In constructs such as "x IN (1,2,3,4)" and "x <> ALL(ARRAY[1,2,3,4])",
we formerly always used a general-purpose assumption that the probability
of success is independent for each comparison of "x" to an array element.
But in real-world usage of these constructs, that's a pretty poor
assumption; it's much saner to assume that the array elements are distinct
and so the match probabilities are disjoint. Apply that assumption if the
operator appears to behave as equality (for ANY) or inequality (for ALL).
But fall back to the normal independent-probabilities calculation if this
yields an impossible result, ie probability > 1 or < 0. We could protect
ourselves against bad estimates even more by explicitly checking for equal
array elements, but that is expensive and doesn't seem worthwhile: doing
it would amount to optimizing for poorly-written queries at the expense
of well-written ones.
Daniele Varrazzo and Tom Lane, after a suggestion by Ants Aasma
GetForeignColumnOptions provides some abstraction for accessing
column-specific FDW options, on a par with the access functions that were
already provided here for other FDW-related information.
Adjust file_fdw.c to use GetForeignColumnOptions instead of equivalent
hand-rolled code.
In addition, add some SGML documentation for the functions exported by
foreign.c that are meant for use by FDW authors.
(This is the fdw_helper portion of the proposed pgsql_fdw patch.)
Hanada Shigeru, reviewed by KaiGai Kohei
Now that cache invalidation callbacks get only a hash value, and not a
tuple TID (per commits 632ae6829f and
b5282aa893), the only way they can restrict
what they invalidate is to know what the hash values mean. setrefs.c was
doing this via a hard-wired assumption but that seems pretty grotty, and
it'll only get worse as more cases come up. So let's expose a calculation
function that takes the same parameters as SearchSysCache. Per complaint
from Marko Kreen.
Use-cases for this include custom log filtering rules and custom log
message transmission mechanisms (for instance, lossy log message
collection, which has been discussed several times recently).
As is our common practice for hooks, there's no regression test nor
user-facing documentation for this, though the author did exhibit a
sample module using the hook.
Martin Pihlak, reviewed by Marti Raudsepp
This simplifies the code a little bit. The new rule is that to update
XLogCtl->LogwrtResult, you must hold both WALWriteLock and info_lck, whereas
before we had two copies, one that was protected by WALWriteLock and another
protected by info_lck. The code that updates them was already holding both
locks, so merging the two is trivial.
The third copy, XLogCtl->Insert.LogwrtResult, was not totally redundant, it
was used in AdvanceXLInsertBuffer to update the backend-local copy, before
acquiring the info_lck to read the up-to-date value. But the value of that
seems dubious; at best it's saving one spinlock acquisition per completed
WAL page, which is not significant compared to all the other work involved.
And in practice, it's probably not saving even that much.
It's harmless to do full page writes even when not strictly necessary, so
when turning full_page_writes on, we can set the global flag first, and then
call XLogInsert. Likewise, when turning it off, we can write the WAL record
first, and then clear the flag. This way XLogInsert doesn't need any special
handling of the XLOG_FPW_CHANGE record type. XLogInsert is complicated
enough already, so anything we can keep away from there is a good thing.
Actually I don't think the atomicity of the shared memory flag matters,
anyway, because we only write the XLOG_FPW_CHANGE at the end of recovery,
when there are no concurrent WAL insertions going on. But might as well make
it safe, in case we allow changing full_page_writes on the fly in the
future.
The original API specification only allowed an FDW to create a single
access path, which doesn't seem like a terribly good idea in hindsight.
Instead, move the responsibility for building the Path node and calling
add_path() into the FDW's PlanForeignScan function. Now, it can do that
more than once if appropriate. There is no longer any need for the
transient FdwPlan struct, so get rid of that.
Etsuro Fujita, Shigeru Hanada, Tom Lane
This patch installs significantly smarter penalty and picksplit functions
for ranges, making GiST indexes for them smaller and faster to search.
There is no on-disk format change, so no catversion bump, but you'd need
to REINDEX to get the benefits for any existing index.
Alexander Korotkov, reviewed by Jeff Davis
The code in this function that tried to cope with a missing count histogram
was quite ineffective for anything except a perfectly flat distribution.
Furthermore, since we were already punting for missing MCELEM slot, it's
rather useless to sweat over missing DECHIST: there are no cases where
ANALYZE will create the first but not the second. So just simplify the
code by punting rather than pretending we can do something useful.
Do "frac" arithmetic in int64 to prevent overflow with large statistics
targets, and improve the comments so people have some chance of
understanding how it works.
Alexander Korotkov and Tom Lane
Now that we have validate_xlog_location, call it from the previously
existing functions taking xlog locatoins as a string input.
Suggested by Fujii Masao
Comparing two xlog locations are useful for example when calculating
replication lag.
Euler Taveira de Oliveira, reviewed by Fujii Masao, and some cleanups
from me
This patch improves selectivity estimation for the array <@, &&, and @>
(containment and overlaps) operators. It enables collection of statistics
about individual array element values by ANALYZE, and introduces
operator-specific estimators that use these stats. In addition,
ScalarArrayOpExpr constructs of the forms "const = ANY/ALL (array_column)"
and "const <> ANY/ALL (array_column)" are estimated by treating them as
variants of the containment operators.
Since we still collect scalar-style stats about the array values as a
whole, the pg_stats view is expanded to show both these stats and the
array-style stats in separate columns. This creates an incompatible change
in how stats for tsvector columns are displayed in pg_stats: the stats
about lexemes are now displayed in the array-related columns instead of the
original scalar-related columns.
There are a few loose ends here, notably that it'd be nice to be able to
suppress either the scalar-style stats or the array-element stats for
columns for which they're not useful. But the patch is in good enough
shape to commit for wider testing.
Alexander Korotkov, reviewed by Noah Misch and Nathan Boley
The only reason this didn't work before was that parserOpenTable()
rejects composite types. So use relation_openrv() directly and
manually do the errposition() setup that parserOpenTable() does.
This fixes an oversight in commit 11cad29c91,
which introduced MergeAppend plans. Before that happened, we never
particularly cared about the sort ordering of scans of inheritance child
relations, since appending their outputs together would destroy any
ordering anyway. But now it's important to be able to match child relation
sort orderings to those of the surrounding query. The original coding of
add_child_rel_equivalences skipped ec_has_const EquivalenceClasses, on the
originally-correct grounds that adding child expressions to them was
useless. The effect of this is that when a parent variable is equated to
a constant, we can't recognize that index columns on the equivalent child
variables are not sort-significant; that is, we can't recognize that a
child index on, say, (x, y) is able to generate output in "ORDER BY y"
order when there is a clause "WHERE x = constant". Adding child
expressions to the (x, constant) EquivalenceClass fixes this, without any
downside that I can see other than a few more planner cycles expended on
such queries.
Per recent gripe from Robert McGehee. Back-patch to 9.1 where MergeAppend
was introduced.
Previously it was thought that it's impossible as the code stands, because
insertions create buffers as tuples are cascaded downwards, and index
split also creaters buffers eagerly for all halves. But the example from
Jay Levitt demonstrates that it can happen, when the root page is split.
It's in fact OK if the buffer doesn't exist, so we just need to remove the
sanity check. In fact, we've been discussing the possibility of destroying
empty buffers to conserve memory, which would render the sanity check
completely useless anyway.
Fix by Alexander Korotkov
The only toastable column now is datacl, but we don't really support
long ACLs anyway. The TOAST table should have been removed when the
pg_db_role_setting catalog was introduced in commit
2eda8dfb52, but I forgot to do that.
Per -hackers discussion on March 2011.
A prepared transaction can get new conflicts in and out after preparing, so
we cannot rely on the in- and out-flags stored in the statefile at prepare-
time. As a quick fix, make the conservative assumption that after a restart,
all prepared transactions are considered to have both in- and out-conflicts.
That can lead to unnecessary rollbacks after a crash, but that shouldn't be
a big problem in practice; you don't want prepared transactions to hang
around for a long time anyway.
Dan Ports
This makes it much more convenient to build tools for Postgres that are
separately compiled and require a matching CRC implementation.
To prevent multiple copies of the CRC polynomial tables being introduced
into the postgres binaries, they are now included in the static library
libpgport that is mainly meant for replacement system functions. That
seems like a bit of a kludge, but there's no better place.
This cleans up building of the tools pg_controldata and pg_resetxlog,
which previously had to build their own copies of pg_crc.o.
In the future, external programs that need access to the CRC tables can
include the tables directly from the new header file pg_crc_tables.h.
Daniel Farina, reviewed by Abhijit Menon-Sen and Tom Lane
We don't need to constrain the other side of an indexable join clause to
not be below an outer join; an example here is
SELECT FROM t1 LEFT JOIN t2 ON t1.a = t2.b LEFT JOIN t3 ON t2.c = t3.d;
We can consider an inner indexscan on t3.d using c = d as indexqual, even
though t2.c is potentially nulled by a previous outer join. The comparable
logic in orindxpath.c has always worked that way, but I was being overly
cautious here.
We already skip rewriting the table in these cases, but we still force a
whole table scan to validate the data. This can be skipped, and thus
we can make the whole ALTER TABLE operation just do some catalog touches
instead of scanning the table, when these two conditions hold:
(a) Old and new pg_constraint.conpfeqop match exactly. This is actually
stronger than needed; we could loosen things by way of operator
families, but it'd require a lot more effort.
(b) The functions, if any, implementing a cast from the foreign type to
the primary opcintype are the same. For this purpose, we can consider a
binary coercion equivalent to an exact type match. When the opcintype
is polymorphic, require that the old and new foreign types match
exactly. (Since ri_triggers.c does use the executor, the stronger check
for polymorphic types is no mere future-proofing. However, no core type
exercises its necessity.)
