Get rid of the pernicious entanglement between planner and executor headers
introduced by commit 0b03e595.

Also, rearrange the CustomFoo struct/typedef definitions so that all the
typedef names are seen as used by the compiler.  Without this pgindent
will mess things up a bit, which is not so important perhaps, but it also
removes a bizarre discrepancy between the declaration arrangement used for
CustomExecMethods and that used for CustomScanMethods and
CustomPathMethods.

Clean up the commentary around ExecSupportsMarkRestore to reflect the
rather large change in its API.

Const-ify register_custom_path_provider's argument.  This necessitates
casting away const in the function, but that seems better than forcing
callers of the function to do so (or else not const-ify their method
pointer structs, which was sort of the whole point).

De-export fix_expr_common.  I don't like the exporting of fix_scan_expr
or replace_nestloop_params either, but this one surely has got little
excuse.

execCurrent.c's search_plan_tree() must recognize a CustomScan on the
target relation.  This would only be helpful for custom providers that
support CurrentOfExpr quals, which is probably a bit far-fetched, but
it's not impossible I think.  But even without assuming that, we need
to recognize a scanned-relation match so that we will properly throw
error if the desired relation is being scanned with both a CustomScan
and a regular scan (ie, self-join).

Also recognize ForeignScanState for similar reasons.  Supporting WHERE
CURRENT OF on a foreign table is probably even more far-fetched than
it is for custom scans, but I think in principle you could do it with
postgres_fdw (or another FDW that supports the ctid column).  This
would be a back-patchable bug fix if existing FDWs handled CurrentOfExpr,
but I doubt any do so I won't bother back-patching.

disuse_physical_tlist() must work for all plan types handled by
create_scan_plan().

Now that we have a policy of hiding varlena catalog fields behind
"#ifdef CATALOG_VARLEN", there is no need for their type names to be
acceptable to the C compiler.  And experimentation shows that it does
not matter to pgindent either.  (If it did, we'd have problems anyway,
since these typedefs are unreferenced so far as the C compiler is
concerned, and find_typedef fails to identify such typedefs.)

Hence, remove the phony typedefs that genbki.h provided to make
some varlena field definitions compilable.

In passing, rearrange #define's into what seemed a more logical order.

Per KaiGai Kohei.

In passing improve formatting of some code added in commit 30d7ae3c,
because otherwise pgindent will make a mess of it.

It's a false positive - the variable is only used when 'onleft' is true,
and it is initialized in that case. But the compiler doesn't necessarily
see that.

Each WAL record now carries information about the modified relation and
block(s) in a standardized format. That makes it easier to write tools that
need that information, like pg_rewind, prefetching the blocks to speed up
recovery, etc.

There's a whole new API for building WAL records, replacing the XLogRecData
chains used previously. The new API consists of XLogRegister* functions,
which are called for each buffer and chunk of data that is added to the
record. The new API also gives more control over when a full-page image is
written, by passing flags to the XLogRegisterBuffer function.

This also simplifies the XLogReadBufferForRedo() calls. The function can dig
the relation and block number from the WAL record, so they no longer need to
be passed as arguments.

For the convenience of redo routines, XLogReader now disects each WAL record
after reading it, copying the main data part and the per-block data into
MAXALIGNed buffers. The data chunks are not aligned within the WAL record,
but the redo routines can assume that the pointers returned by XLogRecGet*
functions are. Redo routines are now passed the XLogReaderState, which
contains the record in the already-disected format, instead of the plain
XLogRecord.

The new record format also makes the fixed size XLogRecord header smaller,
by removing the xl_len field. The length of the "main data" portion is now
stored at the end of the WAL record, and there's a separate header after
XLogRecord for it. The alignment padding at the end of XLogRecord is also
removed. This compansates for the fact that the new format would otherwise
be more bulky than the old format.

Reviewed by Andres Freund, Amit Kapila, Michael Paquier, Alvaro Herrera,
Fujii Masao.

