It's easy to forget using SYSTEMQUOTEs when constructing command strings
for system() or popen(). Even if we fix all the places missing it now, it is
bound to be forgotten again in the future. Introduce wrapper functions that
do the the extra quoting for you, and get rid of SYSTEMQUOTEs in all the
callers.
We previosly used SYSTEMQUOTEs in all the hard-coded command strings, and
this doesn't change the behavior of those. But user-supplied commands, like
archive_command, restore_command, COPY TO/FROM PROGRAM calls, as well as
pgbench's \shell, will now gain an extra pair of quotes. That is desirable,
but if you have existing scripts or config files that include an extra
pair of quotes, those might need to be adjusted.
Reviewed by Amit Kapila and Tom Lane
ruleutils.c tries to cope with additions/deletions/renamings of columns in
tables referenced by views, by means of adding machine-generated aliases to
the printed form of a view when needed to preserve the original semantics.
A recent blog post by Marko Tiikkaja pointed out a case I'd missed though:
if one input of a join with USING is itself a join, there is nothing to
stop the user from adding a column of the same name as the USING column to
whichever side of the sub-join didn't provide the USING column. And then
there'll be an error when the view is re-parsed, since now the sub-join
exposes two columns matching the USING specification. We were catching a
lot of related cases, but not this one, so add some logic to cope with it.
Back-patch to 9.3, which is the first release that makes any serious
attempt to cope with such cases (cf commit 2ffa740be and follow-ons).
If we have an array of records stored on disk, the individual record fields
cannot contain out-of-line TOAST pointers: the tuptoaster.c mechanisms are
only prepared to deal with TOAST pointers appearing in top-level fields of
a stored row. The same applies for ranges over composite types, nested
composites, etc. However, the existing code only took care of expanding
sub-field TOAST pointers for the case of nested composites, not for other
structured types containing composites. For example, given a command such
as
UPDATE tab SET arraycol = ARRAY[(ROW(x,42)::mycompositetype] ...
where x is a direct reference to a field of an on-disk tuple, if that field
is long enough to be toasted out-of-line then the TOAST pointer would be
inserted as-is into the array column. If the source record for x is later
deleted, the array field value would become a dangling pointer, leading
to errors along the line of "missing chunk number 0 for toast value ..."
when the value is referenced. A reproducible test case for this was
provided by Jan Pecek, but it seems likely that some of the "missing chunk
number" reports we've heard in the past were caused by similar issues.
Code-wise, the problem is that PG_DETOAST_DATUM() is not adequate to
produce a self-contained Datum value if the Datum is of composite type.
Seen in this light, the problem is not just confined to arrays and ranges,
but could also affect some other places where detoasting is done in that
way, for example form_index_tuple().
I tried teaching the array code to apply toast_flatten_tuple_attribute()
along with PG_DETOAST_DATUM() when the array element type is composite,
but this was messy and imposed extra cache lookup costs whether or not any
TOAST pointers were present, indeed sometimes when the array element type
isn't even composite (since sometimes it takes a typcache lookup to find
that out). The idea of extending that approach to all the places that
currently use PG_DETOAST_DATUM() wasn't attractive at all.
This patch instead solves the problem by decreeing that composite Datum
values must not contain any out-of-line TOAST pointers in the first place;
that is, we expand out-of-line fields at the point of constructing a
composite Datum, not at the point where we're about to insert it into a
larger tuple. This rule is applied only to true composite Datums, not
to tuples that are being passed around the system as tuples, so it's not
as invasive as it might sound at first. With this approach, the amount
of code that has to be touched for a full solution is greatly reduced,
and added cache lookup costs are avoided except when there actually is
a TOAST pointer that needs to be inlined.
The main drawback of this approach is that we might sometimes dereference
a TOAST pointer that will never actually be used by the query, imposing a
rather large cost that wasn't there before. On the other side of the coin,
if the field value is used multiple times then we'll come out ahead by
avoiding repeat detoastings. Experimentation suggests that common SQL
coding patterns are unaffected either way, though. Applications that are
very negatively affected could be advised to modify their code to not fetch
columns they won't be using.
In future, we might consider reverting this solution in favor of detoasting
only at the point where data is about to be stored to disk, using some
method that can drill down into multiple levels of nested structured types.
That will require defining new APIs for structured types, though, so it
doesn't seem feasible as a back-patchable fix.
Note that this patch changes HeapTupleGetDatum() from a macro to a function
call; this means that any third-party code using that macro will not get
protection against creating TOAST-pointer-containing Datums until it's
recompiled. The same applies to any uses of PG_RETURN_HEAPTUPLEHEADER().
It seems likely that this is not a big problem in practice: most of the
tuple-returning functions in core and contrib produce outputs that could
not possibly be toasted anyway, and the same probably holds for third-party
extensions.
This bug has existed since TOAST was invented, so back-patch to all
supported branches.
Be more clear about failure cases in relfilenode->relation lookup,
and fix some other places that were inconsistent or not per our
message style guidelines.
Andres Freund and Tom Lane
This was intended to work always, but the previous code only allowed
it if at least one message was successfully read by the receiver
before the sender detached the queue.
Report by Petr Jelinek. Patch by me.
Commit a730183926 created rather a mess by
putting dependencies on backend-only include files into include/common.
We really shouldn't do that. To clean it up:
* Move TABLESPACE_VERSION_DIRECTORY back to its longtime home in
catalog/catalog.h. We won't consider this symbol part of the FE/BE API.
* Push enum ForkNumber from relfilenode.h into relpath.h. We'll consider
relpath.h as the source of truth for fork numbers, since relpath.c was
already partially serving that function, and anyway relfilenode.h was
kind of a random place for that enum.
* So, relfilenode.h now includes relpath.h rather than vice-versa. This
direction of dependency is fine. (That allows most, but not quite all,
of the existing explicit #includes of relpath.h to go away again.)
* Push forkname_to_number from catalog.c to relpath.c, just to centralize
fork number stuff a bit better.
* Push GetDatabasePath from catalog.c to relpath.c; it was rather odd
that the previous commit didn't keep this together with relpath().
* To avoid needing relfilenode.h in common/, redefine the underlying
function (now called GetRelationPath) as taking separate OID arguments,
and make the APIs using RelFileNode or RelFileNodeBackend into macro
wrappers. (The macros have a potential multiple-eval risk, but none of
the existing call sites have an issue with that; one of them had such a
risk already anyway.)
* Fix failure to follow the directions when "init" fork type was added;
specifically, the errhint in forkname_to_number wasn't updated, and neither
was the SGML documentation for pg_relation_size().
* Fix tablespace-path-too-long check in CreateTableSpace() to account for
fork-name component of maximum-length pathnames. This requires putting
FORKNAMECHARS into a header file, but it was rather useless (and
actually unreferenced) where it was.
The last couple of items are potentially back-patchable bug fixes,
if anyone is sufficiently excited about them; but personally I'm not.
Per a gripe from Christoph Berg about how include/common wasn't
self-contained.
Since ruleutils.c recurses, it could be driven to stack overflow by
deeply nested constructs. Very large queries might also take long
enough to deparse that a check for interrupts seems like a good idea.
Stick appropriate tests into a couple of key places.
Noted by Greg Stark. Back-patch to all supported branches.
A query such as "SELECT x UNION SELECT y UNION SELECT z UNION ..."
produces a left-deep nested parse tree, which we formerly showed in its
full nested glory and with all the possible parentheses. This does little
for readability, though, and long UNION lists resulting in excessive
indentation are common. Instead, let's omit parentheses and indent all
the subqueries at the same level in such cases.
This patch skips indentation/parenthesization whenever the lefthand input
of a SetOperationStmt is another SetOperationStmt of the same kind and
ALL/DISTINCT property. We could teach the code the exact syntactic
precedence of set operations and thereby avoid parenthesization in some
more cases, but it's not clear that that'd be a readability win: it seems
better to parenthesize if the set operation changes. (As an example,
if there's one UNION in a long list of UNION ALL, it now stands out like
a sore thumb, which seems like a good thing.)
Back-patch to 9.3. This completes our response to a complaint from Greg
Stark that since commit 62e666400d there's a performance problem in pg_dump
for views containing long UNION sequences (or other types of deeply nested
constructs). The previous commit 0601cb54da
handles the general problem, but this one makes the specific case of UNION
lists look a lot nicer.
Continuing to indent no matter how deeply nested we get doesn't really
do anything for readability; what's worse, it results in O(N^2) total
whitespace, which can become a performance and memory-consumption issue.
To address this, once we get past 40 characters of indentation, reduce
the indentation step distance 4x, and also limit the maximum indentation
by reducing it modulo 40. This latter choice is a bit weird at first
glance, but it seems to preserve readability better than a simple cap
would do.
Back-patch to 9.3, because since commit 62e666400d the performance issue
is a hazard for pg_dump.
Greg Stark and Tom Lane
The code attempted to outdent JOIN clauses further left than the parent
FROM keyword, which was odd in any case, and led to inconsistent formatting
since in simple cases the clauses couldn't be moved any further left than
that. And it left a permanent decrement of the indentation level, causing
subsequent lines to be much further left than they should be (again, this
couldn't be seen in simple cases for lack of indentation to give up).
After a little experimentation I chose to make it indent JOIN keywords
two spaces from the parent FROM, which is one space more than the join's
lefthand input in cases where that appears on a different line from FROM.
Back-patch to 9.3. This is a purely cosmetic change, and the bug is quite
old, so that may seem arbitrary; but we are going to be making some other
changes to the indentation behavior in both HEAD and 9.3, so it seems
reasonable to include this in 9.3 too. I committed this one first because
its effects are more visible in the regression test results as they
currently stand than they will be later.
Some popen() calls were missing SYSTEMQUOTEs, which caused initdb and
pg_upgrade to fail on Windows, if the installation path contained both
spaces and @ signs.
Patch by Nikhil Deshpande. Backpatch to all supported versions.
The error test case in the plpython_do test resulted in a slightly
different error message with Python 3.4. So pick a different way to
test it that avoids that and is perhaps also a bit clearer.
In general we can't discard constant-NULL inputs, since they could change
the result of the AND/OR to be NULL. But at top level of WHERE, we do not
need to distinguish a NULL result from a FALSE result, so it's okay to
treat NULL as FALSE and then simplify AND/OR accordingly.
This is a very ancient oversight, but in 9.2 and later it can lead to
failure to optimize queries that previous releases did optimize, as a
result of more aggressive parameter substitution rules making it possible
to reduce more subexpressions to NULL constants. This is the root cause of
bug #10171 from Arnold Scheffler. We could alternatively have fixed that
by teaching orclauses.c to ignore constant-NULL OR arms, but it seems
better to get rid of them globally.
I resisted the temptation to back-patch this change into all active
branches, but it seems appropriate to back-patch as far as 9.2 so that
there will not be performance regressions of the kind shown in this bug.
feasible to display tables that have both many columns and some large
data in some columns (such as pg_stats).
Emre Hasegeli with review and rewriting from Sergey Muraviov and
reviewed by Greg Stark
In writeListPage, never take a full-page image of the page, because we
have all the information required to re-initialize in the WAL record
anyway. Before this fix, a full-page image was always generated, unless
full_page_writes=off, because when the page is initialized its LSN is
always 0. In stable-branches, keep the code to restore the backup blocks
if they exist, in case that the WAL is generated with an older minor
version, but in master Assert that there are no full-page images.
In the redo routine, add missing "off++". Otherwise the tuples are added
to the page in reverse order. That happens to be harmless because we
always scan and remove all the tuples together, but it was clearly wrong.
Also, it was masked by the first bug unless full_page_writes=off, because
the page was always restored from a full-page image.
Backpatch to all supported versions.
pg_controldata includes postgres.h not postgres_fe.h, so utils/palloc.h
must be able to compile in a "#define FRONTEND" context. It appears that
Solaris Studio is smart enough to persuade us to define PG_USE_INLINE,
but not smart enough to not make a copy of unreferenced static functions;
which leads to an unsatisfied reference to CurrentMemoryContext. So we
need an #ifndef FRONTEND around that declaration. Per buildfarm.
As noted some time ago, the original coding had a typo ("|" for "^")
that made the result less unique than intended. Even the intended
behavior is obsolete since it was based on wanting to produce a
usable value even if we didn't have int64 arithmetic --- a limitation
we stopped supporting years ago. Instead, let's redefine the system
identifier as tv_sec in the upper 32 bits (same as before), tv_usec
in the next 20 bits, and the low 12 bits of getpid() in the remaining
bits. This is still hardly guaranteed-universally-unique, but it's
noticeably better than before. Per my proposal at
<29019.1374535940@sss.pgh.pa.us>
This breaks the principle that common/ ought not depend on anything in the
server, not only code-wise but in the headers. The only arguable advantage
is avoidance of duplication of half a dozen extern declarations, and even
that is rather dubious, considering that the previous coding was wrong
about which declarations to duplicate: it exposed pnstrdup() to frontend
code even though no such function is provided in fe_memutils.c.
On the same principle, don't #include utils/memutils.h in the frontend
build of psprintf.c. This requires duplicating the definition of
MaxAllocSize, but that seems fine to me: there's no a-priori reason why
frontend code should use the same size limit as the backend anyway.
In passing, clean up some rather odd layout and ordering choices that
were imposed on palloc.h to reduce the number of #ifdefs required by
the previous approach.
Per gripe from Christoph Berg. There's still more work to do to make
include/common/ clean, but this part seems reasonably noncontroversial.
We should use exprTypmod() to extract the typmod of the expression,
instead of just blindly storing -1. This seems to have been an aboriginal
oversight in commit fc8d970cbc which
introduced general-expression indexes. The consequences are only cosmetic
at present, since the index machinery doesn't really look at typmod for
index columns; but still it seems best to describe the column type as
precisely as we can. Per off-list complaint from Thomas Fanghaenel.
Original coding failed to enlarge the array as required if
the requested tranche_id was equal to LWLockTranchesAllocated.
In passing, fix poor style of not casting the result of (re)palloc.
