values.
This patch was inspired by discussion of Vik Reykja's patch to use IS NOT
DISTINCT semantics for the key comparisons. In the event there is no need
for that and so this patch looks nothing like his, but he should still get
credit for having re-opened consideration of the trigger skip logic.
Tom Lane [Tue, 19 Jun 2012 22:33:59 +0000 (18:33 -0400)]
Add pgbench option to add foreign key constraints to the standard scenario.
The option --foreign-keys, used at initialization time, will create foreign
key constraints for the columns that represent references to other tables'
primary keys. This can help in benchmarking FK performance.
Tom Lane [Tue, 19 Jun 2012 18:31:54 +0000 (14:31 -0400)]
Share RI trigger code between NO ACTION and RESTRICT cases.
These triggers are identical except for whether ri_Check_Pk_Match is to be
called, so factor out the common code to save a couple hundred lines.
Also, eliminate null-column checks in ri_Check_Pk_Match, since they're
duplicate with the calling functions and require unnecessary complication
in its API statement.
Simplify the way code is shared between RI_FKey_check_ins and
RI_FKey_check_upd, too.
Tom Lane [Tue, 19 Jun 2012 02:45:07 +0000 (22:45 -0400)]
Improve comments about why SET DEFAULT triggers must recheck for matches.
I was confused about this, so try to make it clearer for the next person.
(This seems like a fairly inefficient way of dealing with a corner case,
but I don't have a better idea offhand. Maybe if there were a way to turn
off the RI_FKey_keyequal_upd_fk event filter temporarily?)
Tom Lane [Mon, 18 Jun 2012 23:37:23 +0000 (19:37 -0400)]
Allow ON UPDATE/DELETE SET DEFAULT plans to be cached.
Once upon a time, somebody was worried that cached RI plans wouldn't get
remade with new default values after ALTER TABLE ... SET DEFAULT, so they
didn't allow caching of plans for ON UPDATE/DELETE SET DEFAULT actions.
That time is long gone, though (and even at the time I doubt this was the
greatest hazard posed by ALTER TABLE...). So allow these triggers to cache
their plans just like the others.
The cache_plan argument to ri_PlanCheck is now vestigial, since there
are no callers that don't pass "true"; but I left it alone in case there
is any future need for it.
Tom Lane [Mon, 18 Jun 2012 22:50:03 +0000 (18:50 -0400)]
Remove derived fields from RI_QueryKey, and do a bit of other cleanup.
We really only need the foreign key constraint's OID and the query type
code to uniquely identify each plan we are caching for FK checks. The
other stuff that was in the struct had no business being used as part of
a hash key, and was all just being copied from struct RI_ConstraintInfo
anyway. Get rid of the unnecessary fields, and readjust various function
APIs to make them use RI_ConstraintInfo not RI_QueryKey as info source.
I'd be surprised if this makes any measurable performance difference,
but it certainly feels cleaner.
Tom Lane [Mon, 18 Jun 2012 16:19:38 +0000 (12:19 -0400)]
Update SQL spec references in ri_triggers code to match SQL:2008.
Now that what we're implementing isn't SQL92, we probably shouldn't cite
chapter and verse in that spec anymore. Also fix some comments that
talked about MATCH FULL but in fact were in code that's also used for
MATCH SIMPLE.
Tom Lane [Mon, 18 Jun 2012 16:12:52 +0000 (12:12 -0400)]
Change ON UPDATE SET NULL/SET DEFAULT referential actions to meet SQL spec.
Previously, when executing an ON UPDATE SET NULL or SET DEFAULT action for
a multicolumn MATCH SIMPLE foreign key constraint, we would set only those
referencing columns corresponding to referenced columns that were changed.
This is what the SQL92 standard said to do --- but more recent versions
of the standard say that all referencing columns should be set to null or
their default values, no matter exactly which referenced columns changed.