Custom rules must come after pgxs inclusion, not before, because any
rule added before pgxs will break the default 'all' target.

Author: Cédric Villemain <cedric@2ndquadrant.fr>

In bug #12000, Andreas Kunert complained that the documentation was
misleading in saying "FROM T1 CROSS JOIN T2 is equivalent to FROM T1, T2".
That's correct as far as it goes, but the equivalence doesn't hold when
you consider three or more tables, since JOIN binds more tightly than
comma.  I added a <note> to explain this, and ended up rearranging some
of the existing text so that the note would make sense in context.

In passing, rewrite the description of JOIN USING, which was unnecessarily
vague, and hadn't been helped any by somebody's reliance on markup as a
substitute for clear writing.  (Mostly this involved reintroducing a
concrete example that was unaccountably removed by commit 032f3b7e.)

Back-patch to all supported branches.

That includes VACUUM on GIN, GiST and SP-GiST indexes, and B-tree indexes
large enough to cause page deletions in B-tree. Plus some other special
cases.

After this patch, the regression tests generate all different WAL record
types. Not all branches within the redo functions are covered, but it's a
step forward.

This can cause problems on Windows, where files that are still open
can't be unlinked.

Jeff Janes

In pg_receivexlog, in order to check whether the current WAL file is
being opened or not, its file descriptor has to be checked against -1
as an invalid value. But, oops, 7900e94 added the incorrect test
checking the descriptor against 1. This commit fixes that bug.

Back-patch to 9.4 where the bug was added.

Spotted by Magnus Hagander

When pg_receivexlog --slot is connecting to the server, at the shutdown
of the server, walsender keeps waiting for the last WAL record to be
replicated and flushed in pg_receivexlog. But previously pg_receivexlog
issued sync command only when WAL file was switched. So there was
the case where the last WAL was never flushed and walsender had to
keep waiting infinitely. This caused the server shutdown to get stuck.

pg_recvlogical handles this problem by calling fsync() when it receives
the request of immediate reply from the server. That is, at shutdown,
walsender sends the request, pg_recvlogical receives it, flushes the last
WAL record, and sends the flush location back to the server. Since
walsender can see that the last WAL record is successfully flushed, it can
exit cleanly.

This commit introduces the same logic as pg_recvlogical has,
to pg_receivexlog.

Back-patch to 9.4 where pg_receivexlog was changed so that it can use
the replication slot.

Original patch by Michael Paquier, rewritten by me.
Bug report by Furuya Osamu.

The regression test cases added in commits b2cbced9 et al depended in part
on the Russian timezone offset changes of Oct 2014.  While this is of no
particular concern for a default Postgres build, it was possible for a
build using --with-system-tzdata to fail the tests if the system tzdata
database wasn't au courant.  Bjorn Munch and Christoph Berg both complained
about this while packaging 9.4rc1, so we probably shouldn't insist on the
system tzdata being up-to-date.  Instead, make an equivalent test using a
zone change that occurred in Venezuela in 2007.  With this patch, the
regression tests should pass using any tzdata set from 2012 or later.
(I can't muster much sympathy for somebody using --with-system-tzdata
on a machine whose system tzdata is more than three years out-of-date.)

These comments don't seem to have been touched in a long time.  Make them
describe the current implementation rather than what was here last century,
and be a bit more explicit about the unreferenced-typedefs issue.

pg_dump/parallel.c was using realloc() directly with no error check.
While the odds of an actual failure here seem pretty low, Coverity
complains about it, so fix by using pg_realloc() instead.

While looking for other instances, I noticed a couple of places in
psql that hadn't gotten the memo about the availability of pg_realloc.
These aren't bugs, since they did have error checks, but verbosely
inconsistent code is not a good thing.

Back-patch as far as 9.3.  9.2 did not have pg_dump/parallel.c, nor
did it have pg_realloc available in all frontend code.

