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.

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.

reporting in contains invalid data.

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.

Evidently I failed to test a compile after my earlier header shuffling.

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.

Instead, place a forward struct declaration for struct catclist in
syscache.h.  This reduces header proliferation somewhat.

This lets files that are mere users of ResourceOwner not automatically
include the headers for stuff that is managed by the resowner mechanism.

Per Peter Geoghegan.

Since we're not installing this file anymore, it has no reason to exist,
other than as historical reference; but we have an SCM for that.

percentage column before count column.  Docs updated.

has no space before it.

Report by Erik Rijkers

Lane's correction.

David E. Wheeler

Clarify the compatibility notes about EXTRACT() and about statistics
timing columns.

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.

pg_restore.

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.

It was confusing symlinks with hard links.

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
8cb53654.
Per report from Brendan Byrd.

has been created by adding #include <stdlib.h> to parse.c.

per request from Kevin Grittner.

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.

Alexander Korotkov, heavily modified by me.

It still thought that the --xlog-method option argument could be
empty, as in a previous version of this feature.

Brad Davis

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.

for CREATE TABLE LIKE ... INCLUDING INDEXES.

Per report from david.sahagian@emc.com

the same as \copy.

ISO "T" timestamptz format.

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