At least for SET DEFAULT, that is clearly saner behavior. It's somewhat
debatable whether it's an improvement for SET NULL, but it appears that
other RDBMS systems read the spec this way. So let's do it like that.
This is a release-notable behavioral change, although considering that
our documentation already implied it was done this way, the lack of
complaints suggests few people use such cases.
Tom Lane [Mon, 18 Jun 2012 00:16:07 +0000 (20:16 -0400)]
Refer to the default foreign key match style as MATCH SIMPLE internally.
Previously we followed the SQL92 wording, "MATCH <unspecified>", but since
SQL99 there's been a less awkward way to refer to the default style.
In addition to the code changes, pg_constraint.confmatchtype now stores
this match style as 's' (SIMPLE) rather than 'u' (UNSPECIFIED). This
doesn't affect pg_dump or psql because they use pg_get_constraintdef()
to reconstruct foreign key definitions. But other client-side code might
examine that column directly, so this change will have to be marked as
an incompatibility in the 9.3 release notes.
Peter Eisentraut [Sun, 17 Jun 2012 23:44:00 +0000 (02:44 +0300)]
Make documentation of --help and --version options more consistent
Before, some places didn't document the short options (-? and -V),
some documented both, some documented nothing, and they were listed in
various orders. Now this is hopefully more consistent and complete.
Tom Lane [Sun, 17 Jun 2012 21:11:07 +0000 (17:11 -0400)]
Fix stats collector to recover nicely when system clock goes backwards.
Formerly, if the system clock went backwards, the stats collector would
fail to update the stats file any more until the clock reading again
exceeds whatever timestamp was last written into the stats file. Such
glitches in the clock's behavior are not terribly unlikely on machines
not using NTP. Such a scenario has been observed to cause regression test
failures in the buildfarm, and it could have bad effects on the behavior
of autovacuum, so it seems prudent to install some defenses.
We could directly detect the clock going backwards by adding
GetCurrentTimestamp calls in the stats collector's main loop, but that
would hurt performance on platforms where GetCurrentTimestamp is expensive.
To minimize the performance hit in normal cases, adopt a more complicated
scheme wherein backends check for clock skew when reading the stats file,
and if they see it, signal the stats collector by sending an extra stats
inquiry message. The stats collector does an extra GetCurrentTimestamp
only when it receives an inquiry with an apparently out-of-order
timestamp.
To avoid unnecessary GetCurrentTimestamp calls, expand the inquiry messages
to carry the backend's current clock reading as well as its stats cutoff
time. The latter, being intentionally slightly in-the-past, would trigger
more clock rechecks than we need if it were used for this purpose.
We might want to backpatch this change at some point, but let's let it
shake out in the buildfarm for awhile first.
Peter Eisentraut [Fri, 15 Jun 2012 19:55:03 +0000 (22:55 +0300)]
Improve reporting of permission errors for array types
Because permissions are assigned to element types, not array types,
complaining about permission denied on an array type would be
misleading to users. So adjust the reporting to refer to the element
type instead.
In order not to duplicate the required logic in two dozen places,
refactor the permission denied reporting for types a bit.
pointed out by Yeb Havinga during the review of the type privilege
feature
Robert Haas [Thu, 14 Jun 2012 14:19:33 +0000 (10:19 -0400)]
During transaction cleanup, release locks before deleting files.
There's no need to hold onto the locks until the files are needed,
and by doing it this way, we reduce the impact on other backends who
may be awaiting locks we hold.
Robert Haas [Thu, 14 Jun 2012 14:11:16 +0000 (10:11 -0400)]
Add new function log_newpage_buffer.
When I implemented the ginbuildempty() function as part of
implementing unlogged tables, I falsified the note in the header
comment for log_newpage. Although we could fix that up by changing
the comment, it seems cleaner to add a new function which is
specifically intended to handle this case. So do that.
Robert Haas [Thu, 14 Jun 2012 13:58:53 +0000 (09:58 -0400)]
Remove misplaced sanity check from heap_create().
