Tom Lane [Sat, 1 Sep 2012 04:40:15 +0000 (00:40 -0400)]
More documentation updates for LATERAL.
Extend xfunc.sgml's discussion of set-returning functions to show an
example of using LATERAL, and recommend that over putting SRFs in the
targetlist.
In passing, reword func.sgml's section on set-returning functions so
that it doesn't claim that the functions listed therein are all the
built-in set-returning functions. That hasn't been true for a long
time, and trying to make it so doesn't seem like it would be an
improvement. (Perhaps we should rename that section?)
Only warn when connecting to a newer server, since connecting to older
servers works pretty well nowadays. Also update the documentation a
little about current psql/server compatibility expectations.
Andrew Dunstan [Sat, 1 Sep 2012 00:38:37 +0000 (20:38 -0400)]
Restore setting of _USE_32BIT_TIME_T to 32 bit MSVC builds.
This was removed in commit cd004067742ee16ee63e55abfb4acbd5f09fbaab,
we're not quite sure why, but there have been reports of crashes due
to AS Perl being built with it when we are not, and it certainly
seems like the right thing to do. There is still some uncertainty
as to why it sometimes fails and sometimes doesn't.
Original patch from Owais Khani, substantially reworked and
extended by Andrew Dunstan.
Tom Lane [Fri, 31 Aug 2012 22:57:12 +0000 (18:57 -0400)]
Partially restore qual scope checks in distribute_qual_to_rels().
The LATERAL implementation is now basically complete, and I still don't
see a cost-effective way to make an exact qual scope cross-check in the
presence of LATERAL. However, I did add a PlannerInfo.hasLateralRTEs flag
along the way, so it's easy to make the check only when not hasLateralRTEs.
That seems to still be useful, and it beats having no check at all.
Tom Lane [Fri, 31 Aug 2012 18:17:56 +0000 (14:17 -0400)]
Make configure probe for mbstowcs_l as well as wcstombs_l.
We previously supposed that any given platform would supply both or neither
of these functions, so that one configure test would be sufficient. It now
appears that at least on AIX this is not the case ... which is likely an
AIX bug, but nonetheless we need to cope with it. So use separate tests.
Per bug #6758; thanks to Andrew Hastie for doing the followup testing
needed to confirm what was happening.
Backpatch to 9.1, where we began using these functions.
Tom Lane [Fri, 31 Aug 2012 02:52:43 +0000 (22:52 -0400)]
Improve coding of gistchoose and gistRelocateBuildBuffersOnSplit.
This is mostly cosmetic, but it does eliminate a speculative portability
issue. The previous coding ignored the fact that sum_grow could easily
overflow (in fact, it could be summing multiple IEEE float infinities).
On a platform where that didn't guarantee to produce a positive result,
the code would misbehave. In any case, it was less than readable.
Alvaro Herrera [Thu, 30 Aug 2012 20:15:44 +0000 (16:15 -0400)]
Split tuple struct defs from htup.h to htup_details.h
This reduces unnecessary exposure of other headers through htup.h, which
is very widely included by many files.
I have chosen to move the function prototypes to the new file as well,
because that means htup.h no longer needs to include tupdesc.h. In
itself this doesn't have much effect in indirect inclusion of tupdesc.h
throughout the tree, because it's also required by execnodes.h; but it's
something to explore in the future, and it seemed best to do the htup.h
change now while I'm busy with it.
Tom Lane [Thu, 30 Aug 2012 18:32:22 +0000 (14:32 -0400)]
Suppress creation of backwardly-indexed paths for LATERAL join clauses.
Given a query such as
SELECT * FROM foo JOIN LATERAL (SELECT foo.var1) ss(x) ON ss.x = foo.var2
the existence of the join clause "ss.x = foo.var2" encourages indxpath.c to
build a parameterized path for foo using any index available for foo.var2.
This is completely useless activity, though, since foo has got to be on the
outside not the inside of any nestloop join with ss. It's reasonably
inexpensive to add tests that prevent creation of such paths, so let's do
that.
Robert Haas [Thu, 30 Aug 2012 18:14:22 +0000 (14:14 -0400)]
Document how to prevent PostgreSQL itself from exhausting memory.
The existing documentation in Linux Memory Overcommit seemed to
assume that PostgreSQL itself could never be the problem, or at
least it didn't tell you what to do about it.
Per discussion with Craig Ringer and Kevin Grittner.
Robert Haas [Thu, 30 Aug 2012 17:05:45 +0000 (13:05 -0400)]
Fix logic bug in gistchoose and gistRelocateBuildBuffersOnSplit.