Author: Noah Misch
Committer's note: catalog version bumped due to change of the Constraint
node. I can't actually find any way to have such a node in a stored
rule, but given that we have "out" support for them, better be safe.
In commit 4016bdef8a I fixed a bunch of
ginxlog.c bugs having to do with not handling XLogReadBuffer failures
correctly. However, in ginRedoUpdateMetapage and ginRedoDeleteListPages,
I unaccountably thought that failure to read the metapage would be
impossible and just put in an elog(PANIC) call. This is of course wrong:
failure is exactly what will happen if the index got dropped (or rebuilt)
between creation of the WAL record and the crash we're trying to recover
from. I believe this explains Nicholas Wilson's recent report of these
errors getting reached.
Also, fix memory leak in forgetIncompleteSplit. This wasn't of much
concern when the code was written, but in a long-running standby server
page split records could be expected to accumulate indefinitely.
Back-patch to 8.4 --- before that, GIN didn't have a metapage.
Claiming that the typevar argument to DefineCompositeType() is const
was a plain lie. A similar case in DefineVirtualRelation() was
already changed in passing in commit 1575fbcb. Also clean up the now
unnecessary casts that used to cast away the const.
The "uncomplicated" case isn't materially less complicated than the full
case, certainly not enough so to justify duplicating nearly 500 lines
of code. The only extra work being done in the full path is zaptreesubs,
which is very cheap compared to everything else being done here, and
besides that I'm less than convinced that it's not needed in some cases
even without backrefs.
In nested sub-regex trees, lower-level nodes created DFAs and then
destroyed them again before exiting, which is a bit dumb considering that
the recursive search is likely to call those nodes again later. Instead
cache each created DFA until the end of pg_regexec(). This is basically a
space for time tradeoff, in that it might increase the maximum memory
usage. However, in most regex patterns there are not all that many subre
nodes, so not that many DFAs --- and in any case, the peak usage occurs
when reaching the bottom recursion level, and except for alternation cases
that's going to be the same anyway.
Apparently some primordial version of Spencer's engine needed cdissect()
and child functions to be able to continue matching from a previous
position when re-called. That is dead code, though, since trivial
inspection shows that cdissect can never be entered without having
previously done zapmem which resets the relevant retry counter. I have
also verified experimentally that no case in the Tcl regression tests
reaches cdissect with a nonzero retry value. Accordingly, remove that
logic. This doesn't really save any noticeable number of cycles in itself,
but it is one step towards making dissect() and cdissect() equivalent,
which will allow removing hundreds of lines of near-duplicated code.
Since struct subre's "retry" field is no longer particularly related to
any kind of retry, rename it to "id". As of this commit it's only used
for identifying a subre node in debug printouts, so you might think we
should get rid of the field entirely; but I have a plan for another use.
Cases where a back-reference is part of a larger subexpression that
is quantified have never worked in Spencer's regex engine, because
he used a compile-time transformation that neglected the need to
check the back-reference match in iterations before the last one.
(That was okay for capturing parens, and we still do it if the
regex has *only* capturing parens ... but it's not okay for backrefs.)
To make this work properly, we have to add an "iteration" node type
to the regex engine's vocabulary of sub-regex nodes. Since this is a
moderately large change with a fair risk of introducing new bugs of its
own, apply to HEAD only, even though it's a fix for a longstanding bug.
Both libpq and the backend would truncate a common name extracted from a
certificate at 32 bytes. Replace that fixed-size buffer with dynamically
allocated string so that there is no hard limit. While at it, remove the
code for extracting peer_dn, which we weren't using for anything; and
don't bother to store peer_cn longer than we need it in libpq.
This limit was not so terribly unreasonable when the code was written,
because we weren't using the result for anything critical, just logging it.
But now that there are options for checking the common name against the
server host name (in libpq) or using it as the user's name (in the server),
this could result in undesirable failures. In the worst case it even seems
possible to spoof a server name or user name, if the correct name is
exactly 32 bytes and the attacker can persuade a trusted CA to issue a
certificate in which that string is a prefix of the certificate's common
name. (To exploit this for a server name, he'd also have to send the
connection astray via phony DNS data or some such.) The case that this is
a realistic security threat is a bit thin, but nonetheless we'll treat it
as one.
Back-patch to 8.4. Older releases contain the faulty code, but it's not
a security problem because the common name wasn't used for anything
interesting.
Reported and patched by Heikki Linnakangas
Security: CVE-2012-0867
This check was overlooked when we added function execute permissions to the
system years ago. For an ordinary trigger function it's not a big deal,
since trigger functions execute with the permissions of the table owner,
so they couldn't do anything the user issuing the CREATE TRIGGER couldn't
have done anyway. However, if a trigger function is SECURITY DEFINER,
that is not the case. The lack of checking would allow another user to
install it on his own table and then invoke it with, essentially, forged
input data; which the trigger function is unlikely to realize, so it might
do something undesirable, for instance insert false entries in an audit log
table.
Reported by Dinesh Kumar, patch by Robert Haas
Security: CVE-2012-0866
This allows changing the location of the files that were previously
hard-coded to server.crt, server.key, root.crt, root.crl.
server.crt and server.key continue to be the default settings and are
thus required to be present by default if SSL is enabled. But the
settings for the server-side CA and CRL are now empty by default, and
if they are set, the files are required to be present. This replaces
the previous behavior of ignoring the functionality if the files were
not found.
When "vacuuming" a single btree page by removing LP_DEAD tuples, we are not
actually within a vacuum operation, but rather in an ordinary insertion
process that could well be running concurrently with a vacuum. So clearing
the cycleid is incorrect, and could cause the concurrent vacuum to miss
removing tuples that it needs to remove. This is a longstanding bug
introduced by commit e6284649b9 of
2006-07-25. I believe it explains Maxim Boguk's recent report of index
corruption, and probably some other previously unexplained reports.
In 9.0 and up this is a one-line fix; before that we need to introduce a
flag to tell _bt_delitems what to do.
First, as noted by Itagaki Takahiro, a datum of type JSON doesn't
need to be escaped. Second, ensure that numeric output not in
the form of a legal JSON number is quoted and escaped.
The syntax "\n*", that is a backref with a * quantifier directly applied
to it, has never worked correctly in Spencer's library. This has been an
open bug in the Tcl bug tracker since 2005:
https://sourceforge.net/tracker/index.php?func=detail&aid=1115587&group_id=10894&atid=110894
The core of the problem is in parseqatom(), which first changes "\n*" to
"\n+|" and then applies repeat() to the NFA representing the backref atom.
repeat() thinks that any arc leading into its "rp" argument is part of the
sub-NFA to be repeated. Unfortunately, since parseqatom() already created
the arc that was intended to represent the empty bypass around "\n+", this
arc gets moved too, so that it now leads into the state loop created by
repeat(). Thus, what was supposed to be an "empty" bypass gets turned into
something that represents zero or more repetitions of the NFA representing
the backref atom. In the original example, in place of
^([bc])\1*$
we now have something that acts like
^([bc])(\1+|[bc]*)$
At runtime, the branch involving the actual backref fails, as it's supposed
to, but then the other branch succeeds anyway.
We could no doubt fix this by some rearrangement of the operations in
parseqatom(), but that code is plenty ugly already, and what's more the
whole business of converting "x*" to "x+|" probably needs to go away to fix
another problem I'll mention in a moment. Instead, this patch suppresses
the *-conversion when the target is a simple backref atom, leaving the case
of m == 0 to be handled at runtime. This makes the patch in regcomp.c a
one-liner, at the cost of having to tweak cbrdissect() a little. In the
event I went a bit further than that and rewrote cbrdissect() to check all
the string-length-related conditions before it starts comparing characters.
It seems a bit stupid to possibly iterate through many copies of an
n-character backreference, only to fail at the end because the target
string's length isn't a multiple of n --- we could have found that out
before starting. The existing coding could only be a win if integer
division is hugely expensive compared to character comparison, but I don't
know of any modern machine where that might be true.
This does not fix all the problems with quantified back-references. In
particular, the code is still broken for back-references that appear within
a larger expression that is quantified (so that direct insertion of the
quantification limits into the BACKREF node doesn't apply). I think fixing
that will take some major surgery on the NFA code, specifically introducing
an explicit iteration node type instead of trying to transform iteration
into concatenation of modified regexps.
Back-patch to all supported branches. In HEAD, also add a regression test
case for this. (It may seem a bit silly to create a regression test file
for just one test case; but I'm expecting that we will soon import a whole
bunch of regex regression tests from Tcl, so might as well create the
infrastructure now.)
While this doesn't save a huge amount of runtime, it still seems worth
doing, especially since I realized that the data copying I did in my first
draft was quite unnecessary. In this version, once we have the results
cached, getting them back for re-use is really very cheap.
Also, remove the hard-wired limitation to not consider wctype.h results for
character codes above 255. It turns out that we can't push the limit as
far up as I'd originally hoped, because the regex colormap code is not
efficient enough to cope very well with character classes containing many
thousand letters, which a Unicode locale is entirely capable of producing.
Still, we can push it up to U+7FF (which I chose as the limit of 2-byte
UTF8 characters), which will at least make Eastern Europeans happy pending
a better solution. Thus, this commit resolves the specific complaint in
bug #6457, but not the more general issue that letters of non-western
alphabets are mostly not recognized as matching [[:alpha:]].
Create src/backend/regex/README to hold an implementation overview of
the regex package, and fill it in with some preliminary notes about
the code's DFA/NFA processing and colormap management. Much more to
do there of course.
Also, improve some code comments around the colormap and cvec code.
No functional changes except to add one missing assert.
Some line feeds are added to target lists and from lists to make
them more readable. By default they wrap at 80 columns if possible,
but the wrap column is also selectable - if 0 it wraps after every
item.
