When starting either an old or new postmaster, force it to place its Unix
socket in the current directory.  This makes it even harder for accidental
connections to occur during pg_upgrade, and also works around some
scenarios where the default socket location isn't usable.  (For example,
if the default location is something other than "/tmp", it might not exist
during "make check".)

When checking an already-running old postmaster, find out its actual socket
directory location from postmaster.pid, if possible.  This dodges problems
with an old postmaster having a configured location different from the
default built into pg_upgrade's libpq.  We can't find that out if the old
postmaster is pre-9.1, so also document how to cope with such scenarios
manually.

In support of this, centralize handling of the connection-related command
line options passed to pg_upgrade's subsidiary programs, such as pg_dump.
This should make future changes easier.

Bruce Momjian and Tom Lane

Formerly it would only show them for relkinds 'r' and 'f' (plain tables
and foreign tables).  However, as of 9.2, views can also have reloptions,
namely security_barrier.  The relkind restriction seems pointless and
not at all future-proof, so just print reloptions whenever there are any.

In passing, make some cosmetic improvements to the code that pulls the
"tableinfo" fields out of the PGresult.

Noted and patched by Dean Rasheed, with adjustment for all relkinds by me.

them.

We can detect whether the planner top level is going to care at all about
cheap startup cost (it will only do so if query_planner's tuple_fraction
argument is greater than zero).  If it isn't, we might as well discard
paths immediately whose only advantage over others is cheap startup cost.
This turns out to get rid of quite a lot of paths in complex queries ---
I saw planner runtime reduction of more than a third on one large query.

Since add_path isn't currently passed the PlannerInfo "root", the easiest
way to tell it whether to do this was to add a bool flag to RelOptInfo.
That's a bit redundant, since all relations in a given query level will
have the same setting.  But in the future it's possible that we'd refine
the control decision to work on a per-relation basis, so this seems like
a good arrangement anyway.

Per my suggestion of a few months ago.

If a PlaceHolderVar contains a pulled-up LATERAL reference, its minimum
possible evaluation level might be higher in the join tree than its
original syntactic location.  That in turn affects the ph_needed level for
any contained PlaceHolderVars (that is, those PHVs had better propagate up
the join tree at least to the evaluation level of the outer PHV).  We got
this mostly right, but mark_placeholder_maybe_needed() failed to account
for the effect, and in consequence could leave the inner PHVs with
ph_may_need less than what their ultimate ph_needed value will be.  That's
bad because it could lead to failure to select a join order that will allow
evaluation of the inner PHV at a valid location.  Fix that, and add an
Assert that checks that we don't ever set ph_needed to more than
ph_may_need.

are sometimes signed, sometimes unsigned.

Linking to other parts of the manual doesn't work when building the
standalone INSTALL document.

Jeff Janes

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?)

Both per suggestions from Merlin Moncure.

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.

This was removed in commit cd004067,
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.

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.

I had thought this case worked already, but perhaps I didn't re-test it
after adding extract_lateral_references() ...

checking an old running server.

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.

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.

Peter Eisentraut

Josh Kupershmidt

session, now that pg_terminate_backend() uses it.

Josh Kupershmidt

--enable-shared is about Plyton's configure, not ours.

queries on parent tables, per suggestion from Josh Berkus.

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.

port.  The last use was QNX, per Peter Eisentraut.

Jeff Janes

autovacuum activity.

Per report from Marc Mamin

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.

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.

Report and analysis by Matthias.

Per note from Peter Eisentraut.

As suggested by Etsuro Fujita, but with somewhat different wording.

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.

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.

Jeff Davis, somewhat edited by me

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.