Commit 7d0f493f19 added infrastructure
to perform tests in assorted src/bin/ subdirectories, but forgot to
teach "make clean" to clean up the detritus the tests leave behind.
If a tuple is locked, and this lock is later upgraded either to an
update or to a stronger lock, and in the meantime some other process
tries to lock, update or delete the same tuple, it (the tuple) could end
up being updated twice, or having conflicting locks held.
The reason for this is that the second updater checks for a change in
Xmax value, or in the HEAP_XMAX_IS_MULTI infomask bit, after noticing
the first lock; and if there's a change, it restarts and re-evaluates
its ability to update the tuple. But it neglected to check for changes
in lock strength or in lock-vs-update status when those two properties
stayed the same. This would lead it to take the wrong decision and
continue with its own update, when in reality it shouldn't do so but
instead restart from the top.
This could lead to either an assertion failure much later (when a
multixact containing multiple updates is detected), or duplicate copies
of tuples.
To fix, make sure to compare the other relevant infomask bits alongside
the Xmax value and HEAP_XMAX_IS_MULTI bit, and restart from the top if
necessary.
Also, in the belt-and-suspenders spirit, add a check to
MultiXactCreateFromMembers that a multixact being created does not have
two or more members that are claimed to be updates. This should protect
against other bugs that might cause similar bogus situations.
Backpatch to 9.3, where the possibility of multixacts containing updates
was introduced. (In prior versions it was possible to have the tuple
lock upgraded from shared to exclusive, and an update would not restart
from the top; yet we're protected against a bug there because there's
always a sleep to wait for the locking transaction to complete before
continuing to do anything. Really, the fact that tuple locks always
conflicted with concurrent updates is what protected against bugs here.)
Per report from Andrew Dunstan and Josh Berkus in thread at
http://www.postgresql.org/message-id/534C8B33.9050807@pgexperts.com
Bug analysis by Andres Freund.
Once we've completed a PREPARE, our session is not running a transaction,
so its entry in pg_stat_activity should show xact_start as null, rather
than leaving the value as the start time of the now-prepared transaction.
I think possibly this oversight was triggered by faulty extrapolation
from the adjacent comment that says PrepareTransaction should not call
AtEOXact_PgStat, so tweak the wording of that comment.
Noted by Andres Freund while considering bug #10123 from Maxim Boguk,
although this error doesn't seem to explain that report.
Back-patch to all active branches.
pg_sequence_parameters() and pg_identify_object() have had incorrect
proallargtypes entries since 9.1 and 9.3 respectively. This was mostly
masked by the correct information in proargtypes, but a few operations
such as pg_get_function_arguments() (and thus psql's \df display) would
show the wrong data types for these functions' input parameters.
In HEAD, fix the wrong info, bump catversion, and add an opr_sanity
regression test to catch future mistakes of this sort.
In the back branches, just fix the wrong info so that installations
initdb'd with future minor releases will have the right data. We
can't force an initdb, and it doesn't seem like a good idea to add
a regression test that will fail on existing installations.
Andres Freund
Before 9.4, such an aggregate couldn't be declared, because its final
function would have to have polymorphic result type but no polymorphic
argument, which CREATE FUNCTION would quite properly reject. The
ordered-set-aggregate patch found a workaround: allow the final function
to be declared as accepting additional dummy arguments that have types
matching the aggregate's regular input arguments. However, we failed
to notice that this problem applies just as much to regular aggregates,
despite the fact that we had a built-in regular aggregate array_agg()
that was known to be undeclarable in SQL because its final function
had an illegal signature. So what we should have done, and what this
patch does, is to decouple the extra-dummy-arguments behavior from
ordered-set aggregates and make it generally available for all aggregate
declarations. We have to put this into 9.4 rather than waiting till
later because it slightly alters the rules for declaring ordered-set
aggregates.
The patch turned out a bit bigger than I'd hoped because it proved
necessary to record the extra-arguments option in a new pg_aggregate
column. I'd thought we could just look at the final function's pronargs
at runtime, but that didn't work well for variadic final functions.
It's probably just as well though, because it simplifies life for pg_dump
to record the option explicitly.
While at it, fix array_agg() to have a valid final-function signature,
and add an opr_sanity test to notice future deviations from polymorphic
consistency. I also marked the percentile_cont() aggregates as not
needing extra arguments, since they don't.
When marking a branch as half-dead, a pointer to the top of the branch is
stored in the leaf block's hi-key. During normal operation, the high key
was left in place, and the block number was just stored in the ctid field
of the high key tuple, but in WAL replay, the high key was recreated as a
truncated tuple with zero columns. For the sake of easier debugging, also
truncate the tuple in normal operation, so that the page is identical
after WAL replay. Also, rename the 'downlink' field in the WAL record to
'topparent', as that seems like a more descriptive name. And make sure
it's set to invalid when unlinking the leaf page.
Some ancient comments claimed that fn_nargs could be -1 to indicate a
variable number of input arguments; but this was never implemented, and
is at variance with what we ultimately did with "variadic" functions.
Update the comments.
Forgot to update LSN of left sibling's page, when creating a new root.
I fixed this for regular insertions and page splits earlier, but missed
new root creation.
The README incorrectly claimed that GIN posting tree pages contain an array
of uncompressed items in addition to compressed posting lists. Earlier
versions of the GIN posting list compression patch worked that way, but not
the one that was committed.
Don't use simple_heap_insert to insert the tuple to a sequence relation.
simple_heap_insert creates a heap insertion WAL record, and replaying that
will create a regular heap page without the special area containing the
sequence magic constant, which is wrong for a sequence. That was not a bug
because we always created a sequence WAL record after that, and replaying
that overwrote the bogus heap page, and the transient state could never be
seen by another backend because it was only done when creating a new
sequence relation. But it's simpler and cleaner to avoid that in the first
place.
Previously, these functions treated "" optin values as defaults in some
ways, but not in others, like when comparing to .pgpass. Also, add
documentation to clarify that now "" and NULL use defaults, like
PQsetdbLogin() has always done.
BACKWARD INCOMPATIBILITY
Patch by Adrian Vondendriesch, docs by me
Report by Jeff Janes
Because of gcc -Wmissing-prototypes, all functions in dynamically
loadable modules must have a separate prototype declaration. This is
meant to detect global functions that are not declared in header files,
but in cases where the function is called via dfmgr, this is redundant.
Besides filling up space with boilerplate, this is a frequent source of
compiler warnings in extension modules.
We can fix that by creating the function prototype as part of the
PG_FUNCTION_INFO_V1 macro, which such modules have to use anyway. That
makes the code of modules cleaner, because there is one less place where
the entry points have to be listed, and creates an additional check that
functions have the right prototype.
Remove now redundant prototypes from contrib and other modules.
Introduced in 585bca39: msgid is not used in the Windows code path.
Also adjust comments a tad (mostly to keep pgindent from messing it up).
David Rowley
If we set the all-visible flag after writing WAL record, and XLogInsert
takes a full-page image of the page, the image would not include the flag.
We will then proceed to set the VM bit, which would then be set without the
corresponding all-visible flag on the heap page.
Found by comparing page images on master and standby, after writing/replaying
each WAL record. (There is still a discrepancy: the all-visible flag won't
be set after replaying the HEAP_CLEAN record, even though it is set in the
master. However, it will be set when replaying the HEAP2_VISIBLE record and
setting the VM bit, so the all-visible flag and VM bit are always consistent
on the standby, even though they are momentarily out-of-sync with master)
Backpatch to 9.3 where this code was introduced.
Now that EXPLAIN also outputs a "planning time" measurement, the use of
"total" here seems rather confusing: it sounds like it might include the
planning time which of course it doesn't. Majority opinion was that
"execution time" is a better label, so we'll call it that.
This should be noted as a backwards incompatibility for tools that examine
EXPLAIN ANALYZE output.
In passing, I failed to resist the temptation to do a little editing on the
materialized-view example affected by this change.
Previously, 'int' was used for socket values in libpq, but socket values
are unsigned on Windows. This is a style correction.
Initial patch and previous PGINVALID_SOCKET initial patch by Joel
Jacobson, modified by me
Report from PVS-Studio
Previously it wasn't clear from --help that -F, -R, -z, -0 only
controlled psql unaligned output.
Initial patch from Jov <amutu@amutu.com>, adjustments by me
Now that we're pretty much feature-frozen, it's time to update the checks
on system catalog foreign-key references.
(It looks like we missed doing this altogether for 9.3. Sigh.)
This has probably been broken for quite a long time. Buildfarm member
currawong's current results suggest that it's been broken since 9.1, so
backpatch this to that branch.
This only supports Python 2 - I will handle Python 3 separately, but
this is a fairly simple fix.
According to the Single Unix Spec and assorted man pages, you're supposed
to use the constants named AF_xxx when setting ai_family for a getaddrinfo
call. In a few places we were using PF_xxx instead. Use of PF_xxx
appears to be an ancient BSD convention that was not adopted by later
standardization. On BSD and most later Unixen, it doesn't matter much
because those constants have equivalent values anyway; but nonetheless
this code is not per spec.
In the same vein, replace PF_INET by AF_INET in one socket() call, which
wasn't even consistent with the other socket() call in the same function
let alone the remainder of our code.
Per investigation of a Cygwin trouble report from Marco Atzeri. It's
probably a long shot that this will fix his issue, but it's wrong in
any case.
Bind attempts to an LDAP server should time out after two seconds,
allowing additional lines in the service control file to be parsed
(which provide a fall back to a secondary LDAP server or default options).
The existing code failed to enforce that timeout during TCP connect,
resulting in a hang far longer than two seconds if the LDAP server
does not respond.
Laurenz Albe
These are natural complements to the functions added by commit
0886fc6a5c, but they weren't included
in the original patch for some reason. Add them.
Patch by me, per a complaint by Tom Lane. Review by Tatsuo
Ishii.
Apparently, Windows can sometimes return an error code even when the
operation actually worked just fine. Rearrange the order of checks
according to what appear to be the best practices in this area.
Amit Kapila
Previously, in some places, socket creation errors were checked for
negative values, which is not true for Windows because sockets are
unsigned. This masked socket creation errors on Windows.
Backpatch through 9.0. 8.4 doesn't have the infrastructure to fix this.
I mixed up BLCKSZ and XLOG_BLCKSZ when I changed the way the buffer is
allocated a couple of weeks ago. With the default settings, they are both
8k, but they can be changed at compile-time.
In psql \d+, display oids only when they exist, and display replication
identity only when it is non-default. Also document the defaults for
replication identity for system and non-system tables. Update
regression output.
Add vacuumdb option --analyze-in-stages which runs ANALYZE three times
with different configuration settings, adopting the logic from the
analyze_new_cluster.sh script that pg_upgrade generates. That way,
users of pg_dump/pg_restore can also use that functionality.
Change pg_upgrade to create the script so that it calls vacuumdb instead
of implementing the logic itself.
By default, lcov will call whatever gcov it can find in the path. But
if the user has specified a different gcov to configure, this could be
incompatible. So tell lcov explicitly with an option which gcov program
to call.
This allows squeezing out the unused space in full-page writes. And more
importantly, it can be a useful debugging aid.
In hindsight we should've done this back when GIN was added - we wouldn't
need the 'maxoff' field in the page opaque struct if we had used pd_lower
and pd_upper like on normal pages. But as long as there can be pages in the
index that have been binary-upgraded from pre-9.4 versions, we can't rely
on that, and have to continue using 'maxoff'.
Most of the code churn comes from renaming some macros, now that they're
used on internal pages, too.
This change is completely backwards-compatible, no effect on pg_upgrade.
Make sure we throw an error instead of silently doing the wrong thing when
fed a strategy number we don't recognize. Also, in the places that did
already throw an error, spell the error message in a way more consistent
with our message style guidelines.
Per report from Paul Jones. Although this is a bug, it won't occur unless
a superuser tries to do something he shouldn't, so it doesn't seem worth
back-patching.
The entry B-tree pages all follow the standard page layout. The 9.3 code has
this right. I inadvertently changed this at some point during the big
refactorings in git master.
Repositioning the tuplestore seek pointer in window_gettupleslot() turns
out to be a very significant expense when the window frame is sizable and
the frame end can move. To fix, introduce a tuplestore function for
skipping an arbitrary number of tuples in one call, parallel to the one we
introduced for tuplesort objects in commit 8d65da1f. This reduces the cost
of window_gettupleslot() to O(1) if the tuplestore has not spilled to disk.
As in the previous commit, I didn't try to do any real optimization of
tuplestore_skiptuples for the case where the tuplestore has spilled to
disk. There is probably no practical way to get the cost to less than O(N)
anyway, but perhaps someone can think of something later.
Also fix PersistHoldablePortal() to make use of this API now that we have
it.
Based on a suggestion by Dean Rasheed, though this turns out not to look
much like his patch.
Given that ALTER TABLESPACE has moved on from just existing for
general purpose rename/owner changes, it deserves its own top-level
production in the grammar. This also cleans up the RenameStmt to
only ever be used for actual RENAMEs again- it really wasn't
appropriate to hide non-RENAME productions under there.
Noted by Alvaro.
Looks like we can end up with different plans happening on the
buildfarm, which breaks the regression tests when we include
EXPLAIN output (which is done in the regression tests for
updatable security views, to ensure that the user-defined
function isn't pushed down to a level where it could view the
rows before the security quals are applied).
This adds in ANALYZE to hopefully make the plans consistent.
The ANALYZE ends up changing the original plan too, so the
update looks bigger than it really is. The new plan looks
perfectly valid, of course.
Views which are marked as security_barrier must have their quals
applied before any user-defined quals are called, to prevent
user-defined functions from being able to see rows which the
security barrier view is intended to prevent them from seeing.
Remove the restriction on security barrier views being automatically
updatable by adding a new securityQuals list to the RTE structure
which keeps track of the quals from security barrier views at each
level, independently of the user-supplied quals. When RTEs are
later discovered which have securityQuals populated, they are turned
into subquery RTEs which are marked as security_barrier to prevent
any user-supplied quals being pushed down (modulo LEAKPROOF quals).
