Docs: Updating CREATE INDEX reference with changes from PR 3339

The current behavior is to check for the existence of dumps dirs and, unless
run with the -f flag, error out if they do. This commit extends this
check to backups.

Author: Nadeem Ghani <nghani@pivotal.io>

Leverage perfmon stat sender procees to call a hook function for cluster
level info collection.

Without changing existing behavior of stat sender process, this commit
changed the interval in main loop of stat sender from 1 second to 100 ms
because cluster info collector requires a finer granularity of sampling.
With this change, stats sender process should be started when
gp_enable_query_metrics is on.

Author: Wang Hao <haowang@pivotal.io>
Author: Zhang Teng <tezhang@pivotal.io>

The hook is called for
 - each query Submit/Start/Finish/Abort/Error
 - each plan node, on executor Init/Start/Finish

Author: Wang Hao <haowang@pivotal.io>
Author: Zhang Teng <tezhang@pivotal.io>

On postmaster start, additional space in Shmem is allocated for Instrumentation
slots and a header. The number of slots is controlled by a cluster level GUC,
default is 5MB (approximate 30K slots). The default number is estimated by 250
concurrent queries * 120 nodes per query. If the slots are exhausted,
instruments are allocated in local memory as fallback.

These slots are organized as a free list:
  - Header points to the first free slot.
  - Each free slot points to next free slot.
  - The last free slot's next pointer is NULL.

ExecInitNode calls GpInstrAlloc to pick an empty slot from the free list:
  - The free slot pointed by the header is picked.
  - The picked slot's next pointer is assigned to the header.
  - A spin lock on the header to prevent concurrent writing.
  - When GUC gp_enable_query_metrics is off, Instrumentation will
    be allocated in local memory.

Slots are recycled by resource owner callback function.

Benchmark result with TPC-DS shows performance impact by this commit is less than 0.1%
To improve performance of instrumenting, following optimizations are added:
  - Introduce instrument_option to skip CDB info collection
  - Optimize tuplecount in Instrumentation from double to uint64
  - Replace instrument tuple entry/exit function with macro
  - Add need_timer to Instrumentation, to allow eliminating of timing overhead.
    This is porting part of upstream commit:
------------------------------------------------------------------------
commit af7914c6
Author: Robert Haas <rhaas@postgresql.org>
Date:   Tue Feb 7 11:23:04 2012 -0500

Add TIMING option to EXPLAIN, to allow eliminating of timing overhead.
------------------------------------------------------------------------

Author: Wang Hao <haowang@pivotal.io>
Author: Zhang Teng <tezhang@pivotal.io>

The flakyness is caused by the Orca version bump to 2.53.11, in which Orca
improved the equivclasses for inner/outer join plan. Previously Orca generated
bad plan, causing OOM. But as of 2.53.11, Orca generated better plan, may not
cause OOM. Due to the flakyness of this test, remove it.

- Change gpdeletsystem to delete tablespaces before datadir
- Refactor SegmentStart.noWait to pg_ctrl_wait
- Create PgBaseBackup class
- Revert the change to default Mirror status
- Assorted typos and bugfixes

Author: Shoaib Lari <slari@pivotal.io>
Author: Jim Doty <jdoty@pivotal.io>
Author: Nadeem Ghani <nghani@pivotal.io>

Author: C.J. Jameson <cjameson@pivotal.io>

The gpexpand utility and associated code are modified to work with the WALREP
code.  Previously, gpexpand only worked with the primaries and relied on Filerep
to populate the mirrors. We are changing gpexpand such that it initializes the
mirrors using pg_basebackup and set them up for WAL replication.

Also, since the WALREP branch removed Filespaces, so we have also done the same
and replaced references to Filespaces by the Data Directory of the segments.

Author: Marbin Tan <mtan@pivotal.io>
Author: Shoaib Lari <slari@pivotal.io>
Author: Nadeem Ghani <nghani@pivotal.io>

* Add documentation and examples for COPY options

atmsort sometimes treats the triple-dash as the beginning of a table,
which screws up sorting. Use double-dashes to assist with debugging
failures.

- Stagger kickoff based on prod/dev and number of sections
- Also suggest dev pipeline command has a git-branch

Author: Jim Doty <jdoty@pivotal.io>
Author: C.J. Jameson <cjameson@pivotal.io>

* Update readme instructions for using docker for building GPDB

It works fine without all those links in each and every directory in source code
so remove the extra work and annoyance.