For <, <=, > and >= strategies, mark the first scan key
as already matched if scanning in an appropriate direction.
If index tuple contains no nulls we can skip the first
re-check for each tuple.

Author: Rajeev Rastogi
Reviewer: Haribabu Kommi
Rework of the code and comments by Simon Riggs

The r-tree AM that used it was removed back in 2005.

Peter Geoghegan

Allows pg_dump to use a snapshot previously defined by a concurrent
session that has either used pg_export_snapshot() or obtained a
snapshot when creating a logical slot. When this option is used with
parallel pg_dump, the snapshot defined by this option is used and no
new snapshot is taken.

Simon Riggs and Michael Paquier

Previously pg_receivexlog flushed WAL data only when WAL file was switched.
Then 3dad73e7 added -F option to pg_receivexlog so that users could control
how frequently sync commands were issued to WAL files. It also allowed users
to make pg_receivexlog flush WAL data immediately after writing by
specifying 0 in -F option. However feedback messages were not sent back
immediately even after a flush location was updated. So even if WAL data
was flushed in real time, the server could not see that for a while.

This commit removes -F option from and adds --synchronous to pg_receivexlog.
If --synchronous is specified, like the standby's wal receiver, pg_receivexlog
flushes WAL data as soon as there is WAL data which has not been flushed yet.
Then it sends back the feedback message identifying the latest flush location
to the server. This option is useful to make pg_receivexlog behave as sync
standby by using replication slot, for example.

Original patch by Furuya Osamu, heavily rewritten by me.
Reviewed by Heikki Linnakangas, Alvaro Herrera and Sawada Masahiko.

DST law changes in the Turks & Caicos Islands (America/Grand_Turk) and
in Fiji.  New zone Pacific/Bougainville for portions of Papua New Guinea.
Historical changes for Korea and Vietnam.

There was some confusion on how to record the case that the operation
unlinks the last non-leaf page in the branch being deleted.
_bt_unlink_halfdead_page set the "topdead" field in the WAL record to
the leaf page, but the redo routine assumed that it would be an invalid
block number in that case. This commit fixes _bt_unlink_halfdead_page to
do what the redo routine expected.

This code is new in 9.4, so backpatch there.

Buildfarm members with CLOBBER_CACHE_ALWAYS advised us that commit
85b506bb was mistaken in setting the relpersistence value of the
index directly in the relcache entry, within reindex_index.  The reason
for the failure is that an invalidation message that comes after mucking
with the relcache entry directly, but before writing it to the catalogs,
would cause the entry to become rebuilt in place from catalogs with the
old contents, losing the update.

Fix by passing the correct persistence value to
RelationSetNewRelfilenode instead; this routine also writes the updated
tuple to pg_class, avoiding the problem.  Suggested by Tom Lane.

Daniel Gustafsson

Break out the "dynamic statistics" views in the table from the
"collected statistics" ones. Could do with some more refactoring,
but this is a start.

When checking a table that has an inheritance tree marked,
if no child tables remain, we skip ANALYZE. This patch emits
a message to show that the action has been skipped.

Author: Etsuro Fujita
Reviewer: Furuya Osamu

This removes ATChangeIndexesPersistence() introduced by f41872d0
which was too ugly to live for long.  Instead, the correct persistence
marking is passed all the way down to reindex_index, so that the
transient relation built to contain the index relfilenode can
get marked correctly right from the start.

Author: Fabrízio de Royes Mello
Review and editorialization by Michael Paquier
                                     and Álvaro Herrera

Allegedly, the last remaining usages of that struct were removed by
0e99be1c.

Author: Peter Geoghegan

630cd144 added initdb --sync-only, for use by pg_upgrade, by just
exposing the existing fsync code. That's wrong, because initdb so far
had absolutely no reason to deal with tablespaces.

Fix --sync-only by additionally explicitly syncing each of the
tablespaces.

Backpatch to 9.3 where --sync-only was introduced.