Dean Rasheed, reviewed by Craig Ringer, Simon Riggs, KaiGai Kohei
First installment of the promised moving-aggregate support in built-in
aggregates: count(), sum(), avg(), stddev() and variance() for
assorted datatypes, though not for float4/float8.
In passing, remove a 2001-vintage kluge in interval_accum(): interval
array elements have been properly aligned since around 2003, but
nobody remembered to take out this workaround. Also, fix a thinko
in the opr_sanity tests for moving-aggregate catalog entries.
David Rowley and Florian Pflug, reviewed by Dean Rasheed
Until now, when executing an aggregate function as a window function
within a window with moving frame start (that is, any frame start mode
except UNBOUNDED PRECEDING), we had to recalculate the aggregate from
scratch each time the frame head moved. This patch allows an aggregate
definition to include an alternate "moving aggregate" implementation
that includes an inverse transition function for removing rows from
the aggregate's running state. As long as this can be done successfully,
runtime is proportional to the total number of input rows, rather than
to the number of input rows times the average frame length.
This commit includes the core infrastructure, documentation, and regression
tests using user-defined aggregates. Follow-on commits will update some
of the built-in aggregates to use this feature.
David Rowley and Florian Pflug, reviewed by Dean Rasheed; additional
hacking by me
There were a couple of bugs here. First, if the fuzzy limit was exceeded,
the loop in entryGetItem might drop out too soon if a whole block needs to
be skipped because it's < advancePast ("continue" in a while-loop checks the
loop condition too). Secondly, the loop checked when stepping to a new page
that there is at least one offset on the page < advancePast, but we cannot
rely on that on subsequent calls of entryGetItem, because advancePast might
change in between. That caused the skipping loop to read bogus items in the
TbmIterateResult's offset array.
First item and fix by Alexander Korotkov, second bug pointed out by Fabrízio
de Royes Mello, by a small variation of Alexander's test query.
This operator class can accelerate subnet/supernet tests as well as
btree-equivalent ordered comparisons. It also handles a new network
operator inet && inet (overlaps, a/k/a "is supernet or subnet of"),
which is expected to be useful in exclusion constraints.
Ideally this opclass would be the default for GiST with inet/cidr data,
but we can't mark it that way until we figure out how to do a more or
less graceful transition from the current situation, in which the
really-completely-bogus inet/cidr opclasses in contrib/btree_gist are
marked as default. Having the opclass in core and not default is better
than not having it at all, though.
While at it, add new documentation sections to allow us to officially
document GiST/GIN/SP-GiST opclasses, something there was never a clear
place to do before. I filled these in with some simple tables listing
the existing opclasses and the operators they support, but there's
certainly scope to put more information there.
Emre Hasegeli, reviewed by Andreas Karlsson, further hacking by me
Instead of storing the ID of the dynamic shared memory control
segment in a file within the data directory, store it in the main
control segment. This avoids a number of nasty corner cases,
most seriously that doing an online backup and then using it on
the same machine (e.g. to fire up a standby) would result in the
standby clobbering all of the master's dynamic shared memory
segments.
Per complaints from Heikki Linnakangas, Fujii Masao, and Tom
Lane.
These functions won't throw an error if the object doesn't exist,
or if (for functions and operators) there's more than one matching
object.
Yugo Nagata and Nozomi Anzai, reviewed by Amit Khandekar, Marti
Raudsepp, Amit Kapila, and me.
Don't reset the rightlink of a page when replaying a page update record.
This was a leftover from pre-hot standby days, when it was not possible to
have scans concurrent with WAL replay. Resetting the right-link was not
necessary back then either, but it was done for the sake of tidiness. But
with hot standby, it's wrong, because a concurrent scan might still need it.
Backpatch all versions with hot standby, 9.0 and above.
The one existing assertion of this type has tripped a few times in the
buildfarm lately, but it's not clear whether the problem is really
originating there or whether it's leftovers from a trip through one
of the other two paths that lack a matching assertion. So add one.
Since the same bug(s) most likely exist(s) in the back-branches also,
back-patch to 9.2, where the fast-path lock mechanism was added.
This doesn't seem to be useful any more, and it's not really worth the
effort to keep updating it every time relevant dependencies or calling
signatures in the shared memory or semaphore code change.
Forgot to set the incomplete-split flag on the left page half, in redo of a
page split.
Spotted this by comparing the page contents on master and standby, after
inserting/applying each WAL record.
Infrastructure to allow
plpgsql.extra_warnings
plpgsql.extra_errors
Initial extra checks only for shadowed_variables
Marko Tiikkaja and Petr Jelinek
Reviewed by Simon Riggs and Pavel Stěhule
VALIDATE CONSTRAINT
CLUSTER ON
SET WITHOUT CLUSTER
ALTER COLUMN SET STATISTICS
ALTER COLUMN SET ()
ALTER COLUMN RESET ()
All other sub-commands use AccessExclusiveLock
Simon Riggs and Noah Misch
Reviews by Robert Haas and Andres Freund
Formerly, we set up the postmaster's signal handling only when we were
about to start launching subprocesses. This is a bad idea though, as
it means that for example a SIGINT arriving before that will kill the
postmaster instantly, perhaps leaving lockfiles, socket files, shared
memory, etc laying about. We'd rather that such a signal caused orderly
postmaster termination including releasing of those resources. A simple
fix is to move the PostmasterMain stanza that initializes signal handling
to an earlier point, before we've created any such resources. Then, an
early-arriving signal will be blocked until we're ready to deal with it
in the usual way. (The only part that really needs to be moved up is
blocking of signals, but it seems best to keep the signal handler
installation calls together with that; for one thing this ensures the
kernel won't drop any signals we wished to get. The handlers won't get
invoked in any case until we unblock signals in ServerLoop.)
Per a report from MauMau. He proposed changing the way "pg_ctl stop"
works to deal with this, but that'd just be masking one symptom not
fixing the core issue.
It's been like this since forever, so back-patch to all supported branches.
Also add a regression test for a GIN index with enough items with the same
key, so that a GIN posting tree gets created. Apparently none of the
existing GIN tests were large enough for that.
This code is new, no backpatching required.
EXEC_BACKEND builds (i.e., Windows) failed to absorb values of PGC_BACKEND
parameters if they'd been changed post-startup via the config file. This
for example prevented log_connections from working if it were turned on
post-startup. The mechanism for handling this case has always been a bit
of a kluge, and it wasn't revisited when we implemented EXEC_BACKEND.
While in a normal forking environment new backends will inherit the
postmaster's value of such settings, EXEC_BACKEND backends have to read
the settings from the CONFIG_EXEC_PARAMS file, and they were mistakenly
rejecting them. So this case has always been broken in the Windows port;
so back-patch to all supported branches.
Amit Kapila
Remarkably, this hasn't been noticed before, though it surely should
have been happening since around the fall of the Byzantine empire.
Commit 438b529604 changed path.c to depend on FRONTEND, and that exposed
the omission, per buildfarm reports.
I'm suspicious that some other subdirectories are missing this too,
but this one change is enough to make ecpg tests pass for me.
The code segment that removes the old symlink (if present) wasn't clued
into the fact that on Windows, symlinks are junction points which have
to be removed with rmdir().
Backpatch to 9.0, where the failing code was introduced.
MauMau, reviewed by Muhammad Asif Naeem and Amit Kapila
There's no really compelling reason to refuse to do these read-only,
non-server-starting options as root, and there's at least one good
reason to allow -C: pg_ctl uses -C to find out the true data directory
location when pointed at a config-only directory. On Windows, this is
done before dropping administrator privileges, which means that pg_ctl
fails for administrators if and only if a config-only layout is used.
Since the root-privilege check is done so early in startup, it's a bit
awkward to check for these switches. Make the somewhat arbitrary
decision that we'll only skip the root check if -C is the first switch.
This is not just to make the code a bit simpler: it also guarantees that
we can't misinterpret a --boot mode switch. (While AuxiliaryProcessMain
doesn't currently recognize any such switch, it might have one in the
future.) This is no particular problem for pg_ctl, and since the whole
behavior is undocumented anyhow, it's not a documentation issue either.
(--describe-config only works as the first switch anyway, so this is
no restriction for that case either.)
Back-patch to 9.2 where pg_ctl first began to use -C.
MauMau, heavily edited by me
This is needed because Windows services may get started with a different
current directory than where pg_ctl is executed. We want relative -D
paths to be interpreted relative to pg_ctl's CWD, similarly to what
happens on other platforms.
In support of this, move the backend's make_absolute_path() function
into src/port/path.c (where it probably should have been long since)
and get rid of the rather inferior version in pg_regress.
Kumar Rajeev Rastogi, reviewed by MauMau
The displayed sendtime and receipttime were always exactly equal, because
somebody forgot that timestamptz_to_str returns a static buffer (thereby
simplifying life for most callers, at the cost of complicating it for those
who need two results concurrently). Apply the same pstrdup solution used
by the other call sites with this issue. Back-patch to 9.2 where the
faulty code was introduced. Per bug #9849 from Haruka Takatsuka, though
this is not exactly his patch.
Possibly we should change timestamptz_to_str's API, but I wouldn't want
to do so in the back branches.
GetVirtualXIDsDelayingChkpt calls palloc, which isn't safe in a critical
section. I thought I covered this case with the exemption for the
checkpointer, but CreateCheckPoint is also called from the startup process.
For variadic functions (other than VARIADIC ANY), the syntaxes foo(x,y,...)
and foo(VARIADIC ARRAY[x,y,...]) should be considered equivalent, since the
former is converted to the latter at parse time. They have indeed been
equivalent, in all releases before 9.3. However, commit 75b39e790 made an
ill-considered decision to record which syntax had been used in FuncExpr
nodes, and then to make equal() test that in checking node equality ---
which caused the syntaxes to not be seen as equivalent by the planner.
This is the underlying cause of bug #9817 from Dmitry Ryabov.
It might seem that a quick fix would be to make equal() disregard
FuncExpr.funcvariadic, but the same commit made that untenable, because
the field actually *is* semantically significant for some VARIADIC ANY
functions. This patch instead adopts the approach of redefining
funcvariadic (and aggvariadic, in HEAD) as meaning that the last argument
is a variadic array, whether it got that way by parser intervention or was
supplied explicitly by the user. Therefore the value will always be true
for non-ANY variadic functions, restoring the principle of equivalence.
(However, the planner will continue to consider use of VARIADIC as a
meaningful difference for VARIADIC ANY functions, even though some such
functions might disregard it.)
In HEAD, this change lets us simplify the decompilation logic in
ruleutils.c, since the funcvariadic/aggvariadic flag tells directly whether
to print VARIADIC. However, in 9.3 we have to continue to cope with
existing stored rules/views that might contain the previous definition.
Fortunately, this just means no change in ruleutils.c, since its existing
behavior effectively ignores funcvariadic for all cases other than VARIADIC
ANY functions.
In HEAD, bump catversion to reflect the fact that FuncExpr.funcvariadic
changed meanings; this is sort of pro forma, since I don't believe any
built-in views are affected.
Unfortunately, this patch doesn't magically fix everything for affected
9.3 users. After installing 9.3.5, they might need to recreate their
rules/views/indexes containing variadic function calls in order to get
everything consistent with the new definition. As in the cited bug,
the symptom of a problem would be failure to use a nominally matching
index that has a variadic function call in its definition. We'll need
to mention this in the 9.3.5 release notes.
Memory allocation can fail if you run out of memory, and inside a critical
section that will lead to a PANIC. Use conservatively-sized arrays in stack
instead.
There was previously no explicit limit on the number of pages a GiST split
can produce, it was only limited by the number of LWLocks that can be held
simultaneously (100 at the moment). This patch adds an explicit limit of 75
pages. That should be plenty, a typical split shouldn't produce more than
2-3 page halves.
The bug has been there forever, but only backpatch down to 9.1. The code
was changed significantly in 9.1, and it doesn't seem worth the risk or
trouble to adapt this for 9.0 and 8.4.
The code for matching clients to pg_hba.conf lines that specify host names
(instead of IP address ranges) failed to complain if reverse DNS lookup
failed; instead it silently didn't match, so that you might end up getting
a surprising "no pg_hba.conf entry for ..." error, as seen in bug #9518
from Mike Blackwell. Since we don't want to make this a fatal error in
situations where pg_hba.conf contains a mixture of host names and IP
addresses (clients matching one of the numeric entries should not have to
have rDNS data), remember the lookup failure and mention it as DETAIL if
we get to "no pg_hba.conf entry". Apply the same approach to forward-DNS
lookup failures, too, rather than treating them as immediate hard errors.
Along the way, fix a couple of bugs that prevented us from detecting an
rDNS lookup error reliably, and make sure that we make only one rDNS lookup
attempt; formerly, if the lookup attempt failed, the code would try again
for each host name entry in pg_hba.conf. Since more or less the whole
point of this design is to ensure there's only one lookup attempt not one
per entry, the latter point represents a performance bug that seems
sufficient justification for back-patching.
Also, adjust src/port/getaddrinfo.c so that it plays as well as it can
with this code. Which is not all that well, since it does not have actual
support for rDNS lookup, but at least it should return the expected (and
required by spec) error codes so that the main code correctly perceives the
lack of functionality as a lookup failure. It's unlikely that PG is still
being used in production on any machines that require our getaddrinfo.c,
so I'm not excited about working harder than this.
To keep the code in the various branches similar, this includes
back-patching commits c424d0d105 and
1997f34db4 into 9.2 and earlier.
Back-patch to 9.1 where the facility for hostnames in pg_hba.conf was
introduced.
Initialization of this field was not being done according to the
st_changecount protocol (it has to be done within the changecount increment
range, not outside). And the test to see if the value should be reported
as null was wrong. Noted while perusing uses of Port.remote_hostname.
This was wrong from the introduction of this code (commit 4a25bc145),
so back-patch to 9.1.