Even when allow_system_table_mods is not set, we allow creation of any
type of SQL object in pg_catalog, except for relations. And you can
get relations into pg_catalog, too, by initially creating them in some
other schema and then moving them with ALTER .. SET SCHEMA. So this
restriction, which prevents relations (only) from being created in
pg_catalog directly, is fairly pointless. If we need a safety mechanism
for this, it should be placed further upstream, so that it affects all
SQL objects uniformly, and picks up both CREATE and SET SCHEMA.
For now, just rip it out, per discussion with Tom Lane.
Tom Lane [Thu, 14 Jun 2012 02:06:26 +0000 (22:06 -0400)]
Stamp library minor versions for 9.3.
This includes fixing the MSVC copy of ecpg/preproc's version info, which
seems to have been overlooked repeatedly. Can't we fix that so there are
not two copies??
Tom Lane [Wed, 13 Jun 2012 23:43:35 +0000 (19:43 -0400)]
Revisit error message details for JSON input parsing.
Instead of identifying error locations only by line number (which could
be entirely unhelpful with long input lines), provide a fragment of the
input text too, placing this info in a new CONTEXT entry. Make the
error detail messages conform more closely to style guidelines, fix
failure to expose some of them for translation, ensure compiler can
check formats against supplied parameters.
Tom Lane [Wed, 13 Jun 2012 22:17:09 +0000 (18:17 -0400)]
Revert "Reduce checkpoints and WAL traffic on low activity database server"
This reverts commit 18fb9d8d21a28caddb72c7ffbdd7b96d52ff9724. Per
discussion, it does not seem like a good idea to allow committed changes to
go un-checkpointed indefinitely, as could happen in a low-traffic server;
that makes us entirely reliant on the WAL stream with no redundancy that
might aid data recovery in case of disk failure.
This re-introduces the original problem of hot-standby setups generating a
small continuing stream of WAL traffic even when idle, but there are other
ways to address that without compromising crash recovery, so we'll revisit
that issue in a future release cycle.
Tom Lane [Wed, 13 Jun 2012 21:48:42 +0000 (17:48 -0400)]
Deprecate use of GLOBAL and LOCAL in temp table creation.
Aside from adjusting the documentation to say that these are deprecated,
we now report a warning (not an error) for use of GLOBAL, since it seems
fairly likely that we might change that to request SQL-spec-compliant temp
table behavior in the foreseeable future. Although our handling of LOCAL
is equally nonstandard, there is no evident interest in ever implementing
SQL modules, and furthermore some other products interpret LOCAL as
behaving the same way we do. So no expectation of change and no warning
for LOCAL; but it still seems a good idea to deprecate writing it.
Tom Lane [Wed, 13 Jun 2012 19:34:57 +0000 (15:34 -0400)]
Support Linux's oom_score_adj API as well as the older oom_adj API.
The simplest way to handle this is just to copy-and-paste the relevant
code block in fork_process.c, so that's what I did. (It's possible that
something more complicated would be useful to packagers who want to work
with either the old or the new API; but at this point the number of such
people is rapidly approaching zero, so let's just get the minimal thing
done.) Update relevant documentation as well.
Robert Haas [Tue, 12 Jun 2012 13:51:48 +0000 (09:51 -0400)]
Copy-editing of release notes.
Remove a couple of items that were actually back-patched bug fixes.
Add additional details to a couple of items which lacked a description.
Improve attributions for a couple of items I was involved with.
A few other miscellaneous corrections.
Tom Lane [Tue, 12 Jun 2012 02:47:16 +0000 (22:47 -0400)]
Ensure pg_ctl behaves sanely when data directory is not specified.
Commit aaa6e1def292cdacb6b27088898793b1b879fedf introduced multiple hazards
in the case where pg_ctl is executed with neither a -D switch nor any
PGDATA environment variable. It would dump core on machines which are
unforgiving about printf("%s", NULL), or failing that possibly give a
rather unhelpful complaint about being unable to execute "postgres -C",
rather than the logically prior complaint about not being told where the
data directory is.
