* docs - pxf init/sync support to master standby

* edits requested by david

* edits requested by francisco and oliver

* pxf sync from master TO standby or seg host

* identify sync run on master in pxf sync option description

strncat unfortunately takes a misleading size argument which means
at most size from src. It is a bit of an antipattern in the string
family of functions and for that compilers will emit a warning if
it happens that the size argument matches the size of src, since that
is not what usually users of strncat want to do.

The usage of the function in the code was correct. However instead
of silencing the compiler, strncat was replaced with the dynamic buffer
family of operations that postgres provides for the frontend.

Also protect against an invalid read in case that the size of the
result is zero.
Reviewed-by: NAsim R P <apraveen@pivotal.io>
Reviewed-by: NDaniel Gustafsson <dgustafsson@pivotal.io>

The curl slist API properly handle NULLs so we can be less verbose
and skip the check before passing to the slist cleanup function.
Reviewed-by: NFrancisco Guerrero <aguerrero@pivotal.io>

The header callback was storing the response in the context, but as
it was never used we might as well save the memory and just return
the required return of the number of bytes we would've saved should
we have allocated.
Reviewed-by: NFrancisco Guerrero <aguerrero@pivotal.io>

The only time the internal buffer cleanup code was called was just
before freeing the entire context, so individually zeroing out the
members is pointless. Remove the function entirely and inline the
buffer freeing into the context cleanup codepath.

For zeroing the error buffer, it's only called right after allocating
the error buffer with palloc0() in the first place so the memory will
always be zeroed out when reaching here.
Reviewed-by: NFrancisco Guerrero <aguerrero@pivotal.io>

If strlen(addr) is zero then based on how get_dest_address() works
addr will be NULL, and pfree() on NULL is not permitted.  Also, we
know that addr will either be a non-empty string or NULL, so we can
just as well test for addr being NULL and avoid a strlen() call.

Fix by only pfreeing when addr is set. (this is in an elog(ERROR..)
context so freeing isn't terribly interesting but it also doesn't
hurt so I'm keeping the current codepath.)
Reviewed-by: NFrancisco Guerrero <aguerrero@pivotal.io>

The libchurl abstraction layer has many internal helper functions
which weren't marked static and thus exported. Fix by marking all
as static.
Reviewed-by: NFrancisco Guerrero <aguerrero@pivotal.io>

Spotted while reading code.

CI reported some read failures just after the write action, it's
probably because the write action is not flushed yet by AWS.

Sleep and retry if AWS returns "NoSuchKey" error. Update the workflow
but not the test cases because users might have the same issue.
Co-authored-by: NPeifeng Qiu <pqiu@pivotal.io>

This reverts commit 668558dd.

CI reported some read failures just after the write action, it's
probably because the write action is not flushed yet by AWS.

Sleep and retry if AWS returns "NoSuchKey" error. Update the workflow
but not the test cases because users might have the same issue.

Previously we error out in gp_replica_check test if the cluster is not in
synced, which is usually due to bugs revealed by previous tests, instead of
gp_replica_check itself.

Print more detailed message so that people are not confused with the status and
this failure reason of the gp_replica_check test.

* Updates to GUCs from Cyrille's reviews

* Revise description of temp_buffers to match 6.0 behavior

* Fix a couple typos

* For effective_cache_size GUC, show default in blocks and size.

* Docs - update pg_class and pg_index catalog table references

* dyozie review comments

The script used in pipelines that search for explain plan changes
lists those queries that have cost, row or plan changes. In many
cases the user will want to investigate those changes further.

A new set of options generates two directories that are easy to
compare, one contains the baseline plans, one file per plan, and
the other contains the changed plans of the test.

$ ~/workspace/gpdb/concourse/scripts/perfsummary.py --help
usage: perfsummary.py [-h] [--baseLog BASELOG] [--diffDir DIFFDIR]
                      [--diffThreshold DIFFTHRESHOLD] [--diffLevel DIFFLEVEL]
                      [log_file]

Summarize the test suite execute and explain log

positional arguments:
  log_file              log file with explain/execute output

optional arguments:
  -h, --help            show this help message and exit
  --baseLog BASELOG     specify a log file from a base version to compare to
  --diffDir DIFFDIR     request diff files to be created and specify a
                        directory to place diffs into
  --diffThreshold DIFFTHRESHOLD
                        specify a numerical threshold to record plan diffs
                        with a performance regression of more than n percent
  --diffLevel DIFFLEVEL
                        specify which diff files to generate: 1 = all diffs, 2
                        = ignore cost diffs, 3 = plan diffs only

Connectivity and loaders are no longer vendored. Loaders will be
merged into clients. Add script to create msi package.

Requires a working libpq.dll. Set CMAKE_PREFIX_PATH to a successful
client build.