Inserting a downlink to an internal page clears the incomplete-split flag
of the child's left sibling, so the left sibling's LSN also needs to be
updated and it needs to be marked dirty. The codepath for an insertion got
this right, but the case where the internal node is split because of
inserting the new downlink missed that.
Inserting a downlink to an internal page clears the incomplete-split flag
of the child's left sibling, so the left sibling's LSN also needs to be
updated.
Otherwise, the compiler might decide to move modifications to data
within this structure outside the enclosing SpinLockAcquire /
SpinLockRelease pair, leading to shared memory corruption.
This may or may not explain a recent lmgr-related buildfarm failure
on prairiedog, but it needs to be fixed either way.
Previously, such buffers weren't counted, with the possible result that
EXPLAIN (BUFFERS) and pg_stat_statements would understate the true
number of blocks dirtied by an SQL statement.
Back-patch to 9.2, where this counter was introduced.
Amit Kapila
Inserting (in retail) into the new 9.4 format GIN posting tree created much
larger WAL records than in 9.3. The previous strategy to WAL logging was
basically to log the whole page on each change, with the exception of
completely unmodified segments up to the first modified one. That was not
too bad when appending to the end of the page, as only the last segment had
to be WAL-logged, but per Fujii Masao's testing, even that produced 2x the
WAL volume that 9.3 did.
The new strategy is to keep track of changes to the posting lists in a more
fine-grained fashion, and also make the repacking" code smarter to avoid
decoding and re-encoding segments unnecessarily.
It is possible for a view or materialized view to depend on a table's
primary key, if the view query relies on functional dependency to
abbreviate a GROUP BY list. This is problematic for pg_dump since we
ordinarily want to dump view definitions in the pre-data section but
indexes in post-data. pg_dump knows how to deal with this situation for
regular views, by breaking the view's ON SELECT rule apart from the view
proper. But it had not been taught what to do about materialized views,
and in fact mistakenly dumped them as regular views in such cases, as
seen in bug #9616 from Jesse Denardo.
If we had CREATE OR REPLACE MATERIALIZED VIEW, we could fix this in a
manner analogous to what's done for regular views; but we don't yet,
and we'd not back-patch such a thing into 9.3 anyway. As a hopefully-
temporary workaround, break the circularity by postponing the matview
into post-data altogether when this case occurs.
Any OS user able to access the socket can connect as the bootstrap
superuser and in turn execute arbitrary code as the OS user running the
test. Protect against that by placing the socket in the temporary data
directory, which has mode 0700 thanks to initdb. Back-patch to 8.4 (all
supported versions). The hazard remains wherever the temporary cluster
accepts TCP connections, notably on Windows.
Attempts to run "make check" from a directory with a long name will now
fail. An alternative not sharing that problem was to place the socket
in a subdirectory of /tmp, but that is only secure if /tmp is sticky.
The PG_REGRESS_SOCK_DIR environment variable is available as a
workaround when testing from long directory paths.
As a convenient side effect, this lets testing proceed smoothly in
builds that override DEFAULT_PGSOCKET_DIR. Popular non-default values
like /var/run/postgresql are often unwritable to the build user.
Security: CVE-2014-0067
The original coding of EquivalenceClasses didn't foresee that appendrel
child relations might themselves be appendrels; but this is possible for
example when a UNION ALL subquery scans a table with inheritance children.
The oversight led to failure to optimize ordering-related issues very well
for the grandchild tables. After some false starts involving explicitly
flattening the appendrel representation, we found that this could be fixed
easily by removing a few implicit assumptions about appendrel parent rels
not being children themselves.
Kyotaro Horiguchi and Tom Lane, reviewed by Noah Misch
Commit 613c6d26bd sloppily replaced a
lookup of the UID obtained from getpeereid() with a lookup of the
server's own user name, thus totally destroying peer authentication.
Revert. Per report from Christoph Berg.
In passing, make sure get_user_name() zeroes *errstr on success on
Windows as well as non-Windows. I don't think any callers actually
depend on this ATM, but we should be consistent across platforms.
We must increment the refcount on "plntup" as soon as we have the
reference, not sometime later. Otherwise, if an error is thrown in
between, the Py_XDECREF(plntup) call in the PG_CATCH block removes a
refcount we didn't add, allowing the object to be freed even though
it's still part of the plpython function's parsetree.
This appears to be the cause of crashes seen on buildfarm member
prairiedog. It's a bit surprising that we've not seen it fail repeatably
before, considering that the regression tests have been exercising the
faulty code path since 2009.
The real-world impact is probably minimal, since it's unlikely anyone would
be provoking the "TD["new"] is not a dictionary" error in production, and
that's the only case that is actually wrong. Still, it's a bug affecting
the regression tests, so patch all supported branches.
In passing, remove dead variable "plstr", and demote "platt" to a local
variable inside the PG_TRY block, since we don't need to clean it up
in the PG_CATCH path.
If you compile with WAL_DEBUG and enable it with wal_debug=on, we used to
only pass the first XLogRecData entry to the rm_desc routine. I think the
original assumprion was that the first XLogRecData entry contains all the
necessary information for the rm_desc routine, but that's a pretty shaky
assumption. At least standby_redo didn't get the memo.
To fix, piece together all the data in a temporary buffer, and pass that to
the rm_desc routine.
It's been like this forever, but the patch didn't apply cleanly to
back-branches. Probably wouldn't be hard to fix the conflicts, but it's
not worth the trouble.
Display "replica identity" only for \d plus mode, exclude system schema
objects, and display all possible values, not just non-default,
non-index ones.
Set function parameter names and defaults. Add jsonb versions (which the
code already provided for so the actual new code is trivial). Add jsonb
regression tests and docs.
Bump catalog version (which I apparently forgot to do when jsonb was
committed).
Assert errors were thrown for functions being passed invalid encodings,
while the main code handled it just fine.
Also document that libpq's PQclientEncoding() returns -1 for an encoding
lookup failure.
Per report from Peter Geoghegan
The new format accepts exactly the same data as the json type. However, it is
stored in a format that does not require reparsing the orgiginal text in order
to process it, making it much more suitable for indexing and other operations.
Insignificant whitespace is discarded, and the order of object keys is not
preserved. Neither are duplicate object keys kept - the later value for a given
key is the only one stored.
The new type has all the functions and operators that the json type has,
with the exception of the json generation functions (to_json, json_agg etc.)
and with identical semantics. In addition, there are operator classes for
hash and btree indexing, and two classes for GIN indexing, that have no
equivalent in the json type.
This feature grew out of previous work by Oleg Bartunov and Teodor Sigaev, which
was intended to provide similar facilities to a nested hstore type, but which
in the end proved to have some significant compatibility issues.
Authors: Oleg Bartunov, Teodor Sigaev, Peter Geoghegan and Andrew Dunstan.
Review: Andres Freund
This covers all the SQL-standard trigger types supported for regular
tables; it does not cover constraint triggers. The approach for
acquiring the old row mirrors that for view INSTEAD OF triggers. For
AFTER ROW triggers, we spool the foreign tuples to a tuplestore.
This changes the FDW API contract; when deciding which columns to
populate in the slot returned from data modification callbacks, writable
FDWs will need to check for AFTER ROW triggers in addition to checking
for a RETURNING clause.
In support of the feature addition, refactor the TriggerFlags bits and
the assembly of old tuples in ModifyTable.
Ronan Dunklau, reviewed by KaiGai Kohei; some additional hacking by me.
equalTupleDescs() neglected both of these ConstrCheck fields, and
CreateTupleDescCopyConstr() neglected ccnoinherit. At this time, the
only known behavior defect resulting from these omissions is constraint
exclusion disregarding a CHECK constraint validated by an ALTER TABLE
VALIDATE CONSTRAINT statement issued earlier in the same transaction.
Back-patch to 9.2, where these fields were introduced.
Also fix the name of the dtrace probe for LWLockAcquireOrWait(). The
function was renamed from LWLockWaitUntilFree to LWLockAqcuireOrWait, but
the dtrace probe was neglected.
Pointed out by Andres Freund and the buildfarm.
Clear errno before calling readdir() and handle old MinGW errno bug
while adding full test coverage for readdir/closedir failures.
Backpatch through 8.4.
The special feature the XLogInsert slots had over regular LWLocks is the
insertingAt value that was updated atomically with releasing backends
waiting on it. Add new functions to the LWLock API to do that, and replace
the slots with LWLocks. This reduces the amount of duplicated code.
(There's still some duplication, but at least it's all in lwlock.c now.)
Reviewed by Andres Freund.
The previous method was overly complex and underly correct; in particular,
by assigning the default value with PGC_S_OVERRIDE, it prevented later
attempts to change the setting in postgresql.conf, as noted by Jeff Janes.
We should just assign the default value with source PGC_S_DYNAMIC_DEFAULT,
which will have the desired priority relative to the boot_val as well as
user-set values.
There is still a gap in this method: if there's an explicit assignment of
effective_cache_size = -1 in the postgresql.conf file, and that assignment
appears before shared_buffers is assigned, the code will substitute 4 times
the bootstrap default for shared_buffers, and that value will then persist
(since it will have source PGC_S_FILE). I don't see any very nice way
to avoid that though, and it's not a case to be expected in practice.
The existing comments in guc-file.l look forward to a redesign of the
DYNAMIC_DEFAULT mechanism; if that ever happens, we should consider this
case as one of the things we'd like to improve.
With this in place, a session blocking behind another one because of
tuple locks will get a context line mentioning the relation name, tuple
TID, and operation being done on tuple. For example:
LOG: process 11367 still waiting for ShareLock on transaction 717 after 1000.108 ms
DETAIL: Process holding the lock: 11366. Wait queue: 11367.
CONTEXT: while updating tuple (0,2) in relation "foo"
STATEMENT: UPDATE foo SET value = 3;
Most usefully, the new line is displayed by log entries due to
log_lock_waits, although of course it will be printed by any other log
message as well.
Author: Christian Kruse, some tweaks by Álvaro Herrera
Reviewed-by: Amit Kapila, Andres Freund, Tom Lane, Robert Haas
For a regex containing backrefs, pg_regexec() might fail to free all the
sub-DFAs that were created during execution, resulting in a permanent
(session lifespan) memory leak. Problem was introduced by me in commit
587359479a. Per report from Sandro Santilli;
diagnosis by Greg Stark.
It is no longer used, none of the resource managers have multi-record
actions that would make it unsafe to perform a restartpoint.
Also don't allow rm_cleanup to write WAL records, it's also no longer
required. Move the call to rm_cleanup routines to make it more symmetric
with rm_startup.
Splitting a page consists of two separate steps: splitting the child page,
and inserting the downlink for the new right page to the parent. Previously,
we handled the case that you crash in between those steps with a cleanup
routine after the WAL recovery had finished, which finished the incomplete
split. However, that doesn't help if the page split is interrupted but the
database doesn't crash, so that you don't perform WAL recovery. That could
happen for example if you run out of disk space.
Remove the end-of-recovery cleanup step. Instead, when a page is split, the
left page is marked with a new INCOMPLETE_SPLIT flag, and when the downlink
is inserted to the parent, the flag is cleared again. If an insertion sees
a page with the flag set, it knows that the split was interrupted for some
reason, and inserts the missing downlink before proceeding.
I used the same approach to fix GIN and GiST split algorithms earlier. This
was the last WAL cleanup routine, so we could get rid of that whole
machinery now, but I'll leave that for a separate patch.
Reviewed by Peter Geoghegan.
One path through the loop over indexes forgot to do index_close(). Rather
than adding a fourth call, restructure slightly so that there's only one.
In passing, get rid of an unnecessary syscache lookup: the pg_index struct
for the index is already available from its relcache entry.
Per report from YAMAMOTO Takashi, though this is a bit different from his
suggested patch. This is new code in HEAD, so no need for back-patch.
Revise the original decision to expose a uint64-based interface and
use Size everywhere possible. Avoid assuming that MAXIMUM_ALIGNOF is
8, or making any assumption about the relationship between that value
and sizeof(Size). If MAXIMUM_ALIGNOF is bigger, we'll now insert
padding after the length word; if it's smaller, we are now prepared
to read and write the length word in chunks.
Per discussion with Tom Lane.
The new function dsm_detach_all() can be used either by postmaster
children that don't wish to take any risk of accidentally corrupting
shared memory; or by forked children of regular backends with
the same need. This patch also updates the postmaster children that
already do PGSharedMemoryDetach() to do dsm_detach_all() as well.
Per discussion with Tom Lane.
The recently-fixed bug in WAL replay could result in not finding a parent
tuple for a heap-only tuple. The existing code would either Assert or
generate an invalid index entry, neither of which is desirable. Throw a
regular error instead.
On clean shutdown, walsender waits for all WAL to be replicated to a standby,
and exits. It determined whether that replication had been completed by
checking whether its sent location had been equal to a standby's flush
location. Unfortunately this condition never becomes true when the standby
such as pg_receivexlog which always returns an invalid flush location is
connecting to walsender, and then walsender waits forever.
This commit changes walsender so that it just checks a standby's write
location if a flush location is invalid.
Back-patch to 9.1 where enough infrastructure for this exists.
"8" was correct back when "disable" was the longest allowed value, but
since "verify-full" was added, it should be "12". Given the lack of
complaints, I wouldn't be surprised if nobody is actually using these
values ... but still, if they're in the API, they should be right.
Noticed while pursuing a different problem. It's been wrong for quite
a long time, so back-patch to all supported branches.
krb_srvname is actually not available anymore as a parameter server-side, since
with gssapi we accept all principals in our keytab. It's still used in libpq for
client side specification.
In passing remove declaration of krb_server_hostname, where all the functionality
was already removed.
Noted by Stephen Frost, though a different solution than his suggestion
In short, we don't allow a page to be deleted if it's the rightmost child
of its parent, but that situation can change after we check for it.
