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

When an invalid query parameter is reported, some memory leaks.

found by Coverity

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 4b2dafcc, 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.

Just to check that they actually work.

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.

This is open to debate of course, but it's past time we had *something*
here.

A very large number of small improvements ...

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.

configuration file.

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.

This avoids a warning from clang 3.2 about an uninitialized variable
'dtype' in date_in().

I was unable to entirely resist the temptation to copy-edit related
entries, but will save most of that for a separate pass.

This improves on commit 51fed14d 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.

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.

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.

Craig Ringer, slightly edited by me.

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.

Jeff Janes

Jeff Janes

Extraction of trigrams did not process LIKE escape sequences properly,
leading to possible misidentification of trigrams near escapes, resulting
in incorrect index search results.

Fujii Masao

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.

Per report and analysis by Tom Lane.

Now that we have LATERAL, it's fairly painless to allow this case, which
was left as a TODO in the original multi-row VALUES implementation.

It said "XXX: The following could be improved if we had LATERAL" ...
so let's do that.

No catversion bump since either version of the view works fine.