Every time the best-tuple-found-so-far changes, we need to reset all
the penalty values in which_grow[] to the penalties for the new best
tuple. The old code failed to do this, resulting in inferior index
quality.
The original patch from Alexander Korotkov was just two lines; I took
the liberty of fleshing that out by adding a bunch of comments that I
hope will make this logic easier for others to understand than it was
for me.
Tom Lane [Thu, 30 Aug 2012 16:56:50 +0000 (12:56 -0400)]
Improve EXPLAIN's ability to cope with LATERAL references in plans.
push_child_plan/pop_child_plan didn't bother to adjust the "ancestors"
list of parent plan nodes when descending to a child plan node. I think
this was okay when it was written, but it's not okay in the presence of
LATERAL references, since a subplan node could easily be returning a
LATERAL value back up to the same nestloop node that provides the value.
Per changed regression test results, the omission led to failure to
interpret Param nodes that have perfectly good interpretations.
Peter Eisentraut [Thu, 30 Aug 2012 02:44:59 +0000 (22:44 -0400)]
Also check for Python platform-specific include directory
Python can be built to have two separate include directories: one for
platform-independent files and one for platform-specific files. So
far, this has apparently never mattered for a PL/Python build. But
with the new multi-arch Python packages in Debian and Ubuntu, this is
becoming the standard configuration on these platforms, so we must
check these directories separately to be able to build there.
Also add a bit of reporting in configure to be able to see better what
is going on with this.
Tom Lane [Thu, 30 Aug 2012 02:05:27 +0000 (22:05 -0400)]
Adjust definition of cheapest_total_path to work better with LATERAL.
In the initial cut at LATERAL, I kept the rule that cheapest_total_path
was always unparameterized, which meant it had to be NULL if the relation
has no unparameterized paths. It turns out to work much more nicely if
we always have *some* path nominated as cheapest-total for each relation.
In particular, let's still say it's the cheapest unparameterized path if
there is one; if not, take the cheapest-total-cost path among those of
the minimum available parameterization. (The first rule is actually
a special case of the second.)
This allows reversion of some temporary lobotomizations I'd put in place.
In particular, the planner can now consider hash and merge joins for
joins below a parameter-supplying nestloop, even if there aren't any
unparameterized paths available. This should bring planning of
LATERAL-containing queries to the same level as queries not using that
feature.
Along the way, simplify management of parameterized paths in add_path()
and friends. In the original coding for parameterized paths in 9.2,
I tried to minimize the logic changes in add_path(), so it just treated
parameterization as yet another dimension of comparison for paths.
We later made it ignore pathkeys (sort ordering) of parameterized paths,
on the grounds that ordering isn't a useful property for the path on the
inside of a nestloop, so we might as well get rid of useless parameterized
paths as quickly as possible. But we didn't take that reasoning as far as
we should have. Startup cost isn't a useful property inside a nestloop
either, so add_path() ought to discount startup cost of parameterized paths
as well. Having done that, the secondary sorting I'd implemented (in
add_parameterized_path) is no longer needed --- any parameterized path that
survives add_path() at all is worth considering at higher levels. So this
should be a bit faster as well as simpler.
This includes two micro-optimizations to the tight inner loop in descending
the SP-GiST tree: 1. avoid an extra function call to index_getprocinfo when
calling user-defined choose function, and 2. avoid a useless palloc+pfree
when node labels are not used.
Alvaro Herrera [Tue, 28 Aug 2012 23:02:00 +0000 (19:02 -0400)]
Split heapam_xlog.h from heapam.h
The heapam XLog functions are used by other modules, not all of which
are interested in the rest of the heapam API. With this, we let them
get just the XLog stuff in which they are interested and not pollute
them with unrelated includes.
Also, since heapam.h no longer requires xlog.h, many files that do
include heapam.h no longer get xlog.h automatically, including a few
headers. This is useful because heapam.h is getting pulled in by
execnodes.h, which is in turn included by a lot of files.
Tom Lane [Tue, 28 Aug 2012 00:17:12 +0000 (20:17 -0400)]
Add section IDs to subsections of syntax.sgml that lacked them.
This is so that these sections will have stable HTML tags that one can
link to, rather than things like "AEN1902". Perhaps we should mount a
campaign to do this everywhere, but I've found myself pointing at
syntax.sgml subsections often enough to be sure it's useful here.
Alvaro Herrera [Mon, 27 Aug 2012 18:21:09 +0000 (14:21 -0400)]
pg_upgrade: Fix exec_prog API to be less flaky
The previous signature made it very easy to pass something other than
the printf-format specifier in the corresponding position, without any
warning from the compiler.