Problem
-------
We check that the page to be deleted is not the rightmost child of its
parent, and then lock its left sibling, the page itself, its right sibling,
and the parent, in that order. However, if the parent page is split after
the check but before acquiring the locks, the target page might become the
rightmost child, if the split happens at the right place. That leads to an
error in vacuum (I reproduced this by setting a breakpoint in debugger):
ERROR: failed to delete rightmost child 41 of block 3 in index "foo_pkey"
We currently re-check that the page is still the rightmost child, and throw
the above error if it's not. We could easily just give up rather than throw
an error, but that approach doesn't scale to half-dead pages. To recap,
although we don't normally allow deleting the rightmost child, if the page
is the *only* child of its parent, we delete the child page and mark the
parent page as half-dead in one atomic operation. But before we do that, we
check that the parent can later be deleted, by checking that it in turn is
not the rightmost child of the grandparent (potentially recursing all the
way up to the root). But the same situation can arise there - the
grandparent can be split while we're not holding the locks. We end up with
a half-dead page that we cannot delete.
To make things worse, the keyspace of the deleted page has already been
transferred to its right sibling. As the README points out, the keyspace at
the grandparent level is "out-of-whack" until the half-dead page is deleted,
and if enough tuples with keys in the transferred keyspace are inserted, the
page might get split and a downlink might be inserted into the grandparent
that is out-of-order. That might not cause any serious problem if it's
transient (as the README ponders), but is surely bad if it stays that way.
Solution
--------
This patch changes the page deletion algorithm to avoid that problem. After
checking that the topmost page in the chain of to-be-deleted pages is not
the rightmost child of its parent, and then deleting the pages from bottom
up, unlink the pages from top to bottom. This way, the intermediate stages
are similar to the intermediate stages in page splitting, and there is no
transient stage where the keyspace is "out-of-whack". The topmost page in
the to-be-deleted chain doesn't have a downlink pointing to it, like a page
split before the downlink has been inserted.
This also allows us to get rid of the cleanup step after WAL recovery, if we
crash during page deletion. The deletion will be continued at next VACUUM,
but the tree is consistent for searches and insertions at every step.
This bug is old, all supported versions are affected, but this patch is too
big to back-patch (and changes the WAL record formats of related records).
We have not heard any reports of the bug from users, so clearly it's not
easy to bump into. Maybe backpatch later, after this has had some field
testing.
Reviewed by Kevin Grittner and Peter Geoghegan.
This should eliminate the risk of recursive entry to syslog(3), which
appears to be the cause of the hang reported in bug #9551 from James
Morton.
Arguably, the real problem here is auth.c's willingness to turn on
ImmediateInterruptOK while executing fairly wide swaths of backend code.
We may well need to work at narrowing the code ranges in which the
authentication_timeout interrupt is enabled. For the moment, though,
this is a cheap and reasonably noninvasive fix for a field-reported
failure; the other approach would be complex and not necessarily
bug-free itself.
Back-patch to all supported branches.
Previously, psql would print the "COPY nnn" command status only for COPY
commands executed server-side. Now it will print that for frontend copies
too (including \copy). However, we continue to suppress the command status
for COPY TO STDOUT, since in that case the copy data has been routed to the
same place that the command status would go, and there is a risk of the
status line being mistaken for another line of COPY data. Doing that would
break existing scripts, and it doesn't seem worth the benefit --- this case
seems fairly analogous to SELECT, for which we also suppress the command
status.
Kumar Rajeev Rastogi, with substantial review by Amit Khandekar
Use TransactionIdIsInProgress, then TransactionIdDidCommit, to distinguish
whether a NOTIFY message's originating transaction is in progress,
committed, or aborted. The previous coding could accept a message from a
transaction that was still in-progress according to the PGPROC array;
if the client were fast enough at starting a new transaction, it might fail
to see table rows added/updated by the message-sending transaction. Which
of course would usually be the point of receiving the message. We noted
this type of race condition long ago in tqual.c, but async.c overlooked it.
The race condition probably cannot occur unless there are multiple NOTIFY
senders in action, since an individual backend doesn't send NOTIFY signals
until well after it's done committing. But if two senders commit in close
succession, it's certainly possible that we could see the second sender's
message within the race condition window while responding to the signal
from the first one.
Per bug #9557 from Marko Tiikkaja. This patch is slightly more invasive
than what he proposed, since it removes the now-redundant
TransactionIdDidAbort call.
Back-patch to 9.0, where the current NOTIFY implementation was introduced.
When a row is updated, and the new tuple version is put on the same page as
the old one, only WAL-log the part of the new tuple that's not identical to
the old. This saves significantly on the amount of WAL that needs to be
written, in the common case that most fields are not modified.
Amit Kapila, with a lot of back and forth with me, Robert Haas, and others.
With the GIN "fast scan" feature, GIN can skip items without fetching all
the keys for them, if it can prove that they don't match regardless of
those keys. So far, it has done the proving by calling the boolean
consistent function with all combinations of TRUE/FALSE for the unfetched
keys, but since that's O(n^2), it becomes unfeasible with more than a few
keys. We can avoid calling consistent with all the combinations, if we can
tell the operator class implementation directly which keys are unknown.
This commit includes a triConsistent function for the built-in array and
tsvector opclasses.
Alexander Korotkov, with some changes by me.
We don't take a full-page image of the GIN metapage; instead, the WAL record
contains all the information required to reconstruct it from scratch. But
to avoid torn page hazards, we must re-initialize it from the WAL record
every time, even if it already has a greater LSN, similar to how normal full
page images are restored.
This was highly unlikely to cause any problems in practice, because the GIN
metapage is small. We rely on an update smaller than a 512 byte disk sector
to be atomic elsewhere, at least in pg_control. But better safe than sorry,
and this would be easy to overlook if more fields are added to the metapage
so that it's no longer small.
Reported by Noah Misch. Backpatch to all supported versions.
Commit 08146775ac changed do_copy() to
temporarily scribble on pset.cur_cmd_source. That was a mighty ugly bit of
code in any case, but in particular it broke handleCopyIn's ability to tell
whether it was reading from the current script source file (in which case
pset.lineno should be incremented for each line of COPY data), or from
someplace else (in which case it shouldn't). The former case still worked,
the latter not so much. The visible effect was that line numbers reported
for errors in a script file would be wrong if there were an earlier \copy
that was reading anything other than inline-in-the-script-file data.
To fix, introduce another pset field that holds the file do_copy wants the
COPY code to use. This is a little bit ugly, but less so than passing the
file down explicitly through several layers that aren't COPY-specific.
Extracted from a larger patch by Kumar Rajeev Rastogi; that patch also
changes printing of COPY command tags, which is not a bug fix and shouldn't
get back-patched. This particular idea was from a suggestion by Amit
Khandekar, if I'm reading the thread correctly.
Back-patch to 9.2 where the faulty code was introduced.
In order for this to work, walsenders need the optional ability to
connect to a database, so the "replication" keyword now allows true
or false, for backward-compatibility, and the new value "database"
(which causes the "dbname" parameter to be respected).
walsender needs to loop not only when idle but also when sending
decoded data to the user and when waiting for more xlog data to decode.
This means that there are now three separate loops inside walsender.c;
although some refactoring has been done here, this is still a bit ugly.
Andres Freund, with contributions from Álvaro Herrera, and further
review by me.
If a postmaster child invokes fork() and then calls on_exit_reset, that
should be sufficient to let it exit() without breaking anything, but
dynamic shared memory broke that by not updating on_exit_reset() to
discard callbacks registered with dynamic shared memory segments.
Per investigation of a complaint from Tom Lane.
Return '4' and report a meaningful error message when a non-existent or
invalid data directory is passed. Previously, pg_ctl would just report
the server was not running.
Patch by me and Amit Kapila
Report from Peter Eisentraut
In b89e151054 I had assumed it was ok to use anonymous unions as
struct members, but while a longstanding extension in many compilers,
it's only been standardized in C11.
To fix, remove one of the anonymous unions which tried to hide some
implementation specific enum values and give the other a name. The
latter unfortunately requires changes in output plugins, but since the
feature has only been added a few days ago...
Andres Freund
A fake relcache entry can "own" a SmgrRelation object, like a regular
relcache entry. But when it was free'd, the owner field in SmgrRelation
was not cleared, so it was left pointing to free'd memory.
Amazingly this apparently hasn't caused crashes in practice, or we would've
heard about it earlier. Andres found this with Valgrind.
Report and fix by Andres Freund, with minor modifications by me. Backpatch
to all supported versions.
In make_ruledef and get_query_def, we have long used AcquireRewriteLocks
to ensure that the querytree we are about to deparse is up-to-date and
the schemas of the underlying relations aren't changing. Howwever, that
function thinks the query is about to be executed, so it acquires locks
that are stronger than necessary for the purpose of deparsing. Thus for
example, if pg_dump asks to deparse a rule that includes "INSERT INTO t",
we'd acquire RowExclusiveLock on t. That results in interference with
concurrent transactions that might for example ask for ShareLock on t.
Since pg_dump is documented as being purely read-only, this is unexpected.
(Worse, it used to actually be read-only; this behavior dates back only
to 8.1, cf commit ba4200246.)
Fix this by adding a parameter to AcquireRewriteLocks to tell it whether
we want the "real" execution locks or only AccessShareLock.
Report, diagnosis, and patch by Dean Rasheed. Back-patch to all supported
branches.
Per the C standard, the routine should be passed an int, with a value that's
representable as an unsigned char or EOF. Passing a signed char is wrong,
because a negative value is not representable as an unsigned char.
Unfortunately no compiler warns about that.
If walsender doesn't hear from the client for the time specified by
wal_sender_timeout, it will conclude the connection or client is dead, and
disconnect. When half of wal_sender_timeout has elapsed, it sends a ping
to the client, leaving it the remainig half of wal_sender_timeout to
respond. However, it only checked if half of wal_sender_timeout had elapsed
when it was about to sleep, so if it was busy sending WAL to the client for
long enough, it would not send the ping request in time. Then the client
would not know it needs to send a reply, and the walsender will disconnect
even though the client is still alive. Fix that.
Andres Freund, reviewed by Robert Haas, and some further changes by me.
Backpatch to 9.3. Earlier versions relied on the client to send the
keepalives on its own, and hence didn't have this problem.
We should allow this so that matviews can be referenced in UPDATE/DELETE
statements in READ COMMITTED isolation level. The requirement for that
is that a re-fetch by TID will see the same row version the query saw
earlier, which is true of matviews, so there's no reason for the
restriction. Per bug #9398.
Michael Paquier, after a suggestion by me
Explicitly reject infinity/NaN inputs, rather than just assuming that
something else will do it for us. Per buildfarm.
While at it, make some over-parenthesized and under-legible code
more readable.
This was already documented a few lines further down, but the comment
just beside the field declaration could be misleading. Per gripe
from Kyotaro Horiguchi.
We were unlinking the permanent file, not the non-permanent one. But
since the stat collector already unlinks all permanent files on startup,
there was nothing for it to unlink. The non-permanent file remained in
place, and was copied to the permanent directory on shutdown, so in
effect no file was ever dropped.
Backpatch to 9.3, where the issue was introduced by commit 187492b6c2.
Before that, there were no per-database files and thus no file to drop
on DROP DATABASE.
Per report from Thom Brown.
Author: Tomáš Vondra
Instead of having read_post_opts() depend on the memory allocated for
the config file (which is now getting free'd), pg_strdup() for
post_opts and exec_path (similar to how it's being done elsewhere).
Noted by Thom Brown.
CheckRequiredParameterValues() should perform the checks if archive recovery
was requested, even if we are going to perform crash recovery first.
Reported by Kyotaro HORIGUCHI. Backpatch to 9.2, like the crash-then-archive
recovery mode.
When entering crash recovery followed by archive recovery, and the latest
checkpoint is a shutdown checkpoint, and there are no more WAL records to
replay before transitioning from crash to archive recovery, we would not
immediately allow read-only connections in hot standby mode even if we
could. That's because when starting from a shutdown checkpoint, we set
lastReplayedEndRecPtr incorrectly to the record before the checkpoint
record, instead of the checkpoint record itself. We don't run the redo
routine of the shutdown checkpoint record, but starting recovery from it
goes through the same motions, so it should be considered as replayed.
Reported by Kyotaro HORIGUCHI. All versions with hot standby are affected,
so backpatch to 9.0.
The new, small, free_readfile managed to have bug in it which could
cause it to try and free something it shouldn't, and fix the case
where it was being called with an invalid pointer leading to a
segfault.
Noted by Bruce, issues introduced and fixed by me.
This forces an input field containing the quoted null string to be
returned as a NULL. Without this option, only unquoted null strings
behave this way. This helps where some CSV producers insist on quoting
every field, whether or not it is needed. The option takes a list of
fields, and only applies to those columns. There is an equivalent
column-level option added to file_fdw.
Ian Barwick, with some tweaking by Andrew Dunstan, reviewed by Payal
Singh.
Author: Pavel Stěhule, editorialized somewhat by Álvaro Herrera
Reviewed-by: Tomáš Vondra, Marko Tiikkaja
With input from Fabrízio de Royes Mello, Jim Nasby
pg_class is a special case for CLUSTER and VACUUM FULL, so although
commit 3cff1879f8 caused these
operations to advance relfrozenxid and relminmxid for all other
tables, it did not provide the same benefit for pg_class. This
plugs that gap.
Andres Freund
I changed the loop in 9.3 to use "goto send_failure" instead of "break" on
errors, but I missed this one case. It was a relatively harmless bug: if
the flush fails once it will most likely fail again as soon as we try to
flush the output again. But it's a bug nevertheless.
Report and fix by Andres Freund.
This feature, building on previous commits, allows the write-ahead log
stream to be decoded into a series of logical changes; that is,
inserts, updates, and deletes and the transactions which contain them.
It is capable of handling decoding even across changes to the schema
of the effected tables. The output format is controlled by a
so-called "output plugin"; an example is included. To make use of
this in a real replication system, the output plugin will need to be
modified to produce output in the format appropriate to that system,
and to perform filtering.
Currently, information can be extracted from the logical decoding
system only via SQL; future commits will add the ability to stream
changes via walsender.