Andrew Dunstan, reviewed by Hitoshi Harada.
Sync our regex code with upstream changes since last time we did this,
which was Tcl 8.5.0 (see commit df1e965e12).
There are no functional changes here; the main point is just to lay down
a commit-log marker that somebody has looked at this recently, and to do
what we can to keep the two codebases comparable.
Formerly, we just punted when trying to estimate stats for variables coming
out of sub-queries using DISTINCT, on the grounds that whatever stats we
might have for underlying table columns would be inapplicable. But if the
sub-query has only one DISTINCT column, we can consider its output variable
as being unique, which is useful information all by itself. The scope of
this improvement is pretty narrow, but it costs nearly nothing, so we might
as well do it. Per discussion with Andres Freund.
This patch differs from the draft I submitted yesterday in updating various
comments about vardata.isunique (to reflect its extended meaning) and in
tweaking the interaction with security_barrier views. There does not seem
to be a reason why we can't use this sort of knowledge even when the
sub-query is such a view.
This extends the changes of commit 6252c4f9e2
so that we run the cleanup hook earlier for failure cases as well as
success cases. As before, the point is to avoid an assertion failure from
an Assert I added in commit a874fe7b4c, which
was meant to check that no user-written code can be called during portal
cleanup. This fixes a case reported by Pavan Deolasee in which the Assert
could be triggered during backend exit (see the new regression test case),
and also prevents the possibility that the cleanup hook is run after
portions of the portal's state have already been recycled. That doesn't
really matter in current usage, but it foreseeably could matter in the
future.
Back-patch to 9.1 where the Assert in question was added.
Per recent work by Peter Geoghegan, it's significantly faster to
tuplesort on a single sortkey if ApplySortComparator is inlined into
quicksort rather reached via a function pointer. It's also faster
in general to have a version of quicksort which is specialized for
sorting SortTuple objects rather than objects of arbitrary size and
type. This requires a couple of additional copies of the quicksort
logic, which in this patch are generate using a Perl script. There
might be some benefit in adding further specializations here too,
but thus far it's not clear that those gains are worth their weight
in code footprint.
The hstore and json datatypes both have record-conversion functions that
pay attention to column names in the composite values they're handed.
We used to not worry about inserting correct field names into tuple
descriptors generated at runtime, but given these examples it seems
useful to do so. Observe the nicer-looking results in the regression
tests whose results changed.
catversion bump because there is a subtle change in requirements for stored
rule parsetrees: RowExprs from ROW() constructs now have to include field
names.
Andrew Dunstan and Tom Lane
We don't normally allow quals to be pushed down into a view created
with the security_barrier option, but functions without side effects
are an exception: they're OK. This allows much better performance in
common cases, such as when using an equality operator (that might
even be indexable).
There is an outstanding issue here with the CREATE FUNCTION / ALTER
FUNCTION syntax: there's no way to use ALTER FUNCTION to unset the
leakproof flag. But I'm committing this as-is so that it doesn't
have to be rebased again; we can fix up the grammar in a future
commit.
KaiGai Kohei, with some wordsmithing by me.
If tuples were toasted, heap_multi_insert didn't update the ctid on the
original tuples. This caused a failure if there was an after trigger
(including a foreign key), on the table, and a tuple got toasted.
Per off-list report and test case from Ted Phelps
It's not entirely evident how the logic here relates to the
interval_transform function, so let's clue people in that they need to
check that if the rules change.
These were added to kwlist.h as unreserved keywords in separate patches,
but authors forgot to add them to the corresponding list in gram.y.
Because of that, even though they were supposed to be unreserved keywords,
they could not be used as identifiers. src/tools/check_keywords.pl is your
friend.
If somebody puts a window function in WHERE, we should complain about that
in so many words. The previous coding tended to complain about the window
function's arguments instead, which is likely to be misleading to users who
are unclear on the semantics of window functions; as seen for example in
bug #6440 from Matyas Novak.
Just another example of how "add new code at the end" is frequently a bad
heuristic.
This enables ALTER TABLE to skip table and index rebuilds when the
new type is unconstraint varbit, or when the allowable number of bits
is not decreasing.
Noah Misch, with review and a fix for an OID collision by me.
This enables ALTER TABLE to skip table and index rebuilds when a column
is changed to an unconstrained numeric, or when the scale is unchanged
and the precision does not decrease.
Noah Misch, with a few stylistic changes and a fix for an OID
collision by me.
Sometimes it may be useful to get actual row counts out of EXPLAIN
(ANALYZE) without paying the cost of timing every node entry/exit.
With this patch, you can say EXPLAIN (ANALYZE, TIMING OFF) to get that.
Tomas Vondra, reviewed by Eric Theise, with minor doc changes by me.
If LWLockWaitUntilFree was called before the first LWLockAcquire call, you
would either crash because of access to uninitialized array or account the
acquisition incorrectly. LWLockConditionalAcquire doesn't have this problem
because it doesn't update the lwlock stats.
In practice, this never happens because there is no codepath where you would
call LWLockWaitUntilfree before LWLockAcquire after a new process is
launched. But that's just accidental, there's no guarantee that that's
always going to be true in the future.
Spotted by Jeff Janes.
The postmaster was coded to treat any unexpected exit of the startup
process (i.e., the WAL replay process) as a catastrophic crash, and not try
to restart it. This was OK so long as the startup process could not have
any sibling postmaster children. However, if a hot-standby backend
crashes, we SIGQUIT the startup process along with everything else, and the
resulting exit is hardly "unexpected". Treating it as such meant we failed
to restart a standby server after any child crash at all, not only a crash
of the WAL replay process as intended. Adjust that. Back-patch to 9.0
where hot standby was introduced.
Although we will not even issue an XLOG_TBLSPC_DROP WAL record unless
removal of the tablespace's directories succeeds, that does not guarantee
that the same operation will succeed during WAL replay. Foreseeable
reasons for it to fail include temp files created in the tablespace by Hot
Standby backends, wrong directory permissions on a standby server, etc etc.
The original coding threw ERROR if replay failed to remove the directories,
but that is a serious overreaction. Throwing an error aborts recovery,
and worse means that manual intervention will be needed to get the database
to start again, since otherwise the same error will recur on subsequent
attempts to replay the same WAL record. And the consequence of failing to
remove the directories is only that some probably-small amount of disk
space is wasted, so it hardly seems justified to throw an error.
Accordingly, arrange to report such failures as LOG messages and keep going
when a failure occurs during replay.
Back-patch to 9.0 where Hot Standby was introduced. In principle such
problems can occur in earlier releases, but Hot Standby increases the odds
of trouble significantly. Given the lack of field reports of such issues,
I'm satisfied with patching back as far as the patch applies easily.
Originally, most of this code assumed that no Postgres backends could be
running concurrently with it, and so no locking could be needed. That
assumption fails in Hot Standby. While it's still true that Hot Standby
backends should never change values like nextXid, they can examine them,
and consistency is important in some cases such as when computing a
snapshot. Therefore, prudence requires that WAL replay code obtain the
relevant locks when modifying such variables, even though it can examine
them without taking a lock. We were following that coding rule in some
places but not all. This commit applies the coding rule uniformly to all
updates of ShmemVariableCache and MultiXactState fields; a search of the
replay routines did not find any other cases that seemed to be at risk.
In addition, this commit fixes a longstanding thinko in replay of NEXTOID
and checkpoint records: we tried to advance nextOid only if it was behind
the value in the WAL record, but the comparison would draw the wrong
conclusion if OID wraparound had occurred since the previous value.
Better to just unconditionally assign the new value, since OID assignment
shouldn't be happening during replay anyway.
The additional locking seems to be more in the nature of future-proofing
than fixing any live bug, so I am not going to back-patch it. The NEXTOID
fix will be back-patched separately.
RestoreBkpBlocks was in the habit of zeroing and refilling the target
buffer; which was perfectly safe when the code was written, but is unsafe
during Hot Standby operation. The reason is that we have coding rules
that allow backends to continue accessing a tuple in a heap relation while
holding only a pin on its buffer. Such a backend could see transiently
zeroed data, if WAL replay had occasion to change other data on the page.
This has been shown to be the cause of bug #6425 from Duncan Rance (who
deserves kudos for developing a sufficiently-reproducible test case) as
well as Bridget Frey's re-report of bug #6200. It most likely explains the
original report as well, though we don't yet have confirmation of that.
To fix, change the code so that only bytes that are supposed to change will
change, even transiently. This actually saves cycles in RestoreBkpBlocks,
since it's not writing the same bytes twice.
Also fix seq_redo, which has the same disease, though it has to work a bit
harder to meet the requirement.
So far as I can tell, no other WAL replay routines have this type of bug.
In particular, the index-related replay routines, which would certainly be
broken if they had to meet the same standard, are not at risk because we
do not have coding rules that allow access to an index page when not
holding a buffer lock on it.
Back-patch to 9.0 where Hot Standby was added.
All other WAL redo routines either call RestoreBkpBlocks() or Assert that
they haven't been passed any backup blocks. Make this one do likewise.
Also, fix incorrect routine name in its failure message.
When testing bits (but not when setting or clearing them), we now
won't check whether the map has been extended. This significantly
improves performance in the case where the visibility map doesn't
exist yet, by avoiding an extra system call per tuple. To make
sure backends notice eventually, send an smgr inval on VM extension.
Dean Rasheed, with minor modifications by me.
On some platforms, strtod() reports ERANGE for a denormalized value (ie,
one that can be represented as distinct from zero, but is too small to have
full precision). On others, it doesn't. It seems better to try to accept
these values consistently, so add a test to see if the result value
indicates a true out-of-range condition. This should be okay per Single
Unix Spec. On machines where the underlying math isn't IEEE standard, the
behavior for such small numbers may not be very consistent, but then it
wouldn't be anyway.