Edmund Horner's report suggests that there is another, Windows-specific
hazard here, but I'm not the person to fix that; it would in any case only
be significant when trying to use a config-only PGDATA pointer.
Tom Lane [Tue, 12 Jun 2012 01:55:48 +0000 (21:55 -0400)]
Fix pg_dump output to a named tar-file archive.
"pg_dump -Ft -f filename ..." got broken by my recent commit 4317e0246c645f60c39e6572644cff1cb03b4c65, which I fear I only tested
in the output-to-stdout variant.
Magnus Hagander [Mon, 11 Jun 2012 13:07:55 +0000 (15:07 +0200)]
Prevent non-streaming replication connections from being selected sync slave
This prevents a pg_basebackup backup session that just does a base
backup (no xlog involved at all) from becoming the synchronous slave
and thus blocking all access while it runs.
Also fixes the problem when a higher priority slave shows up it would
become the sync standby before it has reached the STREAMING state, by
making sure we can only switch to a walsender that's actually STREAMING.
Simon Riggs [Fri, 8 Jun 2012 16:34:04 +0000 (17:34 +0100)]
Fix bug in early startup of Hot Standby with subtransactions.
When HS startup is deferred because of overflowed subtransactions, ensure
that we re-initialize KnownAssignedXids for when both existing and incoming
snapshots have non-zero qualifying xids.
Fixes bug #6661 reported by Valentine Gogichashvili.
Tom Lane [Thu, 7 Jun 2012 21:42:27 +0000 (17:42 -0400)]
Scan the buffer pool just once, not once per fork, during relation drop.
This provides a speedup of about 4X when NBuffers is large enough.
There is also a useful reduction in sinval traffic, since we
only do CacheInvalidateSmgr() once not once per fork.
Simon Riggs, reviewed and somewhat revised by Tom Lane
Tom Lane [Thu, 7 Jun 2012 20:46:26 +0000 (16:46 -0400)]
Do unlocked prechecks in bufmgr.c loops that scan the whole buffer pool.
DropRelFileNodeBuffers, DropDatabaseBuffers, FlushRelationBuffers, and
FlushDatabaseBuffers have to scan the whole shared_buffers pool because
we have no index structure that would find the target buffers any more
efficiently than that. This gets expensive with large NBuffers. We can
shave some cycles from these loops by prechecking to see if the current
buffer is interesting before we acquire the buffer header lock.
Ordinarily such a test would be unsafe, but in these cases it should be
safe because we are already assuming that the caller holds a lock that
prevents any new target pages from being loaded into the buffer pool
concurrently. Therefore, no buffer tag should be changing to a value of
interest, only away from a value of interest. So a false negative match
is impossible, while a false positive is safe because we'll recheck after
acquiring the buffer lock. Initial testing says that this speeds these
loops by a factor of 2X to 3X on common Intel hardware.
Patch for DropRelFileNodeBuffers by Jeff Janes (based on an idea of
Heikki's); extended to the remaining sequential scans by Tom Lane
Simon Riggs [Thu, 7 Jun 2012 18:22:47 +0000 (19:22 +0100)]
Wake WALSender to reduce data loss at failover for async commit.
WALSender now woken up after each background flush by WALwriter, avoiding
multi-second replication delay for an all-async commit workload.
Replication delay reduced from 7s with default settings to 200ms and often
much less, allowing significantly reduced data loss at failover.
Robert Haas [Thu, 7 Jun 2012 16:25:41 +0000 (12:25 -0400)]
Fix more crash-safe visibility map bugs, and improve comments.
In lazy_scan_heap, we could issue bogus warnings about incorrect
information in the visibility map, because we checked the visibility
map bit before locking the heap page, creating a race condition. Fix
by rechecking the visibility map bit before we complain. Rejigger
some related logic so that we rely on the possibly-outdated
all_visible_according_to_vm value as little as possible.