Andres Freund, with review and other contributions from many other
people, including Álvaro Herrera, Abhijit Menon-Sen, Peter Gheogegan,
Kevin Grittner, Robert Haas, Heikki Linnakangas, Fujii Masao, Abhijit
Menon-Sen, Michael Paquier, Simon Riggs, Craig Ringer, and Steve
Singer.
This option makes pg_dump, pg_dumpall and pg_restore inject an IF EXISTS
clause to each DROP command they emit. (In pg_dumpall, the clause is
not added to individual objects drops, but rather to the CREATE DATABASE
commands, as well as CREATE ROLE and CREATE TABLESPACE.)
This allows for a better user dump experience when using --clean in case
some objects do not already exist. Per bug #7873 by Dave Rolsky.
Author: Pavel Stěhule
Reviewed-by: Jeevan Chalke, Álvaro Herrera, Josh Kupershmidt
Because of the new SLOT clause in the START_REPLICATION command, it's
possible for the command to end up too long for the old maximum buffer
length.
Andres Freund
Additional non-security issues/improvements spotted by Coverity.
In backend/libpq, no sense trying to protect against port->hba being
NULL after we've already dereferenced it in the switch() statement.
Prevent against possible overflow due to 32bit arithmitic in
basebackup throttling (not yet released, so no security concern).
Remove nonsensical check of array pointer against NULL in procarray.c,
looks to be a holdover from 9.1 and earlier when there were pointers
being used but now it's just an array.
Remove pointer check-against-NULL in tsearch/spell.c as we had already
dereferenced it above (in the strcmp()).
Remove dead code from adt/orderedsetaggs.c, isnull is checked
immediately after each tuplesort_getdatum() call and if true we return,
so no point checking it again down at the bottom.
Remove recently added minor error-condition memory leak in pg_regress.
A number of issues were identified by the Coverity scanner and are
addressed in this patch. None of these appear to be security issues
and many are mostly cosmetic changes.
Short comments for each of the changes follows.
Correct the semi-colon placement in be-secure.c regarding SSL retries.
Remove a useless comparison-to-NULL in proc.c (value is dereferenced
prior to this check and therefore can't be NULL).
Add checking of chmod() return values to initdb.
Fix a couple minor memory leaks in initdb.
Fix memory leak in pg_ctl- involves free'ing the config file contents.
Use an int to capture fgetc() return instead of an enum in pg_dump.
Fix minor memory leaks in pg_dump.
(note minor change to convertOperatorReference()'s API)
Check fclose()/remove() return codes in psql.
Check fstat(), find_my_exec() return codes in psql.
Various ECPG memory leak fixes.
Check find_my_exec() return in ECPG.
Explicitly ignore pqFlush return in libpq error-path.
Change PQfnumber() to avoid doing an strdup() when no changes required.
Remove a few useless check-against-NULL's (value deref'd beforehand).
Check rmtree(), malloc() results in pg_regress.
Also check get_alternative_expectfile() return in pg_regress.
The regex code didn't have any provision for query cancel; which is
unsurprising given its non-Postgres origin, but still problematic since
some operations can take a long time. Introduce a callback function to
check for a pending query cancel or session termination request, and
call it in a couple of strategic spots where we can make the regex code
exit with an error indicator.
If we ever actually split out the regex code as a standalone library,
some additional work will be needed to let the cancel callback function
be specified externally to the library. But that's straightforward
(certainly so by comparison to putting the locale-dependent character
classification logic on a similar arms-length basis), and there seems
no need to do it right now.
A bigger issue is that there may be more places than these two where
we need to check for cancels. We can always add more checks later,
now that the infrastructure is in place.
Since there are known examples of not-terribly-long regexes that can
lock up a backend for a long time, back-patch to all supported branches.
I have hopes of fixing the known performance problems later, but adding
query cancel ability seems like a good idea even if they were all fixed.
Commit abf5c5c9a4 added a bogus while-
statement after the for(;;)-loop. It went unnoticed in testing, because
it was dead code.
Report by KONDO Mitsumasa. Backpatch to 9.3. The commit that introduced
this was also applied to 9.2, but not the bogus while-loop part, because
the code in 9.2 looks quite different.
A new MAX_RATE option allows imposing a limit to the network transfer
rate from the server side. This is useful to limit the stress that
taking a base backup has on the server.
pg_basebackup is now able to specify a value to the server, too.
Author: Antonin Houska
Patch reviewed by Stefan Radomski, Andres Freund, Zoltán Böszörményi,
Fujii Masao, and Álvaro Herrera.
We were resetting the tuple's HEAP_HOT_UPDATED flag as well as t_ctid on
WAL replay of a tuple-lock operation, which is incorrect when the tuple
is already updated.
Back-patch to 9.3. The clearing of both header elements was there
previously, but since no update could be present on a tuple that was
being locked, it was harmless.
Bug reported by Peter Geoghegan and Greg Stark in
CAM3SWZTMQiCi5PV5OWHb+bYkUcnCk=O67w0cSswPvV7XfUcU5g@mail.gmail.com and
CAM-w4HPTOeMT4KP0OJK+mGgzgcTOtLRTvFZyvD0O4aH-7dxo3Q@mail.gmail.com
respectively; diagnosis by Andres Freund.
json_to_record() depends on get_call_result_type() for the tuple
descriptor of the record that should be returned, but in some cases
that cannot be determined. Add a guard to check if the tuple
descriptor has been properly resolved, similar to other callers of
get_call_result_type().
Also add guard for two other callers of get_call_result_type() in
jsonfuncs.c. Although json_to_record() is the only actual bug, it's a
good idea to follow convention.
If there are lots of uncommitted tuples at the end of the index range,
get_actual_variable_range() ends up fetching each one and doing an MVCC
visibility check on it, until it finally hits a visible tuple. This is
bad enough in isolation, considering that we don't need an exact answer
only an approximate one. But because the tuples are not yet committed,
each visibility check does a TransactionIdIsInProgress() test, which
involves scanning the ProcArray. When multiple sessions do this
concurrently, the ensuing contention results in horrid performance loss.
20X overall throughput loss on not-too-complicated queries is easy to
demonstrate in the back branches (though someone's made it noticeably
less bad in HEAD).
We can dodge the problem fairly effectively by using SnapshotDirty rather
than a normal MVCC snapshot. This will cause the index probe to take
uncommitted tuples as good, so that we incur only one tuple fetch and test
even if there are many such tuples. The extent to which this degrades the
estimate is debatable: it's possible the result is actually a more accurate
prediction than before, if the endmost tuple has become committed by the
time we actually execute the query being planned. In any case, it's not
very likely that it makes the estimate a lot worse.
SnapshotDirty will still reject tuples that are known committed dead, so
we won't give bogus answers if an invalid outlier has been deleted but not
yet vacuumed from the index. (Because btrees know how to mark such tuples
dead in the index, we shouldn't have a big performance problem in the case
that there are many of them at the end of the range.) This consideration
motivates not using SnapshotAny, which was also considered as a fix.
Note: the back branches were using SnapshotNow instead of an MVCC snapshot,
but the problem and solution are the same.
Per performance complaints from Bartlomiej Romanski, Josh Berkus, and
others. Back-patch to 9.0, where the issue was introduced (by commit
40608e7f94).
- Write HIGH:MEDIUM instead of DEFAULT:!LOW:!EXP for clarity.
- Order 3DES last to work around inappropriate OpenSSL default.
- Remove !MD5 and @STRENGTH, because they are irrelevant.
- Add clarifying documentation.
Effectively, the new default is almost the same as the old one, but it
is arguably easier to understand and modify.
Author: Marko Kreen <markokr@gmail.com>
Space trimming rather than space-padding causes unusual behavior, which
might not be standards-compliant.
Also remove recently-added now-redundant C comment.
A large majority of the callers of pg_do_encoding_conversion were
specifying the database encoding as either source or target of the
conversion, meaning that we can use the less general functions
pg_any_to_server/pg_server_to_any instead.
The main advantage of using the latter functions is that they can make use
of a cached conversion-function lookup in the common case that the other
encoding is the current client_encoding. It's notationally cleaner too in
most cases, not least because of the historical artifact that the latter
functions use "char *" rather than "unsigned char *" in their APIs.
Note that pg_any_to_server will apply an encoding verification step in
some cases where pg_do_encoding_conversion would have just done nothing.
This seems to me to be a good idea at most of these call sites, though
it partially negates the performance benefit.
Per discussion of bug #9210.
Various places assume that pg_do_encoding_conversion() and
pg_server_to_any() will ensure encoding validity of their results;
but they failed to do so in the case that the source encoding is SQL_ASCII
while the destination is not. We cannot perform any actual "conversion"
in that scenario, but we should still validate the string according to the
destination encoding. Per bug #9210 from Digoal Zhou.
Arguably this is a back-patchable bug fix, but on the other hand adding
more enforcing of encoding checks might break existing applications that
were being sloppy. On balance there doesn't seem to be much enthusiasm
for a back-patch, so fix in HEAD only.
While at it, remove some apparently-no-longer-needed provisions for
letting pg_do_encoding_conversion() "work" outside a transaction ---
if you consider it "working" to silently fail to do the requested
conversion.
Also, make a few cosmetic improvements in mbutils.c, notably removing
some Asserts that are certainly dead code since the variables they
assert aren't null are never null, even at process start. (I think
this wasn't true at one time, but it is now.)
Tablespaces can be relocated in plain backup mode by specifying one or
more -T olddir=newdir options.
Author: Steeve Lennmark <steevel@handeldsbanken.se>
Reviewed-by: Peter Eisentraut <peter_e@gmx.net>
Most estimation functions apply estimate_expression_value to see if they
can reduce an expression to a constant; the key difference is that it
allows evaluation of stable as well as immutable functions in hopes of
ending up with a simple Const node. scalararraysel didn't get the memo
though, and neither did gincost_opexpr/gincost_scalararrayopexpr. Fix
that, and remove a now-unnecessary estimate_expression_value step in the
subsidiary function scalararraysel_containment.
Per complaint from Alexey Klyukin. Back-patch to 9.3. The problem
goes back further, but I'm hesitant to change estimation behavior in
long-stable release branches.
Some of the files we optionally link in from elsewhere weren't ignored
and/or weren't cleaned up at "make clean". Noted while testing on a
machine that needs our version of snprintf.c.
The functions in slotfuncs.c don't exist in any released version,
but the changes to xlogfuncs.c represent backward-incompatibilities.
Per discussion, we're hoping that the queries using these functions
are few enough and simple enough that this won't cause too much
breakage for users.
Michael Paquier, reviewed by Andres Freund and further modified
by me.
Change input function error messages to be more consistent with what is
done elsewhere. Remove a bunch of redundant type casts, so that the
compiler will warn us if we screw up. Don't pass LSNs by value on
platforms where a Datum is only 32 bytes, per buildfarm. Move macros
for packing and unpacking LSNs to pg_lsn.h so that we can include
access/xlogdefs.h, to avoid an unsatisfied dependency on XLogRecPtr.
The SQL standard says that OVERLAPS should have a two-element row
constructor on each side. The original coding of OVERLAPS support in
our grammar attempted to extend that by allowing a single-element row
constructor, which it internally duplicated ... or tried to, anyway.
But that code has certainly not worked since our List infrastructure was
rewritten in 2004, and I'm none too sure it worked before that. As it
stands, it ends up building a List that includes itself, leading to
assorted undesirable behaviors later in the parser.
Even if it worked as intended, it'd be a bit evil because of the
possibility of duplicate evaluation of a volatile function that the user
had written only once. Given the lack of documentation, test cases, or
complaints, let's just get rid of the idea and only support the standard
syntax.
While we're at it, improve the error cursor positioning for the
wrong-number-of-arguments errors, and inline the makeOverlaps() function
since it's only called in one place anyway.
Per bug #9227 from Joshua Yanovski. Initial patch by Joshua Yanovski,
extended a bit by me.
The ASLR in Windows 8/Windows 2012 can break PostgreSQL's shared memory. It
doesn't fail every time (which is explained by the Random part in ASLR), but
can fail with errors abut failing to reserve shared memory region.
MauMau, reviewed by Craig Ringer
Coverity identified a number of places in which it couldn't prove that a
string being copied into a fixed-size buffer would fit. We believe that
most, perhaps all of these are in fact safe, or are copying data that is
coming from a trusted source so that any overrun is not really a security
issue. Nonetheless it seems prudent to forestall any risk by using
strlcpy() and similar functions.
Fixes by Peter Eisentraut and Jozef Mlich based on Coverity reports.
In addition, fix a potential null-pointer-dereference crash in
contrib/chkpass. The crypt(3) function is defined to return NULL on
failure, but chkpass.c didn't check for that before using the result.
The main practical case in which this could be an issue is if libc is
configured to refuse to execute unapproved hashing algorithms (e.g.,
"FIPS mode"). This ideally should've been a separate commit, but
since it touches code adjacent to one of the buffer overrun changes,
I included it in this commit to avoid last-minute merge issues.
This issue was reported by Honza Horak.
Security: CVE-2014-0065 for buffer overruns, CVE-2014-0066 for crypt()
Several functions, mostly type input functions, calculated an allocation
size such that the calculation wrapped to a small positive value when
arguments implied a sufficiently-large requirement. Writes past the end
of the inadvertent small allocation followed shortly thereafter.
Coverity identified the path_in() vulnerability; code inspection led to
the rest. In passing, add check_stack_depth() to prevent stack overflow
in related functions.
Back-patch to 8.4 (all supported versions). The non-comment hstore
changes touch code that did not exist in 8.4, so that part stops at 9.0.
Noah Misch and Heikki Linnakangas, reviewed by Tom Lane.
Security: CVE-2014-0064
Many server functions use the MAXDATELEN constant to size a buffer for
parsing or displaying a datetime value. It was much too small for the
longest possible interval output and slightly too small for certain
valid timestamp input, particularly input with a long timezone name.
The long input was rejected needlessly; the long output caused
interval_out() to overrun its buffer. ECPG's pgtypes library has a copy
of the vulnerable functions, which bore the same vulnerabilities along
with some of its own. In contrast to the server, certain long inputs
caused stack overflow rather than failing cleanly. Back-patch to 8.4
(all supported versions).