Marti Raudsepp, after a proposal by Jeroen Vermeulen
Like the XML data type, we simply store JSON data as text, after checking
that it is valid. More complex operations such as canonicalization and
comparison may come later, but this is enough for not.
There are a few open issues here, such as whether we should attempt to
detect UTF-8 surrogate pairs represented as \uXXXX\uYYYY, but this gets
the basic framework in place.
If there was a wait-until-free process in the head of the wait queue,
followed by an exclusive locker, the exclusive locker was not be woken up
as it should.
The sequence USAGE privilege is sufficiently similar to the SQL
standard that it seems reasonable to show in the information schema.
Also add some compatibility notes about it on the GRANT reference
page.
When a backend needs to flush the WAL, and someone else is already flushing
the WAL, wait until it releases the WALInsertLock and check if we still need
to do the flush or if the other backend already did the work for us, before
acquiring WALInsertLock. This helps group commit, because when the WAL flush
finishes, all the backends that were waiting for it can be woken up in one
go, and the can all concurrently observe that they're done, rather than
waking them up one by one in a cascading fashion.
This is based on a new LWLock function, LWLockWaitUntilFree(), which has
peculiar semantics. If the lock is immediately free, it grabs the lock and
returns true. If it's not free, it waits until it is released, but then
returns false without grabbing the lock. This is used in XLogFlush(), so
that when the lock is acquired, the backend flushes the WAL, but if it's
not, the backend first checks the current flush location before retrying.
Original patch and benchmarking by Peter Geoghegan and Simon Riggs, although
this patch as committed ended up being very different from that.
When default_text_search_config, default_tablespace, or temp_tablespaces
setting is set per-user or per-database, with an "ALTER USER/DATABASE SET
..." statement, don't throw an error if the text search configuration or
tablespace does not exist. In case of text search configuration, even if
it doesn't exist in the current database, it might exist in another
database, where the setting is intended to have its effect. This behavior
is now the same as search_path's.
Tablespaces are cluster-wide, so the same argument doesn't hold for
tablespaces, but there's a problem with pg_dumpall: it dumps "ALTER USER
SET ..." statements before the "CREATE TABLESPACE" statements. Arguably
that's pg_dumpall's fault - it should dump the statements in such an order
that the tablespace is created first and then the "ALTER USER SET
default_tablespace ..." statements after that - but it seems better to be
consistent with search_path and default_text_search_config anyway. Besides,
you could still create a dump that throws an error, by creating the
tablespace, running "ALTER USER SET default_tablespace", then dropping the
tablespace and running pg_dumpall on that.
Backpatch to all supported versions.
btcostestimate() makes an estimate of the number of index tuples that will
be visited based on knowledge of which index clauses can actually bound the
scan within nbtree. However, it forgot to account for partial indexes in
this calculation, with the result that the cost of the index scan could be
significantly overestimated for a partial index. Fix that by merging the
predicate with the abbreviated indexclause list, in the same way as we do
with the full list to estimate how many heap tuples will be visited.
Also, slightly increase the "fudge factor" that's meant to give preference
to smaller indexes over larger ones. While this is applied to all indexes,
it's most important for partial indexes since it can be the only factor
that makes a partial index look cheaper than a similar full index.
Experimentation shows that the existing value is so small as to easily get
swamped by noise such as page-boundary-roundoff behavior. I'm tempted to
kick it up more than this, but will refrain for now.
Per report from Ruben Blanco. These are long-standing issues, but given
the lack of prior complaints I'm not going to risk changing planner
behavior in back branches by back-patching.
In commit 57664ed25e, I made the planner
wrap non-simple-variable outputs of appendrel children (IOW, child SELECTs
of UNION ALL subqueries) inside PlaceHolderVars, in order to solve some
issues with EquivalenceClass processing. However, this means that any
upper-level WHERE clauses mentioning such outputs will now contain
PlaceHolderVars after they're pushed down into the appendrel child,
and that prevents indxpath.c from recognizing that they could be matched
to index expressions. To fix, add explicit stripping of PlaceHolderVars
from index operands, same as we have long done for RelabelType nodes.
Add a regression test covering both this and the plain-UNION case (which
is a totally different code path, but should also be able to do it).
Per bug #6416 from Matteo Beccati. Back-patch to 9.1, same as the
previous change.
Formerly we passed an empty list to each per-child-table invocation of
grouping_planner, and then merged the results into the global list.
However, that fails if there's a CTE attached to the statement, because
create_ctescan_plan uses the list to find the plan referenced by a CTE
reference; so it was unable to find any CTEs attached to the outer UPDATE
or DELETE. But there's no real reason not to use the same list throughout
the process, and doing so is simpler and faster anyway.
Per report from Josh Berkus of "could not find plan for CTE" failures.
Back-patch to 9.1 where we added support for WITH attached to UPDATE or
DELETE. Add some regression test cases, too.
We can't just skip initializing such subplans, because the referencing CTE
node will expect to find the subplan available when it initializes. That
in turn means that ExecInitModifyTable must allow the case (which actually
it needed to do anyway, since there's no guarantee that ModifyTable is
exactly at the top of the CTE plan tree). So move the complaint about not
being allowed in EvalPlanQual mode to execution instead of initialization.
Testing turned up yet another problem, which is that we'd try to
re-initialize the result relation's index list, leading to leaks and
dangling pointers.
Per report from Phil Sorber. Back-patch to 9.1 where data-modifying CTEs
were introduced.
After the planner was fixed to convert some IN/EXISTS subqueries into
semijoins or antijoins, we had to prevent it from doing that in some
cases where the plans risked getting much worse. The reason the plans
got worse was that in the unoptimized implementation, subqueries could
reference parameters from the outer query at any join level, and so
full table scans could be avoided even if they were one or more levels
of join below where the semi/anti join would be. Now that we have
sufficient mechanism in the planner to handle such cases properly,
it should no longer be necessary to play dumb here.
This reverts commits 07b9936a0f and
cd1f0d04bf. The latter was a stopgap
fix that wasn't really sufficiently analyzed at the time. Rather
than just restricting ourselves to cases where the new join can be
stacked on the right-hand input, we should also consider whether it
can be stacked on the left-hand input.
This patch fixes the planner so that it can generate nestloop-with-
inner-indexscan plans even with one or more levels of joining between
the indexscan and the nestloop join that is supplying the parameter.
The executor was fixed to handle such cases some time ago, but the
planner was not ready. This should improve our plans in many situations
where join ordering restrictions formerly forced complete table scans.
There is probably a fair amount of tuning work yet to be done, because
of various heuristics that have been added to limit the number of
parameterized paths considered. However, we are not going to find out
what needs to be adjusted until the code gets some real-world use, so
it's time to get it in there where it can be tested easily.
Note API change for index AM amcostestimate functions. I'm not aware of
any non-core index AMs, but if there are any, they will need minor
adjustments.
Hitherto, the information schema only showed explicitly granted
privileges that were visible in the *acl catalog columns. If no
privileges had been granted, the implicit privileges were not shown.
To fix that, add an SQL-accessible version of the acldefault()
function, and use that inside the aclexplode() calls to substitute the
catalog-specific default privilege set for null values.
reviewed by Abhijit Menon-Sen
In e5e2fc842c, blank lines were removed
after a comment block, which now looks as though the comment refers to
the immediately following code, but it actually refers to the
preceding code. So put the blank lines back.
This has been the behavior already in most cases, but through
omission, ALTER DOMAIN / OWNER TO and ALTER DOMAIN / SET SCHEMA would
silently work on non-domain types as well.
Those fields only appear in the structs so that genbki.pl can create
the BKI bootstrap files for the catalogs. But they are not actually
usable from C. So hiding them can prevent coding mistakes, saves
stack space, and can help the compiler.
In certain catalogs, the first variable-length field has been kept
visible after manual inspection. These exceptions are noted in C
comments.
reviewed by Tom Lane
Normally, accessing variable-length members of catalog structures past
the first one doesn't work at all. Here, it happened to work because
indnatts was checked to be 1, and so the defined FormData_pg_index
layout, using int2vector[1] and oidvector[1] for variable-length
arrays, happened to match the actual memory layout. But it's a very
fragile assumption, and it's not in a performance-critical path, so
code it properly using heap_getattr() instead.
bug analysis by Tom Lane
Our own qsort_arg() implementation doesn't have the defect previously
observed to affect only QNX 4, so it seems sufficiently to assert that
it isn't broken rather than retesting. Also, update a few comments to
clarify why it's valuable to retain a tie-break rule based on CTID
during index builds.
Peter Geoghegan, with slight tweaks by me.
We now use the same error message for ALTER TABLE .. ADD COLUMN or
ALTER TABLE .. RENAME COLUMN that we do for CREATE TABLE. The old
message was accurate, but might be confusing to users not aware of our
system columns.
Vik Reykja, with some changes by me, and further proofreading by Tom Lane
To make it wake up promptly when activity starts again, backends nudge it
by setting a latch in MarkBufferDirty(). The latch is kept set while
bgwriter is active, so there is very little overhead from that when the
system is busy. It is only armed before going into longer sleep.
Peter Geoghegan, with some changes by me.
This doesn't do anything useful just yet, but is intended as supporting
infrastructure for allowing sepgsql to sensibly check DROP permissions.
KaiGai Kohei and Robert Haas
Add counters for number and size of temporary files used
for spill-to-disk queries for each database to the
pg_stat_database view.
Tomas Vondra, review by Magnus Hagander
Rip out a regression test that doesn't play well with settings put in
place by the build farm, and rewrite the code in CheckIndexCompatible
in a hopefully more transparent style.
This gives up the "don't rewrite the index" behavior in a couple of
relatively unimportant cases, such as changing between an array type
and an unconstrained domain over that array type, in return for
making this code more future-proof.