While at it, move some of the escaping, redirecting and quoting
responsibilities from the callers into exec_prog() itself. This makes
the callsites cleaner.
Tom Lane [Mon, 27 Aug 2012 16:45:43 +0000 (12:45 -0400)]
Fix DROP INDEX CONCURRENTLY IF EXISTS.
This threw ERROR, not the expected NOTICE, if the index didn't exist.
The bug was actually visible in not-as-expected regression test output,
so somebody wasn't paying too close attention in commit 8cb53654dbdb4c386369eb988062d0bbb6de725e.
Per report from Brendan Byrd.
Collect and use histograms of lower and upper bounds for range types.
This enables selectivity estimation of the <<, >>, &<, &> and && operators,
as well as the normal inequality operators: <, <=, >=, >. "range @> element"
is also supported, but the range-variant @> and <@ operators are not,
because they cannot be sensibly estimated with lower and upper bound
histograms alone. We would need to make some assumption about the lengths of
the ranges for that. Alexander's patch included a separate histogram of
lengths for that, but I left that out of the patch for simplicity. Hopefully
that will be added as a followup patch.
The fraction of empty ranges is also calculated and used in estimation.
Tom Lane [Mon, 27 Aug 2012 02:48:55 +0000 (22:48 -0400)]
Fix up planner infrastructure to support LATERAL properly.
This patch takes care of a number of problems having to do with failure
to choose valid join orders and incorrect handling of lateral references
pulled up from subqueries. Notable changes:
* Add a LateralJoinInfo data structure similar to SpecialJoinInfo, to
represent join ordering constraints created by lateral references.
(I first considered extending the SpecialJoinInfo structure, but the
semantics are different enough that a separate data structure seems
better.) Extend join_is_legal() and related functions to prevent trying
to form unworkable joins, and to ensure that we will consider joins that
satisfy lateral references even if the joins would be clauseless.
* Fill in the infrastructure needed for the last few types of relation scan
paths to support parameterization. We'd have wanted this eventually
anyway, but it is necessary now because a relation that gets pulled up out
of a UNION ALL subquery may acquire a reltargetlist containing lateral
references, meaning that its paths *have* to be parameterized whether or
not we have any code that can push join quals down into the scan.
* Compute data about lateral references early in query_planner(), and save
in RelOptInfo nodes, to avoid repetitive calculations later.
* Assorted corner-case bug fixes.
There's probably still some bugs left, but this is a lot closer to being
real than it was before.
Tom Lane [Fri, 24 Aug 2012 17:09:04 +0000 (13:09 -0400)]
Fix issues with checks for unsupported transaction states in Hot Standby.
The GUC check hooks for transaction_read_only and transaction_isolation
tried to check RecoveryInProgress(), so as to disallow setting read/write
mode or serializable isolation level (respectively) in hot standby
sessions. However, GUC check hooks can be called in many situations where
we're not connected to shared memory at all, resulting in a crash in
RecoveryInProgress(). Among other cases, this results in EXEC_BACKEND
builds crashing during child process start if default_transaction_isolation
is serializable, as reported by Heikki Linnakangas. Protect those calls
by silently allowing any setting when not inside a transaction; which is
okay anyway since these GUCs are always reset at start of transaction.
Also, add a check to GetSerializableTransactionSnapshot() to complain
if we are in hot standby. We need that check despite the one in
check_XactIsoLevel() because default_transaction_isolation could be
serializable. We don't want to complain any sooner than this in such
cases, since that would prevent running transactions at all in such a
state; but a transaction can be run, if SET TRANSACTION ISOLATION is done
before setting a snapshot. Per report some months ago from Robert Haas.
Back-patch to 9.1, since these problems were introduced by the SSI patch.
Kevin Grittner and Tom Lane, with ideas from Heikki Linnakangas
Tom Lane [Thu, 23 Aug 2012 21:25:10 +0000 (17:25 -0400)]
Fix cascading privilege revoke to notice when privileges are still held.
If we revoke a grant option from some role X, but X still holds the option
via another grant, we should not recursively revoke the privilege from
role(s) Y that X had granted it to. This was supposedly fixed as one
aspect of commit 4b2dafcc0b1a579ef5daaa2728223006d1ff98e9, but I must not
have tested it, because in fact that code never worked: it forgot to shift
the grant-option bits back over when masking the bits being revoked.
Per bug #6728 from Daniel German. Back-patch to all active branches,
since this has been wrong since 8.0.