In heap_multi_insert, it's not safe to clear the visibility map bit
before beginning the critical section. The visibility map is not
crash-safe unless we treat clearing the bit as a critical operation.
Specifically, if the transaction were to error out after we set the
bit and before entering the critical section, we could end up writing
the heap page to disk (with the bit cleared) and crashing before the
visibility map page made it to disk. That would be bad. heap_insert
has this correct, but somehow the order of operations got rearranged
when heap_multi_insert was added.
Also, add some more comments to visibilitymap_test, lazy_scan_heap,
and IndexOnlyNext, expounding on concurrency issues.
Per extensive code review by Andres Freund, and further review by Tom
Lane, who also made the original report about the bogus warnings.
Tom Lane [Tue, 5 Jun 2012 00:43:57 +0000 (20:43 -0400)]
Fix bogus handling of control characters in json_lex_string().
The original coding misbehaved if "char" is signed, and also made the
extremely poor decision to print control characters literally when trying
to complain about them. Report and patch by Shigeru Hanada.
In passing, also fix core dump risk in report_parse_error() should the
parse state be something other than what it expects.
Tom Lane [Tue, 5 Jun 2012 00:12:50 +0000 (20:12 -0400)]
Fix some more bugs in contrib/xml2's xslt_process().
It failed to check for error return from xsltApplyStylesheet(), as reported
by Peter Gagarinov. (So far as I can tell, libxslt provides no convenient
way to get a useful error message in failure cases. There might be some
inconvenient way, but considering that this code is deprecated it's hard to
get enthusiastic about putting lots of work into it. So I just made it say
"failed to apply stylesheet", in line with the existing error checks.)
While looking at the code I also noticed that the string returned by
xsltSaveResultToString was never freed, resulting in a session-lifespan
memory leak.
Tom Lane [Sun, 3 Jun 2012 15:52:52 +0000 (11:52 -0400)]
Fix memory leaks in failure paths in buildACLCommands and parseAclItem.
This is currently only cosmetic, since all the call sites just curl up
and die in event of a failure return. It might be important for some
future use-case, though, and in any case it quiets warnings from the
clang static analyzer (as reported by Anna Zaks).
Bruce Momjian [Fri, 1 Jun 2012 15:40:04 +0000 (11:40 -0400)]
In pg_upgrade, report pre-PG 8.1 plpython helper functions left in the
public schema that no longer point to valid shared object libraries, and
suggest a solution.
Simon Riggs [Fri, 1 Jun 2012 11:21:45 +0000 (12:21 +0100)]
Avoid early reuse of btree pages, causing incorrect query results.
When we allowed read-only transactions to skip assigning XIDs
we introduced the possibility that a fully deleted btree page
could be reused. This broke the index link sequence which could
then lead to indexscans silently returning fewer rows than would
have been correct. The actual incidence of silent errors from
this is thought to be very low because of the exact workload
required and locking pre-conditions. Fix is to remove pages only
if index page opaque->btpo.xact precedes RecentGlobalXmin.
Simon Riggs [Fri, 1 Jun 2012 07:19:06 +0000 (08:19 +0100)]
Provide interim statistics while in mid-checkpoint.
Re-implements similar functionality in 9.1 and previously which
was removed during split of checkpointer and bgwriter.
Tom Lane [Thu, 31 May 2012 03:47:57 +0000 (23:47 -0400)]
Force PL and range-type support functions to be owned by a superuser.
We allow non-superusers to create procedural languages (with restrictions)
and range datatypes. Previously, the automatically-created support
functions for these objects ended up owned by the creating user. This
represents a rather considerable security hazard, because the owning user
might be able to alter a support function's definition in such a way as to
crash the server, inject trojan-horse SQL code, or even execute arbitrary
C code directly. It appears that right now the only actually exploitable
problem is the infinite-recursion bug fixed in the previous patch for
CVE-2012-2655. However, it's not hard to imagine that future additions of
more ALTER FUNCTION capability might unintentionally open up new hazards.