Noah Misch
Base backup follows recommended procedure, plus goes to great
lengths to ensure that partial page writes are avoided.
Jun Ishizuka and Fujii Masao, with minor modifications
This reports the depth level of triggers currently in execution, or zero
if not called from inside a trigger.
No catversion bump in this patch, but you have to initdb if you want
access to the new function.
Author: Kevin Grittner
Replication occurs only to memory on standby, not to disk,
so provides additional performance if user wishes to
reduce durability level slightly. Adds concept of multiple
independent sync rep queues.
Fujii Masao and Simon Riggs
We log AccessExclusiveLocks for replay onto standby nodes,
but because of timing issues on ProcArray it is possible to
log a lock that is still held by a just committed transaction
that is very soon to be removed. To avoid any timing issue we
avoid applying locks made by transactions with InvalidXid.
Simon Riggs, bug report Tom Lane, diagnosis Pavan Deolasee
This separates the state (running/idle/idleintransaction etc) into
it's own field ("state"), and leaves the query field containing just
query text.
The query text will now mean "current query" when a query is running
and "last query" in other states. Accordingly,the field has been
renamed from current_query to query.
Since backwards compatibility was broken anyway to make that, the procpid
field has also been renamed to pid - along with the same field in
pg_stat_replication for consistency.
Scott Mead and Magnus Hagander, review work from Greg Smith
That avoids errors when the functions are used in queries like "SELECT
pg_relation_size(oid) FROM pg_class", and a table is dropped concurrently.
Phil Sorber
When the only remaining active transactions are READ ONLY, we do a "partial
cleanup" of committed transactions because certain types of conflicts
aren't possible anymore. For committed r/w transactions, we release the
SIREAD locks but keep the SERIALIZABLEXACT. However, for committed r/o
transactions, we can go further and release the SERIALIZABLEXACT too. The
problem was with the latter case: we were returning the SERIALIZABLEXACT to
the free list without removing it from the finished list.
The only real change in the patch is the SHMQueueDelete line, but I also
reworked some of the surrounding code to make it obvious that r/o and r/w
transactions are handled differently -- the existing code felt a bit too
clever.
Dan Ports
This prevents the postmaster from unexpectedly croaking if postgresql.conf
contains something like:
include 'invalid_directory_name'
Noah Misch. Reviewed by Tom Lane and myself.
When creating a child table, or when attaching an existing table as
child of another, we must not allow inheritable constraints to be
merged with non-inheritable ones, because then grandchildren would not
properly get the constraint. This would violate the grandparent's
expectations.
Bugs noted by Robert Haas.
Author: Nikhil Sontakke
In the previous coding, it was possible for a relation to be created
via CREATE TABLE, CREATE VIEW, CREATE SEQUENCE, CREATE FOREIGN TABLE,
etc. in a schema while that schema was meanwhile being concurrently
dropped. This led to a pg_class entry with an invalid relnamespace
value. The same problem could occur if a relation was moved using
ALTER .. SET SCHEMA while the target schema was being concurrently
dropped. This patch prevents both of those scenarios by locking the
schema to which the relation is being added using AccessShareLock,
which conflicts with the AccessExclusiveLock taken by DROP.
As a desirable side effect, this also prevents the use of CREATE OR
REPLACE VIEW to queue for an AccessExclusiveLock on a relation on which
you have no rights: that will now fail immediately with a permissions
error, before trying to obtain a lock.
We need similar protection for all other object types, but as everything
other than relations uses a slightly different set of code paths, I'm
leaving that for a separate commit.
Original complaint (as far as I could find) about CREATE by Nikhil
Sontakke; risk for ALTER .. SET SCHEMA pointed out by Tom Lane;
further details by Dan Farina; patch by me; review by Hitoshi Harada.
When the remote end of the pipe is closed, select() reports the fd as
readable, but poll() has a separate POLLHUP return code for that.
Spotted by Peter Geoghegan.
Allows a user to use pg_cancel_queries() to cancel queries in
other backends if they are running under the same role.
pg_terminate_backend() still requires superuser permissoins.
Short patch, many authors working on the bikeshed: Magnus Hagander,
Josh Kupershmidt, Edward Muller, Greg Smith.
superuser doesn't have doesn't make much sense, as a superuser can do
whatever he wants through other means, anyway. So instead of granting
replication privilege to superusers in CREATE USER time by default, allow
replication connection from superusers whether or not they have the
replication privilege.
Patch by Noah Misch, per discussion on bug report #6264
As noted by Tom Lane, the previous coding in this area, which I
introduced in commit bbb6e559c4, was
poorly tested and caused the vacuum's second heap to go into what would
have been an infinite loop but for the fact that it eventually caused a
memory allocation failure. This version seems to work better.
Previously we used ReadRecPtr rather than EndRecPtr, which was
not a serious error but caused pg_stat_replication to report
incorrect replay_location until at least one WAL record is replayed.
Fujii Masao
In commit 7b0d0e9356, I made CLUSTER and
VACUUM FULL try to preserve toast value OIDs from the original toast table
to the new one. However, if we have to copy both live and recently-dead
versions of a row that has a toasted column, those versions may well
reference the same toast value with the same OID. The patch then led to
duplicate-key failures as we tried to insert the toast value twice with the
same OID. (The previous behavior was not very desirable either, since it
would have silently inserted the same value twice with different OIDs.
That wastes space, but what's worse is that the toast values inserted for
already-dead heap rows would not be reclaimed by subsequent ordinary
VACUUMs, since they go into the new toast table marked live not deleted.)
To fix, check if the copied OID already exists in the new toast table, and
if so, assume that it stores the desired value. This is reasonably safe
since the only case where we will copy an OID from a previous toast pointer
is when toast_insert_or_update was given that toast pointer and so we just
pulled the data from the old table; if we got two different values that way
then we have big problems anyway. We do have to assume that no other
backend is inserting items into the new toast table concurrently, but
that's surely safe for CLUSTER and VACUUM FULL.
Per bug #6393 from Maxim Boguk. Back-patch to 9.0, same as the previous
patch.
constructed before acquiring WALInsertLock, which slightly reduces the time
the lock is held. Although I could not measure any benefit in benchmarks,
the code is more readable this way.
The original implementation of this interpreted it as a kind of
"inheritance" facility and named all the internal structures
accordingly. This turned out to be very confusing, because it has
nothing to do with the INHERITS feature. So rename all the internal
parser infrastructure, update the comments, adjust the error messages,
and split up the regression tests.
ALTER TABLE (and ALTER VIEW, ALTER SEQUENCE, etc.) now use a
RangeVarGetRelid callback to check permissions before acquiring a table
lock. We also now use the same callback for all forms of ALTER TABLE,
rather than having separate, almost-identical callbacks for ALTER TABLE
.. SET SCHEMA and ALTER TABLE .. RENAME, and no callback at all for
everything else.
I went ahead and changed the code so that no form of ALTER TABLE works
on foreign tables; you must use ALTER FOREIGN TABLE instead. In 9.1,
it was possible to use ALTER TABLE .. SET SCHEMA or ALTER TABLE ..
RENAME on a foreign table, but not any other form of ALTER TABLE, which
did not seem terribly useful or consistent.
Patch by me; review by Noah Misch.
Previously, this was hardcoded: we always had 8. Performance testing
shows that isn't enough, especially on big SMP systems, so we allow it
to scale up as high as 32 when there's adequate memory. On the flip
side, when shared_buffers is very small, drop the number of CLOG buffers
down to as little as 4, so that we can start the postmaster even
when very little shared memory is available.
Per extensive discussion with Simon Riggs, Tom Lane, and others on
pgsql-hackers.
As noted by Heikki Linnakangas, the previous coding confused the "flags"
variable with the "mask" variable. The affect of this appears to be that
unlogged buffers would get written out at every checkpoint rather than
only at shutdown time. Although that's arguably an acceptable failure
mode, I'm back-patching this change, since it seems like a poor idea to
rely on this happening to work.
ALTER DOMAIN / DROP CONSTRAINT on a nonexistent constraint name did
not report any error. Now it reports an error. The IF EXISTS option
was added to get the usual behavior of ignoring nonexistent objects to
drop.
As previously coded, the QueryDesc's dest pointer was left dangling
(pointing at an already-freed receiver object) after ExecutorEnd. It's a
bit astonishing that it took us this long to notice, and I'm not sure that
the known problem case with SQL functions is the only one. Fix it by
saving and restoring the original receiver pointer, which seems the most
bulletproof way of ensuring any related bugs are also covered.
Per bug #6379 from Paul Ramsey. Back-patch to 8.4 where the current
handling of SELECT INTO was introduced.
Because coerce_type recurses into the argument of a CollateExpr,
coerce_to_target_type's longstanding code for detecting whether coerce_type
had actually done anything (to wit, returned a different node than it
passed in) was broken in 9.1. This resulted in unexpected failures in
hide_coercion_node; which was not the latter's fault, since it's critical
that we never call it on anything that wasn't inserted by coerce_type.
(Else we might decide to "hide" a user-written function call.)
Fix by removing and replacing the CollateExpr in coerce_to_target_type
itself. This is all pretty ugly but I don't immediately see a way to make
it nicer.
Per report from Jean-Yves F. Barbier.
This reverts commit ff68b256a5.
The recent change to use -fexcess-precision=standard should make those
Asserts safe, and does fix a test case that formerly crashed for me,
so I think there's no need to have a cross-version difference in the
code here.
All supported platforms support the C89 standard function atexit()
(SunOS 4 probably being the last one not to), and supporting both
makes the code clumsy.