Reported by Daniel Schüssler, reviewed by Tom Lane.
Security: CVE-2014-0063
If the name lookups come to different conclusions due to concurrent
activity, we might perform some parts of the DDL on a different table
than other parts. At least in the case of CREATE INDEX, this can be
used to cause the permissions checks to be performed against a
different table than the index creation, allowing for a privilege
escalation attack.
This changes the calling convention for DefineIndex, CreateTrigger,
transformIndexStmt, transformAlterTableStmt, CheckIndexCompatible
(in 9.2 and newer), and AlterTable (in 9.1 and older). In addition,
CheckRelationOwnership is removed in 9.2 and newer and the calling
convention is changed in older branches. A field has also been added
to the Constraint node (FkConstraint in 8.4). Third-party code calling
these functions or using the Constraint node will require updating.
Report by Andres Freund. Patch by Robert Haas and Andres Freund,
reviewed by Tom Lane.
Security: CVE-2014-0062
The primary role of PL validators is to be called implicitly during
CREATE FUNCTION, but they are also normal functions that a user can call
explicitly. Add a permissions check to each validator to ensure that a
user cannot use explicit validator calls to achieve things he could not
otherwise achieve. Back-patch to 8.4 (all supported versions).
Non-core procedural language extensions ought to make the same two-line
change to their own validators.
Andres Freund, reviewed by Tom Lane and Noah Misch.
Security: CVE-2014-0061
Granting a role without ADMIN OPTION is supposed to prevent the grantee
from adding or removing members from the granted role. Issuing SET ROLE
before the GRANT bypassed that, because the role itself had an implicit
right to add or remove members. Plug that hole by recognizing that
implicit right only when the session user matches the current role.
Additionally, do not recognize it during a security-restricted operation
or during execution of a SECURITY DEFINER function. The restriction on
SECURITY DEFINER is not security-critical. However, it seems best for a
user testing his own SECURITY DEFINER function to see the same behavior
others will see. Back-patch to 8.4 (all supported versions).
The SQL standards do not conflate roles and users as PostgreSQL does;
only SQL roles have members, and only SQL users initiate sessions. An
application using PostgreSQL users and roles as SQL users and roles will
never attempt to grant membership in the role that is the session user,
so the implicit right to add or remove members will never arise.
The security impact was mostly that a role member could revoke access
from others, contrary to the wishes of his own grantor. Unapproved role
member additions are less notable, because the member can still largely
achieve that by creating a view or a SECURITY DEFINER function.
Reviewed by Andres Freund and Tom Lane. Reported, independently, by
Jonas Sundman and Noah Misch.
Security: CVE-2014-0060
These are needed in HEAD to make assorted contrib modules build on Windows.
Now that all the MSVC and Mingw buildfarm members seem to be on the same
page about the need for them, we can have some confidence that future
problems of this ilk will be detected promptly; there seems nothing more
to be learned by delaying this fix further.
I chose to mark QueryCancelPending as well, since it's easy to imagine code
that wants to touch ProcDiePending also caring about QueryCancelPending.
Disabling auto-import requires that all libraries we use be careful about
declspecs for exported variables; and it seems they aren't. This means
that Cygwin will not give us useful info about missing PGDLLIMPORT markers;
but it's probably sufficient that MSVC and Mingw builds do.
This is needed on Windows to support contrib/postgres_fdw. Although it's
been broken since last March, we didn't notice until recently because there
were no active buildfarm members that complained about missing PGDLLIMPORT
marking. Efforts are underway to improve that situation, in support of
which we're delaying fixing some other cases of global variables that
should be marked PGDLLIMPORT. However, this case affects 9.3, so we
can't wait any longer to fix it.
I chose to mark DateOrder as well, though it's not strictly necessary
for postgres_fdw.
We should not assume that struct timeval.tv_sec is a long, because
it ain't necessarily. (POSIX says that it's a time_t, which might
well be 64 bits now or in the future; or for that matter might be
32 bits on machines with 64-bit longs.) Per buildfarm member panther.
Back-patch to 9.3 where the dubious coding was introduced.
We used to have externs for getopt() and its API variables scattered
all over the place. Now that we find we're going to need to tweak the
variable declarations for Cygwin, it seems like a good idea to have
just one place to tweak.
In this commit, the variables are declared "#ifndef HAVE_GETOPT_H".
That may or may not work everywhere, but we'll soon find out.
Andres Freund
DST law changes in Jordan; historical changes in Cuba.
Also, remove the zones Asia/Riyadh87, Asia/Riyadh88, and Asia/Riyadh89.
Per the upstream announcement:
The files solar87, solar88, and solar89 are no longer distributed.
They were a negative experiment -- that is, a demonstration that
tz data can represent solar time only with some difficulty and error.
Their presence in the distribution caused confusion, as Riyadh
civil time was generally not solar time in those years.
Borrow the method already used by plpython. This is pretty ugly, but
it might fix the build failure exhibited by buildfarm member narwhal
since commit 846e91e022.
Hiroshi Inoue
This build technique is remarkably ugly, but that doesn't mean it has
to be unreadable too. Be a bit more liberal with the vertical whitespace,
and give the .def file a proper dependency, just in case.
If there is a WAL segment with same ID but different TLI present in both
the WAL archive and pg_xlog, prefer the one with higher TLI. Before this
patch, the archive was polled first, for all expected TLIs, and only if no
file was found was pg_xlog scanned. This was a change in behavior from 9.3,
which first scanned archive and pg_xlog for the highest TLI, then archive
and pg_xlog for the next highest TLI and so forth. This patch reverts the
behavior back to what it was in 9.2.
The reason for this is that if for example you try to do archive recovery
to timeline 2, which branched off timeline 1, but the WAL for timeline 2 is
not archived yet, we would replay past the timeline switch point on
timeline 1 using the archived files, before even looking timeline 2's files
in pg_xlog
Report and patch by Kyotaro Horiguchi. Backpatch to 9.3 where the behavior
was changed.
Adjust handleCopyOut() to stop trying to write data once it's failed
one time. For typical cases such as out-of-disk-space or broken-pipe,
additional attempts aren't going to do anything but waste time, and
in any case clean truncation of the output seems like a better behavior
than randomly dropping blocks in the middle.
Also remove dubious (and misleadingly documented) attempt to force our way
out of COPY_OUT state if libpq didn't do that. If we did have a situation
like that, it'd be a bug in libpq and would be better fixed there, IMO.
We can hope that commit fa4440f516 took care
of any such problems, anyway.
Also fix longstanding bug in handleCopyIn(): PQputCopyEnd() only supports
a non-null errormsg parameter in protocol version 3, and will actively
fail if one is passed in version 2. This would've made our attempts
to get out of COPY_IN state after a failure into infinite loops when
talking to pre-7.4 servers.
Back-patch the COPY_OUT state change business back to 9.2 where it was
introduced, and the other two fixes into all supported branches.
Previously we were piggybacking on transaction ID parameters to freeze
multixacts; but since there isn't necessarily any relationship between
rates of Xid and multixact consumption, this turns out not to be a good
idea.
Therefore, we now have multixact-specific freezing parameters:
vacuum_multixact_freeze_min_age: when to remove multis as we come across
them in vacuum (default to 5 million, i.e. early in comparison to Xid's
default of 50 million)
vacuum_multixact_freeze_table_age: when to force whole-table scans
instead of scanning only the pages marked as not all visible in
visibility map (default to 150 million, same as for Xids). Whichever of
both which reaches the 150 million mark earlier will cause a whole-table
scan.
autovacuum_multixact_freeze_max_age: when for cause emergency,
uninterruptible whole-table scans (default to 400 million, double as
that for Xids). This means there shouldn't be more frequent emergency
vacuuming than previously, unless multixacts are being used very
rapidly.
Backpatch to 9.3 where multixacts were made to persist enough to require
freezing. To avoid an ABI break in 9.3, VacuumStmt has a couple of
fields in an unnatural place, and StdRdOptions is split in two so that
the newly added fields can go at the end.
Patch by me, reviewed by Robert Haas, with additional input from Andres
Freund and Tom Lane.
We used the length of the input string, not the de-escaped string, as
the trigger for NAMEDATALEN truncation. AFAICS this would only result
in sometimes printing a phony truncation warning; but it's just luck
that there was no worse problem, since we were violating the API spec
for truncate_identifier(). Per bug #9204 from Joshua Yanovski.
This has been wrong since the Unicode-identifier support was added,
so back-patch to all supported branches.
In pqSendSome, if the connection is already closed at entry, discard any
queued output data before returning. There is no possibility of ever
sending the data, and anyway this corresponds to what we'd do if we'd
detected a hard error while trying to send(). This avoids possible
indefinite bloat of the output buffer if the application keeps trying
to send data (or even just keeps trying to do PQputCopyEnd, as psql
indeed will).
Because PQputCopyEnd won't transition out of PGASYNC_COPY_IN state
until it's successfully queued the COPY END message, and pqPutMsgEnd
doesn't distinguish a queuing failure from a pqSendSome failure,
this omission allowed an infinite loop in psql if the connection closure
occurred when we had at least 8K queued to send. It might be worth
refactoring so that we can make that distinction, but for the moment
the other changes made here seem to offer adequate defenses.
To guard against other variants of this scenario, do not allow
PQgetResult to return a PGRES_COPY_XXX result if the connection is
already known dead. Make sure it returns PGRES_FATAL_ERROR instead.
Per report from Stephen Frost. Back-patch to all active branches.
In a database that's not yet reached consistency, it's possible that some
segments of a relation are not full-size but are not the last ones either.
Because of the way smgrnblocks() works, asking for a new page with P_NEW
will fill in the last not-full-size segment --- and if that makes it full
size, the apparent EOF of the relation will increase by more than one page,
so that the next P_NEW request will yield a page past the next consecutive
one. This breaks the relation-extension logic in XLogReadBufferExtended,
possibly allowing a page update to be applied to some page far past where
it was intended to go. This appears to be the explanation for reports of
table bloat on replication slaves compared to their masters, and probably
explains some corrupted-slave reports as well.
Fix the loop to check the page number it actually got, rather than merely
Assert()'ing that dead reckoning got it to the desired place. AFAICT,
there are no other places that make assumptions about exactly which page
they'll get from P_NEW.
Problem identified by Greg Stark, though this is not the same as his
proposed patch.
It's been like this for a long time, so back-patch to all supported
branches.
If an error occurs in the foreground (backup) process of pg_basebackup,
and we exit in a controlled way, the background process (streaming
xlog process) would stay around and keep streaming.
This is evidently the default on buildfarm member narwhal, but that
is a pretty ancient Mingw version, and there is reason to think that
more recent versions of GNU ld have this feature turned on by default.
Since we are trying to achieve consistency of link behavior across
all Windows toolchains, let's just make sure here.
This is expected to make it start failing when contrib modules
reference non-PGDLLIMPORT'ed global variables, as the other Windows
build methods do. Aside from the value of consistency, the underlying
implementation of this switch is pretty ugly and not really something
we want to rely on if we have to use PGDLLIMPORT anyway for MSVC.
This should make the MSVC build act more like builds for other platforms,
i.e. backend global variables will be automatically available to loadable
libraries without need for explicit PGDLLIMPORT marking.
Craig Ringer
Get rid of use of dlltool for linking the main postgres executable.
dlltool is obsolete and we'd prefer to stop depending on it.
Also, include $(LDAP_LIBS_FE) in $(libpq_pgport). (It's not clear that
this is really needed, or why it's not a linker bug if it is needed.
But reports are that it's needed on current Cygwin.)
We might want to back-patch this if it works, but first let's see
what the buildfarm thinks.
Marco Atzeri
This results in spurious empty lines in the server log. Instead, add
the newlines only when printing out the --echo output. In some cases,
this was already done, leading to two newlines being printed. Clean
that up as well.
From: Fabrízio de Royes Mello <fabriziomello@gmail.com>
Providing this information as plain text was doubtless worth the trouble
ten years ago, but it seems likely that hardly anyone reads it in this
format anymore. And the effort required to maintain these files (in the
form of extra-complex markup rules in the relevant parts of the SGML
documentation) is significant. So, let's stop doing that and rely solely
on the other documentation formats.
Per discussion, the plain-text INSTALL instructions might still be worth
their keep, so we continue to generate that file.
Rather than remove HISTORY and src/test/regress/README from distribution
tarballs entirely, replace them with simple stub files that tell the reader
where to find the relevant documentation. This is mainly to avoid possibly
breaking packaging recipes that expect these files to exist.
Back-patch to all supported branches, because simplifying the markup
requirements for release notes won't help much unless we do it in all
branches.
WakeupWaiters() is supposed to wake up all LW_WAIT_UNTIL_FREE waiters of
the slot, but the loop incorrectly also woke up the first LW_EXCLUSIVE
waiter, if there was no LW_WAIT_UNTIL_FREE waiters in the queue.
Noted by Andres Freund. This code is new in 9.4, so no backpatching.
Make ftello error-checking consistent to all calls and remove a
bit of ftello-related code which has been #if 0'd out since 2001.
Note that we are not concerned with the ftello() call under
snprintf() failing as it is just building a string to call
exit_horribly() with; printing -1 in such a case is fine.
Rather than reset errno (or just hope that its cleared already),
check just the result of the ftello for < 0 to determine if there
was an issue.
Oversight by me, pointed out by Tom.
This prevents pg_basebackup from generating excessive output when
dumping large clusters. The status is now updated once / second,
still making it possible to see that there is progress happening,
but limiting the total bandwidth.
Mika Eloranta, reviewed by Sawada Masahiko and Oskari Saarenmaa
When using verbose mode for pg_basebackup, in tar format sent to
stdout, we'd print an unitialized buffer as the filename.
Reported by Pontus Lundkvist
Improve pg_dump by checking results on various fgetc() calls which
previously were unchecked, ditto for ftello. Also clean up a couple
of very minor memory leaks by waiting to allocate structures until
after the initial check(s).