To forestall future problems, cause these support functions to be owned by
the bootstrap superuser, not the user creating the parent object.
Tom Lane [Thu, 31 May 2012 03:27:57 +0000 (23:27 -0400)]
Ignore SECURITY DEFINER and SET attributes for a PL's call handler.
It's not very sensible to set such attributes on a handler function;
but if one were to do so, fmgr.c went into infinite recursion because
it would call fmgr_security_definer instead of the handler function proper.
There is no way for fmgr_security_definer to know that it ought to call the
handler and not the original function referenced by the FmgrInfo's fn_oid,
so it tries to do the latter, causing the whole process to start over
again.
Ordinarily such misconfiguration of a procedural language's handler could
be written off as superuser error. However, because we allow non-superuser
database owners to create procedural languages and the handler for such a
language becomes owned by the database owner, it is possible for a database
owner to crash the backend, which ideally shouldn't be possible without
superuser privileges. In 9.2 and up we will adjust things so that the
handler functions are always owned by superusers, but in existing branches
this is a minor security fix.
Problem noted by Noah Misch (after several of us had failed to detect
it :-(). This is CVE-2012-2655.
Tom Lane [Wed, 30 May 2012 23:58:35 +0000 (19:58 -0400)]
Expand the allowed range of timezone offsets to +/-15:59:59 from Greenwich.
We used to only allow offsets less than +/-13 hours, then it was +/14,
then it was +/-15. That's still not good enough though, as per today's bug
report from Patric Bechtel. This time I actually looked through the Olson
timezone database to find the largest offsets used anywhere. The winners
are Asia/Manila, at -15:56:00 until 1844, and America/Metlakatla, at
+15:13:42 until 1867. So we'd better allow offsets less than +/-16 hours.
Given the history, we are way overdue to have some greppable #define
symbols controlling this, so make some ... and also remove an obsolete
comment that didn't get fixed the last time.
Robert Haas [Wed, 30 May 2012 20:17:46 +0000 (16:17 -0400)]
Fix two more bugs in fast-path relation locking.
First, the previous code failed to account for the fact that, during Hot
Standby operation, the startup process takes AccessExclusiveLocks on
relations without setting MyDatabaseId. This resulted in fast path
strong lock counts failing to be incremented with the startup process
took locks, which in turn allowed conflicting lock requests to succeed
when they should not have. Report by Erik Rijkers, diagnosis by Heikki
Linnakangas.
Second, LockReleaseAll() failed to honor the allLocks and lockmethodid
restrictions with respect to fast-path locks. It's not clear to me
whether this produces any user-visible breakage at the moment, but it's
certainly wrong. Rearrange order of operations in LockReleaseAll to fix.
Noted by Tom Lane.
Tom Lane [Wed, 30 May 2012 14:53:30 +0000 (10:53 -0400)]
Fix incorrect password transformation in contrib/pgcrypto's DES crypt().
Overly tight coding caused the password transformation loop to stop
examining input once it had processed a byte equal to 0x80. Thus, if the
given password string contained such a byte (which is possible though not
highly likely in UTF8, and perhaps also in other non-ASCII encodings), all
subsequent characters would not contribute to the hash, making the password
much weaker than it appears on the surface.
This would only affect cases where applications used DES crypt() to encode
passwords before storing them in the database. If a weak password has been
created in this fashion, the hash will stop matching after this update has
been applied, so it will be easy to tell if any passwords were unexpectedly
weak. Changing to a different password would be a good idea in such a case.
(Since DES has been considered inadequately secure for some time, changing
to a different encryption algorithm can also be recommended.)
This code, and the bug, are shared with at least PHP, FreeBSD, and OpenBSD.
Since the other projects have already published their fixes, there is no
point in trying to keep this commit private.
This bug has been assigned CVE-2012-2143, and credit for its discovery goes
to Rubin Xu and Joseph Bonneau.