In commit e2c2c2e8b1 I made use of nested
list structures to show which clauses went with which index columns, but
on reflection that's a data structure that only an old-line Lisp hacker
could love. Worse, it adds unnecessary complication to the many places
that don't much care which clauses go with which index columns. Revert
to the previous arrangement of flat lists of clauses, and instead add a
parallel integer list of column numbers. The places that care about the
pairing can chase both lists with forboth(), while the places that don't
care just examine one list the same as before.
The only real downside to this is that there are now two more lists that
need to be passed to amcostestimate functions in case they care about
column matching (which btcostestimate does, so not passing the info is not
an option). Rather than deal with 11-argument amcostestimate functions,
pass just the IndexPath and expect the functions to extract fields from it.
That gets us down to 7 arguments which is better than 11, and it seems
more future-proof against likely additions to the information we keep
about an index path.
It's potentially useful for an index to repeat the same indexable column
or expression in multiple index columns, if the columns have different
opclasses. (If they share opclasses too, the duplicate column is pretty
useless, but nonetheless we've allowed such cases since 9.0.) However,
the planner failed to cope with this, because createplan.c was relying on
simple equal() matching to figure out which index column each index qual
is intended for. We do have that information available upstream in
indxpath.c, though, so the fix is to not flatten the multi-level indexquals
list when putting it into an IndexPath. Then we can rely on the sublist
structure to identify target index columns in createplan.c. There's a
similar issue for index ORDER BYs (the KNNGIST feature), so introduce a
multi-level-list representation for that too. This adds a bit more
representational overhead, but we might more or less buy that back by not
having to search for matching index columns anymore in createplan.c;
likewise btcostestimate saves some cycles.
Per bug #6351 from Christian Rudolph. Likely symptoms include the "btree
index keys must be ordered by attribute" failure shown there, as well as
"operator MMMM is not a member of opfamily NNNN".
Although this is a pre-existing problem that can be demonstrated in 9.0 and
9.1, I'm not going to back-patch it, because the API changes in the planner
seem likely to break things such as index plugins. The corner cases where
this matters seem too narrow to justify possibly breaking things in a minor
release.
When a view is marked as a security barrier, it will not be pulled up
into the containing query, and no quals will be pushed down into it,
so that no function or operator chosen by the user can be applied to
rows not exposed by the view. Views not configured with this
option cannot provide robust row-level security, but will perform far
better.
Patch by KaiGai Kohei; original problem report by Heikki Linnakangas
(in October 2009!). Review (in earlier versions) by Noah Misch and
others. Design advice by Tom Lane and myself. Further review and
cleanup by me.
You could already rename domains using ALTER TYPE, but with this new
command it is more consistent with how other commands treat domains as
a subcategory of types.
We forgot to modify column ACLs, so privileges were still shown as having
been granted by the old owner. This meant that neither the new owner nor
a superuser could revoke the now-untraceable-to-table-owner permissions.
Per bug #6350 from Marc Balmer.
This has been wrong since column ACLs were added, so back-patch to 8.4.
In the previous coding, a user could queue up for an AccessExclusiveLock
on a table they did not have permission to cluster, thus potentially
interfering with access by authorized users who got stuck waiting behind
the AccessExclusiveLock. This approach avoids that. cluster() has the
same permissions-checking requirements as REINDEX TABLE, so this commit
moves the now-shared callback to tablecmds.c and renames it, per
discussion with Noah Misch.
When a PORTAL_ONE_SELECT query is executed, we can opportunistically
reuse the parse/plan shot for the execution phase. This cuts down the
number of snapshots per simple query from 2 to 1 for the simple
protocol, and 3 to 2 for the extended protocol. Since we are only
reusing a snapshot taken early in the processing of the same protocol
message, the change shouldn't be user-visible, except that the remote
possibility of the planning and execution snapshots being different is
eliminated.
Note that this change does not make it safe to assume that the parse/plan
snapshot will certainly be reused; that will currently only happen if
PortalStart() decides to use the PORTAL_ONE_SELECT strategy. It might
be worth trying to provide some stronger guarantees here in the future,
but for now we don't.
Patch by me; review by Dimitri Fontaine.
The original coding of this function overlooked the possibility that
it could be passed anything except simple OpExpr indexquals. But
ScalarArrayOpExpr is possible too, and the code would probably crash
(and surely give ridiculous answers) in such a case. Add logic to try
to estimate sanely for such cases.
In passing, fix the treatment of inner-indexscan cost estimation: it was
failing to scale up properly for multiple iterations of a nestloop.
(I think somebody might've thought that index_pages_fetched() is linear,
but of course it's not.)
Report, diagnosis, and preliminary patch by Marti Raudsepp; I refactored
it a bit and fixed the cost estimation.
Back-patch into 9.1 where the bogus code was introduced.
smgrdounlink takes care to not throw an ERROR if it fails to unlink
something, but that caution was rendered useless by commit
3396000684, which put an smgrexists call in
front of it; smgrexists *does* throw error if anything looks funny, such
as getting a permissions error from trying to open the file. If that
happens post-commit, you get a PANIC, and what's worse the same logic
appears in the WAL replay code, so the database even fails to restart.
Restore the intended behavior by removing the smgrexists call --- it isn't
accomplishing anything that we can't do better by adjusting mdunlink's
ideas of whether it ought to warn about ENOENT or not.
Per report from Joseph Shraibman of unrecoverable crash after trying to
drop a table whose FSM fork had somehow gotten chmod'd to 000 permissions.
Backpatch to 8.4, where the bogus coding was introduced.
This adds support for the more or less SQL-conforming USAGE privilege
on types and domains. The intent is to be able restrict which users
can create dependencies on types, which restricts the way in which
owners can alter types.
reviewed by Yeb Havinga
On reflection, the original name seems way too generic for a global
symbol. A quick check shows this is the only exported function name
in SP-GiST that doesn't begin with "spg" or contain "SpGist", so the
rest of them seem all right.
This makes them enforceable only on the parent table, not on children
tables. This is useful in various situations, per discussion involving
people bitten by the restrictive behavior introduced in 8.4.
Message-Id:
8762mp93iw.fsf@comcast.netCAFaPBrSMMpubkGf4zcRL_YL-AERUbYF_-ZNNYfb3CVwwEqc9TQ@mail.gmail.com
Authors: Nikhil Sontakke, Alex Hunsaker
Reviewed by Robert Haas and myself
Operator classes can specify whether or not they support this; this
preserves the flexibility to use lossy representations within an index.
In passing, move constant data about a given index into the rd_amcache
cache area, instead of doing fresh lookups each time we start an index
operation. This is mainly to try to make sure that spgcanreturn() has
insignificant cost; I still don't have any proof that it matters for
actual index accesses. Also, get rid of useless copying of FmgrInfo
pointers; we can perfectly well use the relcache's versions in-place.
The need for this was debated when we put in the index-only-scan feature,
but at the time we had no near-term expectation of having AMs that could
support such scans for only some indexes; so we kept it simple. However,
the SP-GiST AM forces the issue, so let's fix it.
This patch only installs the new API; no behavior actually changes.
SP-GiST is comparable to GiST in flexibility, but supports non-balanced
partitioned search structures rather than balanced trees. As described at
PGCon 2011, this new indexing structure can beat GiST in both index build
time and query speed for search problems that it is well matched to.
There are a number of areas that could still use improvement, but at this
point the code seems committable.
Teodor Sigaev and Oleg Bartunov, with considerable revisions by Tom Lane
Heikki Linnakangas had the idea of rearranging GetSnapshotData to
avoid checking for sub-XIDs when no top-level XID is present. This
patch does that plus further a bit of further, related rearrangement.
Benchmarking show a significant improvement on unlogged tables at
higher concurrency levels, and mostly indifferent result on permanent
tables (which are presumably bottlenecked elsewhere). Most of the
benefit seems to come from using the new NormalTransactionIdPrecedes()
macro rather than the function call TransactionIdPrecedes().
This works the same as include, except that an error is not thrown
if the file is missing. Instead the fact that it's missing is
logged.
Greg Smith, reviewed by Euler Taveira de Oliveira.
If the referrent of a name changes while we're waiting for the lock,
we must recheck permissons. We also now check the relkind before
locking, since it's easy to do that long the way.
Patch by me; review by Noah Misch.
Previously, renaming a table, sequence, view, index, foreign table,
column, or trigger checked permissions before locking the object, which
meant that if permissions were revoked during the lock wait, we would
still allow the operation. Similarly, if the original object is dropped
and a new one with the same name is created, the operation will be allowed
if we had permissions on the old object; the permissions on the new
object don't matter. All this is now fixed.
Along the way, attempting to rename a trigger on a foreign table now gives
the same error message as trying to create one there in the first place
(i.e. that it's not a table or view) rather than simply stating that no
trigger by that name exists.
Patch by me; review by Noah Misch.
Removing this bit from xl_info allows us to restore the old limit of four
(not three) separate pages touched by a WAL record, which is needed for the
upcoming SP-GiST feature, and will likely be useful elsewhere in future.
When we implemented XLR_BKP_REMOVABLE in 2007, we had to do it like that
because no special WAL-visible action was taken when starting a backup.
However, now we force a segment switch when starting a backup, so a
compressing WAL archiver (such as pglesslog) that uses the state shown in
the current page header will not be fooled as to removability of backup
blocks. The only downside is that the archiver will not return to
compressing mode for up to one WAL page after the backup is over, which is
a small price to pay for getting back the extra xl_info bit. In any case
the archiver could look for XLOG_BACKUP_END records if it thought it was
worth the trouble to do so.
Bump XLOG_PAGE_MAGIC since this is effectively a change in WAL format.
I forgot to change the functions to use the PG_GETARG_INET_PP() macro,
when I changed DatumGetInetP() to unpack the datum, like Datum*P macros
usually do. Also, I screwed up the definition of the PG_GETARG_INET_PP()
macro, and didn't notice because it wasn't used.