Issues spotted by Coverity.
The shimTriConstistentFn, which calls the opclass's consistent function with
all combinations of TRUE/FALSE for any MAYBE argument, modifies the entryRes
array passed by the caller. Change startScanKey to re-initialize it between
each call to accommodate that.
It's actually a bad habit by shimTriConsistentFn to modify its argument. But
the only caller that doesn't already re-initialize the entryRes array was
startScanKey, and it's easy for startScanKey to do so. Add a comment to
shimTriConsistentFn about that.
Note: this does not give a free pass to opclass-provided consistent
functions to modify the entryRes argument; shimTriConsistent assumes that
they don't, even though it does it itself.
While at it, refactor startScanKey to allocate the requiredEntries and
additionalEntries after it knows exactly how large they need to be. Saves a
little bit of memory, and looks nicer anyway.
Per complaint by Tom Lane, buildfarm and the pg_trgm regression test.
If you have a GIN query like "rare & frequent", we currently fetch all the
items that match either rare or frequent, call the consistent function for
each item, and let the consistent function filter out items that only match
one of the terms. However, if we can deduce that "rare" must be present for
the overall qual to be true, we can scan all the rare items, and for each
rare item, skip over to the next frequent item with the same or greater TID.
That greatly speeds up "rare & frequent" type queries.
To implement that, introduce the concept of a tri-state consistent function,
where the 3rd value is MAYBE, indicating that we don't know if that term is
present. Operator classes only provide a boolean consistent function, so we
simulate the tri-state consistent function by calling the boolean function
several times, with the MAYBE arguments set to all combinations of TRUE and
FALSE. Testing all combinations is only feasible for a small number of MAYBE
arguments, but it is envisioned that we'll provide a way for operator
classes to provide a native tri-state consistent function, which can be much
more efficient. But that is not included in this patch.
We were already using that trick to for lossy pages, calling the consistent
function with the lossy entry set to TRUE and FALSE. Now that we have the
tri-state consistent function, use it for lossy pages too.
Alexander Korotkov, with fair amount of refactoring by me.
We may process relcache flush requests during transaction startup or
shutdown. In general it's not terribly safe to do catalog access at those
times, so the code's habit of trying to immediately revalidate unflushable
relcache entries is risky. Although there are no field trouble reports
that are positively traceable to this, we have been able to demonstrate
failure of the assertions recently added in RelationIdGetRelation() and
SearchCatCache(). On the other hand, it seems safe to just postpone
revalidation of the cache entry until we're inside a valid transaction.
The one case where this is questionable is where we're exiting a
subtransaction and the outer transaction is holding the relcache entry open
--- but if we made any significant changes to the rel inside such a
subtransaction, we've got problems anyway. There are mechanisms in place
to prevent that (to wit, locks for cross-session cases and
CheckTableNotInUse() for intra-session cases), so let's trust to those
mechanisms to keep us out of trouble.
Commit 42c80c696e added an
Assert(IsTransactionState()) in SearchCatCache(), to catch
any code that thought it could do a catcache lookup outside
transactions. Extend the same idea to relcache lookups.
These flushes were added in my commit d2896a9ed, which added the btree
logic that keeps a cached copy of the index metapage data in index relcache
entries. The idea was to ensure that other backends would promptly update
their cached copies after a change. However, this is not really necessary,
since _bt_getroot() has adequate defenses against believing a stale root
page link, and _bt_getrootheight() doesn't have to be 100% right.
Moreover, if it were necessary, a relcache flush would be an unreliable way
to do it, since the sinval mechanism believes that relcache flush requests
represent transactional updates, and therefore discards them on transaction
rollback. Therefore, we might as well drop these flush requests and save
the time to rebuild the whole relcache entry after a metapage change.
If we ever try to support in-place truncation of btree indexes, it might
be necessary to revisit this issue so that _bt_getroot() can't get caught
by trying to follow a metapage link to a page that no longer exists.
A possible solution to that is to make use of an smgr, rather than
relcache, inval request to force other backends to discard their cached
metapages. But for the moment this is not worth pursuing.
Commit a5ff502fce was a brick shy of a load
in the backend lexer too, not just psql. Per further testing of bug #9068.
In passing, improve related comments.
Given a composite-type parameter named x, "$1.*" worked fine, but "x.*"
not so much. This has been broken since named parameter references were
added in commit 9bff0780cf, so patch back
to 9.2. Per bug #9085 from Hardy Falk.
The temporary statistics files don't need to be included in the backup
because they are always reset at the beginning of the archive recovery.
This patch changes pg_basebackup so that it skips all files located in
$PGDATA/pg_stat_tmp or the directory specified by stats_temp_directory
parameter.
Remove unused copy-and-pasted macro definitions, and improve formatting
of recently-added productions.
I got interested in this because buildfarm member protosciurus has been
crashing in "bison repl_gram.y" since commit 858ec11. It's a long shot
that this will fix that, though maybe the missing trailing semicolon
has something to do with it? In any case, there's no need to approve
of dead code, nor of code whose formatting isn't even self-consistent
let alone consistent with what's around it.
In p_isdigit and other character class test functions generated by the
p_iswhat macro, the code path for non-C locales with multibyte encodings
contained a bogus pointer cast that would accidentally fail to malfunction
if types wchar_t and wint_t have the same width. Apparently that is true
on most platforms, but not on recent Cygwin releases. Remove the cast,
as it seems completely unnecessary (I think it arose from a false analogy
to the need to cast to unsigned char when dealing with the <ctype.h>
functions). Per bug #8970 from Marco Atzeri.
In the same functions, the code path for C locale with a multibyte encoding
simply ANDed each wide character with 0xFF before passing it to the
corresponding <ctype.h> function. This could result in false positive
answers for some non-ASCII characters, so use a range test instead.
Noted by me while investigating Marco's complaint.
Also, remove some useless though not actually buggy maskings and casts
in the hand-coded p_isalnum and p_isalpha functions, which evidently
got tested a bit more carefully than the macro-generated functions.
WalSndKill was doing things exactly backwards: it should first clear
MyWalSnd (to stop signal handlers from touching MyWalSnd->latch),
then disown the latch, and only then mark the WalSnd struct unused by
clearing its pid field.
Also, WalRcvSigUsr1Handler and worker_spi_sighup failed to preserve
errno, which is surely a requirement for any signal handler.
Per discussion of recent buildfarm failures. Back-patch as far
as the relevant code exists.
The preferred method is to use "cc -shared", and this allows binaries
to be rebased if required, unlike dllwrap.
Backpatch to 9.0 where we have buildfarm coverage.
There are still some issues with Cygwin, especially modern Cygwin, but
this helps us get closer to good support.
Marco Atzeri.
This has long been done by the MSVC build system, and has caused
confusion in the past when programs like psql have failed to start
because they can't find the DLL. If it's in the same directory as it now
will be they will find it.
Backpatch to all live branches.
Previously an input array string that started with a single-element
array dimension would then later accept a multi-dimensional segment.
BACKWARD INCOMPATIBILITY
Replication slots are a crash-safe data structure which can be created
on either a master or a standby to prevent premature removal of
write-ahead log segments needed by a standby, as well as (with
hot_standby_feedback=on) pruning of tuples whose removal would cause
replication conflicts. Slots have some advantages over existing
techniques, as explained in the documentation.
In a few places, we refer to the type of replication slots introduced
by this patch as "physical" slots, because forthcoming patches for
logical decoding will also have slots, but with somewhat different
properties.
Andres Freund and Robert Haas
Evidence from buildfarm member crake suggests that the new test_shm_mq
module is routinely crashing the server due to the arrival of a SIGUSR1
after the shared memory segment has been unmapped. Although processes
using the new dynamic background worker facilities are more likely to
receive a SIGUSR1 around this time, the problem is also possible on older
branches, so I'm back-patching the parts of this change that apply to
older branches as far as they apply.
It's already generally the case that code checks whether these pointers
are NULL before deferencing them, so the important thing is mostly to
make sure that they do get set to NULL before they become invalid. But
in master, there's one case in procsignal_sigusr1_handler that lacks a
NULL guard, so add that.
Patch by me; review by Tom Lane.
Commit 820f08cabd claimed to make the server
and libpq handle SSL protocol versions identically, but actually the server
was still accepting SSL v3 protocol while libpq wasn't. Per discussion,
SSL v3 is obsolete, and there's no good reason to continue to accept it.
So make the code really equivalent on both sides. The behavior now is
that we use the highest mutually-supported TLS protocol version.
Marko Kreen, some comment-smithing by me
When pulling a "postponed" qual from a LATERAL subquery up into the quals
of an outer join, we must make sure that the postponed qual is included
in those seen by make_outerjoininfo(). Otherwise we might compute a
too-small min_lefthand or min_righthand for the outer join, leading to
"JOIN qualification cannot refer to other relations" failures from
distribute_qual_to_rels. Subtler errors in the created plan seem possible,
too, if the extra qual would only affect join ordering constraints.
Per bug #9041 from David Leverton. Back-patch to 9.3.
New checks include input, month/day/time internal adjustments, addition,
subtraction, multiplication, and negation. Also adjust docs to
correctly specify interval size in bytes.
Report from Rok Kralj
Various places were supposing that errno could be expected to hold still
within an ereport() nest or similar contexts. This isn't true necessarily,
though in some cases it accidentally failed to fail depending on how the
compiler chanced to order the subexpressions. This class of thinko
explains recent reports of odd failures on clang-built versions, typically
missing or inappropriate HINT fields in messages.
Problem identified by Christian Kruse, who also submitted the patch this
commit is based on. (I fixed a few issues in his patch and found a couple
of additional places with the same disease.)
Back-patch as appropriate to all supported branches.
This doesn't work for prepared queries, but it's not too easy to get
the information in that case and there's some debate as to exactly
what the right thing to measure is, so just do this for now.
Andreas Karlsson, with slight doc changes by me.
We calculated the rounded-up size for the allocation, but then failed to
use the rounded-up value in the mmap() call. Oops.
Also, initialize allocsize, to silence warnings seen with some compilers,
as pointed out by Jeff Janes.
When skipping over some items in a posting tree, re-find the new location
by descending the tree from root, rather than walking the right links.
This can save a lot of I/O.
Heavily modified from Alexander Korotkov's fast scan patch.
If we're skipping past a certain TID, avoid decoding posting list segments
that only contain smaller TIDs.
Extracted from Alexander Korotkov's fast scan patch, heavily modified.
In a multi-key search, ie. something like "col @> 'foo' AND col @> 'bar'",
as soon as we find the next item that matches the first criteria, we don't
need to check the second criteria for TIDs smaller the first match. That
saves a lot of effort, especially if one of the terms is rare, while the
second occurs very frequently.
Based on ideas from Alexander Korotkov's fast scan patch.
This patch adds an option, huge_tlb_pages, which allows requesting the
shared memory segment to be allocated using huge pages, by using the
MAP_HUGETLB flag in mmap(). This can improve performance.
The default is 'try', which means that we will attempt using huge pages,
and fall back to non-huge pages if it doesn't work. Currently, only Linux
has MAP_HUGETLB. On other platforms, the default 'try' behaves the same as
'off'.
In the passing, don't try to round the mmap() size to a multiple of
pagesize. mmap() doesn't require that, and there's no particular reason for
PostgreSQL to do that either. When using MAP_HUGETLB, however, round the
request size up to nearest 2MB boundary. This is to work around a bug in
some Linux kernel versions, but also to avoid wasting memory, because the
kernel will round the size up anyway.
Many people were involved in writing this patch, including Christian Kruse,
Richard Poole, Abhijit Menon-Sen, reviewed by Peter Geoghegan, Andres Freund
and me.
json_build_array() and json_build_object allow for the construction of
arbitrarily complex json trees. json_object() turns a one or two
dimensional array, or two separate arrays, into a json_object of
name/value pairs, similarly to the hstore() function.
json_object_agg() aggregates its two arguments into a single json object
as name value pairs.
Catalog version bumped.
Andrew Dunstan, reviewed by Marko Tiikkaja.
Per the expanded comment-
As we're just trying to reset these to go to DEVNULL, there's not
much point in checking for failure from the close/dup2 calls here,
if they fail then presumably the file descriptors are closed and
any writes will go into the bitbucket anyway.
Pointed out by Tom.
It's worth distinguishing these cases from run-of-the-mill wrong-password
problems, since users have been known to waste lots of time pursuing the
wrong theory about what's failing. Now, our longstanding policy about how
to report authentication failures is that we don't really want to tell the
*client* such things, since that might be giving information to a bad guy.
But there's nothing wrong with reporting the details to the postmaster log,
and indeed the comments in this area of the code contemplate that
interesting details should be so reported. We just weren't handling these
particular interesting cases usefully.
To fix, add infrastructure allowing subroutines of ClientAuthentication()
to return a string to be added to the errdetail_log field of the main
authentication-failed error report. We might later want to use this to
report other subcases of authentication failure the same way, but for the
moment I just dealt with password cases.
Per discussion of a patch from Josh Drake, though this is not what
he proposed.
This makes it possible to store lwlocks as part of some other data
structure in the main shared memory segment, or in a dynamic shared
memory segment. There is still a main LWLock array and this patch does
not move anything out of it, but it provides necessary infrastructure
for doing that in the future.
This change is likely to increase the size of LWLockPadded on some
platforms, especially 32-bit platforms where it was previously only
16 bytes.
Patch by me. Review by Andres Freund and KaiGai Kohei.
Fix integer overflow issue noted by Magnus Hagander, as well as a bunch
of other infelicities in commit ee1e5662d8
and its unreasonably large number of followups.
Move allocation to after we check the remote server version, to avoid
a possible, very minor, memory leak. This makes us more consistent
throughout as most places in pg_dump are done in the same way (due, in
part, to previous fixes like this).
Spotted by the Coverity scanner.
Consistently check the dup2() call results throughout syslogger.c.
It's pretty unlikely that they'll error out, but if they do,
ereport(FATAL) instead of blissfully continuing on.
Spotted by the Coverity scanner.