The common situation was doing a big rebase of a branch: a conflicting
diff shows up in the template file as well as the generated pipeline.

The right way to handle that situation is resolve the diff in the
template and then regenerate the pipeline (rather than resolving the
diff in the generated file)

However, before this change, the pipeline validation was happening
before the new pipeline was generated, and thus the yaml parsing choked
on the git merge conflict indicators `======`

Also, only print out the message if it passes validation.

Author: C.J. Jameson <cjameson@pivotal.io>
Author: Jim Doty <jdoty@pivotal.io>

Author: Xin Zhang <xzhang@pivotal.io>
Author: Asim R P <apraveen@pivotal.io>

Author: Xin Zhang <xzhang@pivotal.io>
Author: Asim R P <apraveen@pivotal.io>

Originaly, we use GUC gp_fts_probe_pause to skip FTS probe. However, in
order to change the FTS behavior, we need to signal the FTS process.
This will cause the test non-deterministic if the GUC value is used
before SIGHUP is handled by the backends to load the new value.

Using the fault injector, we directly set flag in the shared memory,
then immediately, FTS knows it will skip.

This will make the test more deterministic.

Author: Xin Zhang <xzhang@pivotal.io>
Author: Asim R P <apraveen@pivotal.io>

Replace rescan_requested and processing_fullscan with fullscan_requested
flag, and simpilfy the sleep logic in FtsLoop().

Author: Xin Zhang <xzhang@pivotal.io>
Author: Asim R P <apraveen@pivotal.io>

The pg_ctl response output for PQPING_MIRROR_READY was missing in
https://github.com/greenplum-db/gpdb/commit/b824fe8f269934987e30a4c177605b250703d20f. We
just need it to say the mirror has started.

Reported by Daniel Gustafsson in gpdb-dev mailing list:
https://groups.google.com/a/greenplum.org/forum/#!topic/gpdb-dev/oNrxvVEG-UY

The commit that broke win32 compilation:
https://github.com/greenplum-db/gpdb/commit/f9c7df6914b63487a10b319e998e611986b0d7ce

To fix this, we put some win32 ifdefs around Greenplum-specific code
around threading. We don't really compile windows server so this
should be fine for now to compile the windows CCL.

This is a partial backport of the below commit from PostgreSQL 9.1,
the part left out is documentation:

  commit 35eb0958
  Author: Peter Eisentraut <peter_e@gmx.net>
  Date:   Thu Jan 13 09:13:12 2011 +0200

    Don't run regression tests in SQL_ASCII encoding by default

    Instead, run them in the encoding that the locale selects, which is
    more representative of real use.

    Also document how locale and encoding for regression test runs can be
    selected.

If we avoid calling pg_regress with an empty --multibyte we
can skip GPDB specific handling of the encoding parameter in
pg_regress and instead follow upstream. While the local diffs
to pg_regress weren't wrong per se, avoiding merge conflicts
is of more interest.

Also revert the commented out MULTIBYTE in the makefile to
match the upstream value. A follow-up commit will fix this
as well.

The errcode thrown in an ereport() on a segment was passed back to
the dispatcher, but then dropped and replaced with a default errcode
of ERRCODE_DATA_EXCEPTION. This works for most situations, but when
trapping errors the exact errcode must be propagated. This extends
the API to extract the errcode as well. The below case illustrates
the previous issue:

  CREATE TABLE test1(id int primary key);
  CREATE TABLE test2(id int primary key);
  INSERT INTO test1 VALUES(1);
  INSERT INTO test2 VALUES(1);
  CREATE OR REPLACE FUNCTION merge_table() RETURNS void AS $$
  DECLARE
	v_insert_sql varchar;
  BEGIN
	v_insert_sql :='INSERT INTO test1 SELECT * FROM test2';
	EXECUTE v_insert_sql;
	EXCEPTION WHEN unique_violation THEN
		RAISE NOTICE 'unique_violation';
	END;
  $$ LANGUAGE plpgsql volatile;
  SELECT merge_table();

This information can be easily derived from CDXLColRef member of
CDXLScalarIdent. This now mirrors what is done in the ORCA types
CScalarIdent and CColRef.
Signed-off-by: NEkta Khanna <ekhanna@pivotal.io>

* Use PXF docker image to run PXF smoke

* Remove unused singlecluster resource

Author: Xin Zhang <xzhang@pivotal.io>
Author: Asim R P <apraveen@pivotal.io>

- Add libpython
- Add libevent
- Add libgcc_s