This fixes the memory leak when sorting inet values, as reported
by Jochen Erwied and debugged by Andres Freund. Backpatch to 8.3, like
the previous patch that broke it.
we don't reach consistency before replaying all of the WAL. Rename the
variable to reachedConsistency, to make its intention clearer.
In master, that was an active bug because of the recent patch to
immediately PANIC if a reference to a missing page is found in WAL after
reaching consistency, as Tom Lane's test case demonstrated. In 9.1 and 9.0,
the only consequence was a misleading "consistent recovery state reached at
%X/%X" message in the log at the beginning of crash recovery (the database
is not consistent at that point yet). In 8.4, the log message was not
printed in crash recovery, even though there was a similar
reachedMinRecoveryPoint local variable that was also set early. So,
backpatch to 9.1 and 9.0.
lost. The only way we detect that at the moment is when write() fails when
we try to write to the socket.
Florian Pflug with small changes by me, reviewed by Greg Jaskiewicz.
Make sure all calls are protected by HAVE_READLINK, and get the buffer
overflow tests right. Be a bit more paranoid about string length in
_tarWriteHeader(), too.
We don't have any such platforms now, but might in the future.
Also, detect cases when a tablespace symlink points to a path that
is longer than we can handle, and give a warning.
Instead, add a function pg_tablespace_location(oid) used to return
the same information, and do this by reading the symbolic link.
Doing it this way makes it possible to relocate a tablespace when the
database is down by simply changing the symbolic link.
This patch creates an API whereby a btree index opclass can optionally
provide non-SQL-callable support functions for sorting. In the initial
patch, we only use this to provide a directly-callable comparator function,
which can be invoked with a bit less overhead than the traditional
SQL-callable comparator. While that should be of value in itself, the real
reason for doing this is to provide a datatype-extensible framework for
more aggressive optimizations, as in Peter Geoghegan's recent work.
Robert Haas and Tom Lane
While logically correct, these two Asserts could fail depending on the
vagaries of floating-point arithmetic. In particular, on machines with
floating-point registers wider than standard "double" values, it was
possible for the compiler to compare a rounded-to-double value already
stored in memory with an unrounded long double value still in a register.
Given the preceding checks, these assertions aren't adding much, so let's
just get rid of them rather than try to find a compiler-proof fix.
Per report from Pavel Stehule.
Given the lack of previous complaints, and the fact that only developers
would be likely to trip over it, I'm only going to change this in HEAD,
even though the code has been like this for a long time.
invalid-page hash table, PANIC immediately. Immediate PANIC is much better
than waiting for end-of-recovery, which is what we did before, because the
end-of-recovery might not come until months later if this is a standby
server.
Also refrain from creating a restartpoint if there are invalid-page entries
in the hash table. Restarting recovery from such a restartpoint would not
see the invalid references, and wouldn't be able to cross-check them when
consistency is reached. That wouldn't matter when things are going smoothly,
but the more sanity checks you have the better.
Fujii Masao
Since record[] uses array_in, it needs to have its element type passed
as typioparam. In HEAD and 9.1, this fix essentially reverts commit
9bc933b212, which was a hack that is no
longer needed since domains don't set their typelem anymore. Before
that, adjust the logic so that only domains are excluded from being
treated like arrays, rather than assuming that only base types should
be included. Add a regression test to demonstrate the need for this.
Per report from Maxim Boguk.
Back-patch to 8.4, where type record[] was added.
In the previous coding, callers were faced with an awkward choice:
look up the name, do permissions checks, and then lock the table; or
look up the name, lock the table, and then do permissions checks.
The first choice was wrong because the results of the name lookup
and permissions checks might be out-of-date by the time the table
lock was acquired, while the second allowed a user with no privileges
to interfere with access to a table by users who do have privileges
(e.g. if a malicious backend queues up for an AccessExclusiveLock on
a table on which AccessShareLock is already held, further attempts
to access the table will be blocked until the AccessExclusiveLock
is obtained and the malicious backend's transaction rolls back).
To fix, allow callers of RangeVarGetRelid() to pass a callback which
gets executed after performing the name lookup but before acquiring
the relation lock. If the name lookup is retried (because
invalidation messages are received), the callback will be re-executed
as well, so we get the best of both worlds. RangeVarGetRelid() is
renamed to RangeVarGetRelidExtended(); callers not wishing to supply
a callback can continue to invoke it as RangeVarGetRelid(), which is
now a macro. Since the only one caller that uses nowait = true now
passes a callback anyway, the RangeVarGetRelid() macro defaults nowait
as well. The callback can also be used for supplemental locking - for
example, REINDEX INDEX needs to acquire the table lock before the index
lock to reduce deadlock possibilities.
There's a lot more work to be done here to fix all the cases where this
can be a problem, but this commit provides the general infrastructure
and fixes the following specific cases: REINDEX INDEX, REINDEX TABLE,
LOCK TABLE, and and DROP TABLE/INDEX/SEQUENCE/VIEW/FOREIGN TABLE.
Per discussion with Noah Misch and Alvaro Herrera.
On a platform that isn't supplying __FILE__, previous coding would either
crash or give a stale result for the filename string. Not sure how likely
that is, but the original code catered for it, so let's keep doing so.
In vpath builds, the __FILE__ macro that is used in verbose error
reports contains the full absolute file name, which makes the error
messages excessively verbose. So keep only the base name, thus
matching the behavior of non-vpath builds.
Force the transaction isolation level to READ COMMITTED in autovacuum
worker and launcher processes. There is no benefit to using a higher
isolation level, and doing so could result in delaying foreground
transactions (or maybe even causing unnecessary serialization failures?).
Noted by Dan Ports.
Also, make sure we disable zero_damaged_pages and statement_timeout in
the autovac launcher, not only workers. Now that the launcher can run
transactions, these settings could affect its behavior, and it seems
like the same arguments apply to the launcher as the workers.
This should make it easier to identify which row is problematic when an
insert or update is processing many rows.
The formatting is similar to that for unique-index violation messages,
except that we limit field widths to 64 bytes since otherwise the message
could get unreasonably long. (In particular, there's currently no attempt
to quote or escape field values that contain commas etc.)
Jan Kundrát, reviewed by Royce Ausburn, somewhat rewritten by me.
Moving the code two full tab stops to the right requires rethinking of
cosmetic code layout choices, which pgindent isn't really able to do for
us. Whitespace and comment adjustments only, no code changes.
While the deletion in itself wouldn't break things, any further creation
of objects in the script would result in dangling pg_depend entries being
added by recordDependencyOnCurrentExtension(). An example from Phil
Sorber convinced me that this is just barely likely enough to be worth
expending a couple lines of code to defend against. The resulting error
message might be confusing, but it's better than leaving corrupted catalog
contents for the user to deal with.
This function has now grown enough cases that a switch seems appropriate.
This results in a measurable speed improvement on some platforms, and
should certainly not hurt. The code's in need of a pgindent run now,
though.
Andres Freund
The EvalPlanQual machinery assumes that whole-row Vars generated for the
outputs of non-table RTEs will be of composite types. However, for the
case where the RTE is a function call returning a scalar type, we were
doing the wrong thing, as a result of sharing code with a parser case
where the function's scalar output is wanted. (Or at least, that's what
that case has done historically; it does seem a bit inconsistent.)
To fix, extend makeWholeRowVar's API so that it can support both use-cases.
This fixes Belinda Cussen's report of crashes during concurrent execution
of UPDATEs involving joins to the result of UNNEST() --- in READ COMMITTED
mode, we'd run the EvalPlanQual machinery after a conflicting row update
commits, and it was expecting to get a HeapTuple not a scalar datum from
the "wholerowN" variable referencing the function RTE.
Back-patch to 9.0 where the current EvalPlanQual implementation appeared.
In 9.1 and up, this patch also fixes failure to attach the correct
collation to the Var generated for a scalar-result case. An example:
regression=# select upper(x.*) from textcat('ab', 'cd') x;
ERROR: could not determine which collation to use for upper() function
Use of a randomly chosen large value was never exactly graceful, and
now that there are penalty functions that are intentionally using infinity,
it doesn't seem like a good idea for null-vs-not-null to be using something
less.
In the original implementation, a range-contained-by search had to scan
the entire index because an empty range could be lurking anywhere.
Improve that by adding a flag to upper GiST entries that says whether the
represented subtree contains any empty ranges.
Also, make a simple mod to the penalty function to discourage empty ranges
from getting pushed into subtrees without any. This needs more work, and
the picksplit function should be taught about it too, but that code can be
improved without causing an on-disk compatibility break; so we'll leave it
for another day.
Since we're breaking on-disk compatibility of range values anyway, I took
the opportunity to reorganize the range flags bits; the unused
RANGE_xB_NULL bits are now adjacent, which might open the door for using
them in some other way later.
In passing, remove the GiST range opclass entry for <>, which doesn't seem
like it can really be indexed usefully.
Alexander Korotkov, with some editorializing by Tom
In the cases where the result of the called proc is negated, we should
explicitly test both inputs for empty, to ensure we'll never return "true"
for an unsatisfiable query. In other cases we can rely on the called proc
to say the right thing.
This adds some I/O stats to the logging of autovacuum (when the
operation takes long enough that log_autovacuum_min_duration causes it
to be logged), so that it is easier to tune. Notably, it adds buffer
I/O counts (hits, misses, dirtied) and read and write rate.
Authors: Greg Smith and Noah Misch
A simple thinko in ginRedoUpdateMetapage, namely failing to increment a
loop counter, led to inserting records into the last pending-list page in
the wrong order (the opposite of that intended). So far as I can tell,
this would not upset the code that eventually flushes pending items into
the main part of the GIN index. But it did break the code that searched
the pending list for matches, resulting in transient failure to find
matching entries during index lookups, as illustrated in bug #6307 from
Maksym Boguk.