Abhijit Menon-Sen and Andres Freund

Unlogged relations are only reset when performing a unclean
restart. That means they have to be synced to disk during clean
shutdowns. During normal processing that's achieved by registering a
buffer's file to be fsynced at the next checkpoint when flushed. But
ResetUnloggedRelations() doesn't go through the buffer manager, so
nothing will force reset relations to disk before the next shutdown
checkpoint.

So just make ResetUnloggedRelations() fsync the newly created main
forks to disk.

Discussion: 20140912112246.GA4984@alap3.anarazel.de

Backpatch to 9.1 where unlogged tables were introduced.

Abhijit Menon-Sen and Andres Freund

Unlogged relations are reset at the end of crash recovery as they're
only synced to disk during a proper shutdown. Unfortunately that and
later steps can fail, e.g. due to running out of space. This reset
was, up to now performed after marking the database as having finished
crash recovery successfully. As out of space errors trigger a crash
restart that could lead to the situation that not all unlogged
relations are reset.

Once that happend usage of unlogged relations could yield errors like
"could not open file "...": No such file or directory". Luckily
clusters that show the problem can be fixed by performing a immediate
shutdown, and starting the database again.

To fix, just call ResetUnloggedRelations(UNLOGGED_RELATION_INIT)
earlier, before marking the database as having successfully recovered.

Discussion: 20140912112246.GA4984@alap3.anarazel.de

Backpatch to 9.1 where unlogged tables were introduced.

Abhijit Menon-Sen and Andres Freund

The SELECT reference page didn't really address the question of when
aggregate function evaluation occurs, nor did the "expression evaluation
rules" documentation mention that CASE can't be used to control whether
an aggregate gets evaluated or not.  Improve that.

Per discussion of bug #11661.  Original text by Marti Raudsepp and Michael
Paquier, rewritten significantly by me.

The initial patch for RLS mistakenly included headers associated with
the executor and planner bits in rewrite/rowsecurity.h.  Per policy and
general good sense, executor headers should not be included in planner
headers or vice versa.

The include of execnodes.h was a mistaken holdover from previous
versions, while the include of relation.h was used for Relation's
definition, which should have been coming from utils/relcache.h.  This
patch cleans these issues up, adds comments to the RowSecurityPolicy
struct and the RowSecurityConfigType enum, and changes Relation->rsdesc
to Relation->rd_rsdesc to follow Relation field naming convention.

Additionally, utils/rel.h was including rewrite/rowsecurity.h, which
wasn't a great idea since that was pulling in things not really needed
in utils/rel.h (which gets included in quite a few places).  Instead,
use 'struct RowSecurityDesc' for the rd_rsdesc field and add comments
explaining why.

Lastly, add an include into access/nbtree/nbtsort.c for
utils/sortsupport.h, which was evidently missed due to the above mess.

Pointed out by Tom in 16970.1415838651@sss.pgh.pa.us; note that the
concerns regarding a similar situation in the custom-path commit still
need to be addressed.

Author: Michael Paquier

When ALTER TABLESPACE MOVE ALL was changed to be ALTER TABLE ALL IN
TABLESPACE, the ALTER TABLESPACE summary should have been adjusted back
to its original definition.

Patch by Thom Brown (thanks!).

Per complaint from Tom.

While at it, throw in some extra tests for nulls as well, and make sure
that the set of data we insert on the second round is not identical to
the first one.  Both measures are intended to improve coverage of the
test.

Also uncomment the ON COMMIT DROP clause on the CREATE TEMP TABLE
commands.  This doesn't have any effect for someone examining the
regression database after the tests are done, but it reduces clutter for
those that execute the script directly.

This function has a loop which can lead to uninterruptible process
"stalls" (actually infinite loops) when some bugs are triggered.  Avoid
that unpleasant situation by adding a check for interrupts in a place
that shouldn't degrade performance in the normal case.

Backpatch to 9.3.  Older branches have an identical loop here, but the
aforementioned bugs are only a problem starting in 9.3 so there doesn't
seem to be any point in backpatching any further.