Tom Lane [Thu, 23 Aug 2012 03:55:34 +0000 (23:55 -0400)]
Remove overly-pessimistic statement about constraint exclusion.
As of 9.2, constraint exclusion should work okay with prepared statements:
the planner will try custom plans with actual values of the parameters,
and observe that they are a lot cheaper than the generic plan, and thus
never fall back to using the generic plan. Noted by Tatsuhito Kasahara.
Tom Lane [Wed, 22 Aug 2012 18:04:02 +0000 (14:04 -0400)]
Fix erroneous documentation of synchronous_commit = remote_write.
The docs claimed that this mode only waits for the standby to receive WAL
data, but actually it waits for the data to be written out to the standby's
OS; which is a pretty significant difference because it removes the risk of
crash of the walreceiver process.
Peter Eisentraut [Wed, 22 Aug 2012 03:42:43 +0000 (23:42 -0400)]
Fix install-strip on Mac OS X
There was a hack put into install-sh to call strip with the correct
options on Mac OS X. But that never worked, because configure
disabled stripping on that platform altogether. So remove that dead
code, and while we're at it, update install-sh to the latest upstream
source (from Automake).
Instead, set up the right strip options in programs.m4, so this now
actually works the way it was originally intended.
Tom Lane [Tue, 21 Aug 2012 22:41:52 +0000 (18:41 -0400)]
Avoid somewhat-theoretical overflow risks in RecordIsValid().
This improves on commit 51fed14d73ed3acd2282b531fb1396877e44e86a by
eliminating the assumption that we can form <some pointer value> +
<some offset> without overflow. The entire point of those tests is that
we don't trust the offset value, so coding them in a way that could wrap
around if the buffer happens to be near the top of memory doesn't seem
sound. Instead, track the remaining space as a size_t variable and
compare offsets against that.
Also, improve comment about why we need the extra early check on
xl_tot_len.
Tom Lane [Tue, 21 Aug 2012 19:18:36 +0000 (15:18 -0400)]
Fix dumping of security_barrier views with circular dependencies.
If a view has circular dependencies, pg_dump splits it into a CREATE TABLE
and a CREATE RULE command to break the dependency loop. However, if the
view has reloptions, those options cannot be applied in the CREATE TABLE
command, because views and tables have different allowed reloptions so
CREATE TABLE would reject them. Instead apply the reloptions after the
CREATE RULE, using ALTER VIEW SET.
Robert Haas [Tue, 21 Aug 2012 15:47:10 +0000 (11:47 -0400)]
Improve C comments in GetSnapshotData.
Move discussion of why our algorithm for taking snapshots in recovery
to a more appropriate location in the function, and delete incorrect
mention of taking a lock.
Peter Eisentraut [Tue, 21 Aug 2012 04:03:32 +0000 (00:03 -0400)]
Teach compiler that ereport(>=ERROR) does not return
When elevel >= ERROR, we add an abort() call to the ereport() macro to
give the compiler a hint that the ereport() expansion will not return,
but the abort() isn't actually reached because the longjmp happens in
errfinish().
Because the effect of ereport() varies with the elevel, we cannot use
standard compiler attributes such as noreturn for this.
Tom Lane [Mon, 20 Aug 2012 17:24:52 +0000 (13:24 -0400)]
Fix bugs in contrib/pg_trgm's LIKE pattern analysis code.
Extraction of trigrams did not process LIKE escape sequences properly,
leading to possible misidentification of trigrams near escapes, resulting
in incorrect index search results.
Don't get confused if a WAL partial record header has xl_tot_len == 0.
If a WAL record header was split across pages, but xl_tot_len was 0, we
would get confused and conclude that we had already read the whole record,
and proceed to CRC check it. That can lead to a crash in RecordIsValid(),
which isn't careful to not read beyond end-of-record, as defined by
xl_tot_len.
Add an explicit sanity check for xl_tot_len <= SizeOfXlogRecord. Also,
make RecordIsValid() more robust by checking in each step that it doesn't
try to access memory beyond end of record, even if a length field in the
record's or a backup block's header is bogus.
Tom Lane [Sat, 18 Aug 2012 18:10:17 +0000 (14:10 -0400)]
Another round of planner fixes for LATERAL.
Formerly, subquery pullup had no need to examine other entries in the range
table, since they could not contain any references to the subquery being
pulled up. That's no longer true with LATERAL, so now we need to be able
to visit rangetable subexpressions to replace Vars referencing the
pulled-up subquery. Also, this means that extract_lateral_references must
be unsurprised at encountering lateral PlaceHolderVars, since such might be
created when pulling up a subquery that's underneath an outer join with
respect to the lateral reference.