Back-patch to 8.4 where the incorrect code was introduced.
This speeds up snapshot-taking and reduces ProcArrayLock contention.
Also, the PGPROC (and PGXACT) structures used by two-phase commit are
now allocated as part of the main array, rather than in a separate
array, and we keep ProcArray sorted in pointer order. These changes
are intended to minimize the number of cache lines that must be pulled
in to take a snapshot, and testing shows a substantial increase in
performance on both read and write workloads at high concurrencies.
Pavan Deolasee, Heikki Linnakangas, Robert Haas
The WITH [NO] DATA option was not supported, nor the ability to specify
replacement column names; the former limitation wasn't even documented, as
per recent complaint from Naoya Anzai. Fix by moving the responsibility
for supporting these options into the executor. It actually takes less
code this way ...
catversion bump due to change in representation of IntoClause, which might
affect stored rules.
The original coding would not work for discrete ranges in which the
canonicalization rule is to produce symmetric boundaries (either [] or ()
style), as noted by Jeff Davis. Florian Pflug pointed out that we could
fix that by invoking the canonicalization function to see if the range
"between" the two given ranges normalizes to empty. This implementation
of Florian's idea is a tad slower than the original code, but only in the
case where there actually is a canonicalization function --- if not, it's
essentially the same logic as before.
Since range types can be created by non-superusers, we need to consider
their permissions. Ideally we'd check this when the type is used, not
when it's created, but that seems like much more trouble than it's worth.
The existing restriction that the support functions be immutable already
prevents most cases where an unauthorized call to a function might be
thought a security issue, and the fact that the user has no access to
the results of the system's calls to subtype_diff closes off the other
plausible reason for concern. So this check is basically pro-forma,
but let's make it anyway.
It's not clear that a per-datatype typanalyze function would be any more
useful than a generic typanalyze for ranges. What *is* clear is that
letting unprivileged users select typanalyze functions is a crash risk or
worse. So remove the option from CREATE TYPE AS RANGE, and instead put in
a generic typanalyze function for ranges. The generic function does
nothing as yet, but hopefully we'll improve that before 9.2 release.
Per discussion, the zero-argument forms aren't really worth the catalog
space (just write 'empty' instead). The one-argument forms have some use,
but they also have a serious problem with looking too much like functional
cast notation; to the point where in many real use-cases, the parser would
misinterpret what was wanted.
Committing this as a separate patch, with the thought that we might want
to revert part or all of it if we can think of some way around the cast
ambiguity.
Implement these tests directly instead of constructing a singleton range
and then applying range-contains. This saves a range serialize/deserialize
cycle as well as a couple of redundant bound-comparison steps, and adds
very little code on net.
Remove elem_contained_by_range from the GiST opclass: it doesn't belong
there because there is no way to use it in an index clause (where the
indexed column would have to be on the left). Its commutator is in the
opclass, and that's what counts.
In the normal course of events, this matters only if ALTER DEFAULT
PRIVILEGES has been used to revoke default INSERT permission. Whether
or not the new behavior is more or less likely to be what the user wants
when dealing only with the built-in privilege facilities is arguable,
but it's clearly better when using a loadable module such as sepgsql
that may use the hook in ExecCheckRTPerms to enforce additional
permissions checks.
KaiGai Kohei, reviewed by Albe Laurenz
Per discussion, relax the range input/construction rules so that the
only hard error is lower bound > upper bound. Cases where the lower
bound is <= upper bound, but the range nonetheless normalizes to empty,
are now permitted.
Fix core dump in range_adjacent when bounds are infinite. Marginal
cleanup of regression test cases, some more code commenting.
Fix up some infelicitous coding in DefineRange, and add some missing error
checks. Rearrange operator strategy number assignments for GiST anyrange
opclass so that they don't make such a mess of opr_sanity's table of
operator names associated with different strategy numbers. Assign
hopefully-temporary selectivity estimators to range operators that didn't
have one --- poor as the estimates are, they're still a lot better than the
default 0.5 estimate, and they'll shut up the opr_sanity test that wants to
see selectivity estimators on all built-in operators.
When the system is idle for awhile after activity, the "smoothed_alloc"
state variable in BgBufferSync converges slowly to zero. With standard
IEEE float arithmetic this results in several iterations with denormalized
values, which causes kernel traps and annoying log messages on some
poorly-designed platforms. There's no real need to track such small values
of smoothed_alloc, so we can prevent the kernel traps by forcing it to zero
as soon as it's too small to be interesting for our purposes. This issue
is purely cosmetic, since the iterations don't happen fast enough for the
kernel traps to pose any meaningful performance problem, but still it seems
worth shutting up the log messages.
The kernel log messages were previously reported by a number of people,
but kudos to Greg Matthews for tracking down exactly where they were coming
from.
When wal_level = 'hot_standby' we touched the last page of the
relation during a VACUUM, even if nothing else had happened.
That would alter the LSN of the last block and set the mtime
of the relation file unnecessarily. Noted by Thom Brown.
This gets rid of an impressive amount of duplicative code, with only
minimal behavior changes. DROP FOREIGN DATA WRAPPER now requires object
ownership rather than superuser privileges, matching the documentation
we already have. We also eliminate the historical warning about dropping
a built-in function as unuseful. All operations are now performed in the
same order for all object types handled by dropcmds.c.
KaiGai Kohei, with minor revisions by me
For a very long time, one of the parser's heuristics for resolving
ambiguous operator calls has been to assume that unknown-type literals are
of the same type as the other input (if it's known). However, this was
only used in the first step of quickly checking for an exact-types match,
and thus did not help in resolving matches that require coercion, such as
matches to polymorphic operators. As we add more polymorphic operators,
this becomes more of a problem. This patch adds another use of the same
heuristic as a last-ditch check before failing to resolve an ambiguous
operator or function call. In particular this will let us define the range
inclusion operator in a less limited way (to come in a follow-on patch).
A very long time ago, language names were specified as literals rather
than identifiers, so this code was added to do case-folding. But that
style has ben deprecated for many years so this isn't needed any more.
Language names will still be downcased when specified as unquoted
identifiers, but quoted identifiers or the old style using string
literals will be left as-is.
This gives a much better error message when the object of interest is
concurrently dropped and avoids needlessly failing when the object of
interest is concurrently dropped and recreated. It also improves the
behavior of two concurrent DROP IF EXISTS operations targeted at the
same object; as before, one will drop the object, but now the other
will emit the usual NOTICE indicating that the object does not exist,
instead of rolling back. As a fringe benefit, it's also slightly
less code.
Move the responsibility for caching specialized information about range
types into the type cache, so that the catalog lookups only have to occur
once per session. Rearrange APIs a bit so that fn_extra caching is
actually effective in the GiST support code. (Use of OidFunctionCallN is
bad enough for performance in itself, but it also prevents the function
from exploiting fn_extra caching.)
The range I/O functions are still not very bright about caching repeated
lookups, but that seems like material for a separate patch.
Also, avoid unnecessary use of memcpy to fetch/store the range type OID and
flags, and don't use the full range_deserialize machinery when all we need
to see is the flags value.
Also fix API error in range_gist_penalty --- it was failing to set *penalty
for any case involving an empty range.
A range type whose element type has 'd' alignment must have 'd' alignment
itself, else there is no guarantee that the element value can be used
in-place. (Because range_deserialize uses att_align_pointer which forcibly
aligns the given pointer, violations of this rule did not lead to SIGBUS
but rather to garbage data being extracted, as in one of the added
regression test cases.)
Also, you can't put a toast pointer inside a range datum, since the
referenced value could disappear with the range datum still present.
For consistency with the handling of arrays and records, I also forced
decompression of in-line-compressed bound values. It would work to store
them as-is, but our policy is to avoid situations that might result in
double compression.
Add assorted regression tests for this, and bump catversion because of
fixes to built-in pg_type entries.
Also some marginal cleanup of inconsistent/unnecessary error checks.
Change range_lower and range_upper to return NULL rather than throwing an
error when the input range is empty or the relevant bound is infinite. Per
discussion, throwing an error seems likely to be unduly hard to work with.
Also, this is more consistent with the behavior of the constructors, which
treat NULL as meaning an infinite bound.
Change range_before, range_after, range_adjacent to return false rather
than throwing an error when one or both input ranges are empty.
The original definition is unnecessarily difficult to use, and also can
result in undesirable planner failures since the planner could try to
compare an empty range to something else while deriving statistical
estimates. (This was, in fact, the cause of repeatable regression test
failures on buildfarm member jaguar, as well as intermittent failures
elsewhere.)
Also tweak rangetypes regression test to not drop all the objects it
creates, so that the final state of the regression database contains
some rangetype objects for pg_dump testing.
No functional changes in this commit (except I could not resist the
temptation to re-word a couple of error messages). This is just manual
cleanup after pgindent to make the code look reasonably like other PG
code, in preparation for more detailed code review to come.
Previously we waited for wal_writer_delay before flushing WAL. Now
we also wake WALWriter as soon as a WAL buffer page has filled.
Significant effect observed on performance of asynchronous commits
by Robert Haas, attributed to the ability to set hint bits on tuples
earlier and so reducing contention caused by clog lookups.
If it turns out we've locked the wrong OID, release the old lock. In
most cases, it's pretty harmless to retain the extra lock, but this
seems tidier and avoids using lock table slots unnecessarily.
Per discussion with Tom Lane.
This reverts commit 0180bd6180.
contrib/userlock is gone, but user-level locking still exists,
and is exposed via the pg_advisory* family of functions.
Heikki Linnakangas
Tom Lane
Robert Haas
Magnus Hagander
Peter Eisentraut
Alvaro Herrera
Andrew Dunstan
Simon Riggs
Bruce Momjian