Behavior of stat() is not stable across C Runtime versions.
Implementation of msvcrt.dll calls FindFirstFile(), while in normal
CRT that omes with Visual Studio or Redistribute packages, it calls
CreateFile().
CreateFile() is problematic here, if path is a pipe, it will open
the pipe once then close, causing the other side to connect to the
wrong pipe. Skip stat() if the name is pipe and pretend there is one.

- Don't include strings.h when build with MSVC
- C99 Syntax fix for struct initializer.
- Call event_set to initialize event struct. Later libevent version
expect this behavior.
- Use recv instead of read. Latest CRT implementation of read only
works on files, not sockets.

- Fix upstream build system for MSVC, add option to build.pl to
only build client tools.
- Add detection for MSVC SDK version. If this field is missing,
8.1 is assumed. The latest compiler will complain about this.
- Various small fixes

* Add a list of SQL keywords to the ref guide

* Fix error from review

* Update from review comment

Story: https://www.pivotaltracker.com/story/show/164917628

   The gp-integration-testing pipeline needs the gp-clients RC
   package as a input, and then create the clients RPM base on it.
   The custom installer patch also need it to build client bin installer.
Co-authored-by: NXiaoran Wang <xiwang@pivotal.io>
Co-authored-by: NShaoqi Bai <sbai@pivotal.io>
Co-authored-by: NBob Bao <bbao@pivotal.io>

ORCA Explain plans will now contain:
`Optimizer: Pivotal Optimizer (GPORCA) version 3.35.0`

instead of:
`Optimizer: PQO version 3.35.0`

Authored-by: Chris Hajas chajas@pivotal.io

Follow-up to the previous commit, which worked fine for CentOS6 but fell
apart with CentOS7.

Because our vendored Python doesn't contain an RPATH/RUNPATH pointer to
the location of its libpython, trying to execute it directly will result
in failures at link time. The previous commit took the approach that
greenplum_path.sh takes, which is to hardcode an LD_LIBRARY_PATH that
makes up for this bug. This approach works for CentOS6, which is running
Python 2.6 as its system version. On CentOS7, which has Python 2.7, the
LD_LIBRARY_PATH causes the system Python to use the vendored
libpython.so.2.7, and virtualenv fails.

Instead of forcing a cross-linking situation with LD_LIBRARY_PATH, fix
the problem in the vendored Python binary, by using patchelf to set up a
proper RUNPATH. (We originally tried to build our vendored Python with
an RPATH set at compile time, but the only way to do that without
knowing the eventual installation prefix is by setting a relative RPATH
using the `$ORIGIN` construct, and virtualenv is unfortunately
incompatible with that.) We do this on any platforms that provide a
patchelf binary, and do our best to limp along on all others.

Along the way, get rid of the run_behave.yml task, which has been
confusing us for the entirety of this work. CCP jobs now use
run_behave_on_ccp_cluster.yml consistently.
Co-authored-by: NKalen Krempely <kkrempely@pivotal.io>

To run behave tests, behave now needs to be installed in the PATH. The
correct version of behave can be installed with pip using

    pip install -r gpMgmt/requirements-dev.txt

For the CI tests, use virtualenv, which allows behave to be installed
while still using greenplum PYTHONPATH for our vendored python modules.
This is more of a problem for platforms like centos6 where the system
python is a different version than the vendored version.
Co-authored-by: NKalen Krempely <kkrempely@pivotal.io>
Co-authored-by: NMark Sliva <msliva@pivotal.io>
Co-authored-by: NDavid Krieger <dkrieger@pivotal.io>
Co-authored-by: NJacob Champion <pchampion@pivotal.io>

This variable name is not renamed in commit cb447dc4
And will lead to compile error when cassert enabled.

AppendOnlyStorageWrite and BufferedAppend are two helper struct to do insert
for AO tables. They share many variables, but some of them with same name but
different semantic. This PR corrects their names to be consistent.

Skip gprecoverseg tablespace tests until tablespaces successfully work
with pg_rewind.
Co-authored-by: NMark Sliva <msliva@pivotal.io>

Co-authored-by: NJacob Champion <pchampion@pivotal.io>

Create the tablespace directory on all segments to support
running multi-host tablespace tests.
Co-authored-by: NJacob Champion <pchampion@pivotal.io>

Shutting down the primaries using SIGKILL keeps the PID files around,
whereas SIGTERM more gracefully stops the primaries and removes the PID
files. When PID files hang around, it keeps future tests from being able
to create a cluster.

* update pl/r docs to use CREATE EXTENSION

* update pl/perl, /python, update deprecation notices, add CASCADE info

* Feedback from Chuck

* Update postgresql.org hrefs to 9.4

* Feedback from Lisa