The maximal number of distributed by columns is 1600, gpdb should error out when
it exceeds the limitation. Another thing is gpdb should allocate enough memory to
hold those columns, otherwise it will cause memory overflow.

Three functions are available now:
- convert_from(bytea, name) returns text
- convert_to(text, name) returns bytea
- length(bytea, name) returns int

Related commits (partial codes are backported before OSS but not actived)

    commit a9742f12
    Author: Tom Lane <tgl@sss.pgh.pa.us>
    Date:   Wed Jan 9 23:43:54 2008 +0000

        Remove incorrect (and ill-advised anyway) pfree's in pg_convert_from and
        pg_convert_to.  Per bug #3866 from Andrew Gilligan.

    commit 02138357
    Author: Andrew Dunstan <andrew@dunslane.net>
    Date:   Mon Sep 24 01:29:30 2007 +0000

        Remove "convert 'blah' using conversion_name" facility, because if it
        produces text it is an encoding hole and if not it's incompatible
        with the spec, whatever the spec means (which we're not sure about anyway).

    commit 55613bf9
    Author: Andrew Dunstan <andrew@dunslane.net>
    Date:   Tue Sep 18 17:41:17 2007 +0000

        Close previously open holes for invalidly encoded data to enter the
        database via builtin functions, as recently discussed on -hackers.

        chr() now returns a character in the database encoding. For UTF8 encoded databases
        the argument is treated as a Unicode code point. For other multi-byte encodings
        the argument must designate a strict ascii character, or an error is raised,
        as is also the case if the argument is 0.

        ascii() is adjusted so that it remains the inverse of chr().

        The two argument form of convert() is gone, and the three argument form now
        takes a bytea first argument and returns a bytea. To cover this loss three new
        functions are introduced:
        . convert_from(bytea, name) returns text - converts the first argument from the
          named encoding to the database encoding
        . convert_to(text, name) returns bytea - converts the first argument from the
          database encoding to the named encoding
        . length(bytea, name) returns int - gives the length of the first argument in
          characters in the named encoding

    commit 75c6519f
    Author: Tatsuo Ishii <ishii@postgresql.org>
    Date:   Sun Mar 25 11:56:04 2007 +0000

        Add new encoding EUC_JIS_2004 and SHIFT_JIS_2004,
        along with new conversions among EUC_JIS_2004, SHIFT_JIS_2004 and UTF-8.
        catalog version has been bump up.

Committers: Kuien Liu and Haozhou Wang

more readable format.

Previously, gpcheckcat identified tables with missing attributes but
displayed them in various locations in the output in a
non-standardized format. This commit summarizes all the tables with missing
attributes in one section at the end of the output in the format
"[database].[schema].[table].[segment id]".

Authors: Chris Hajas and Jamie McAtamney

This commit fixes issues below:

extractContent() might forward NULL to marker.
ListBucket() fogets to delete keylist when errors happen.
contents in ListBucketResult are not cleared.
downloader is not destroyed in unit tests.
get_opt_s3() and truncate_options() in unit tests need to be freed.
xmlNodeGetContent() needs to be freed.
xml.ctxt->myDoc needs to be freed.
function for the XML library needs to be cleared.

Thanks to Kuien and Valgrind.

Signed-off-by: NNikos Armenatzoglou <nikos.armenatzoglou@gmail.com>

- print out all information about violated indexes in the logs
- changes unique index check to also return the list of violated
  segments in order to support this

- optimize query to find all unique indexes
- omit rows with null values when searching for violated indexes

- more accurate function names in GPObject
- remove duplication of query strings
- make file import for test subject independent of current working
  directory
- update test names to match casing convention

- additionally, minor refactoring in gpcheckcat and unique index check

- Before this we were adding issues to the report but not actually
  setting the checkStatus variable to False

Inheriting from GpTestCase instead of unittest.TestCase gives you:
- access to a logger via self.logger
- the ability to patch methods/objects by calling apply_patches with a list of patches
- automatic teardown of patches after tests are run
- hiding unittest dependency from the actual unit tests (e.g. overriding skip() and providing run_tests() to wrap main())

Also cleaned up unit tests for the unique index violation check

- mock pg.connect instead of patching gpcheckcat global method connect()
- use a magic mock for GV.cfg since we are trusting that it has been implemented properly

- includes unit tests for gpcheckcat covering everything after
  option parsing and everything before writing to stdout/logs
- in the process of rebasing, removes the tests for dropping leaked
  schemas.  These tests will be added back in the later commit
- adds a behave integration test for this check

- also adds unit test for this module
- returns table name, index name, table oid, and segment id of each
  violation

Along the way, fix trailing tabs and split a long error
message into two lines.

This will fix #524

A new version of libXML changes the output format, this patch
adapts the new "expected" file introduced in
PostgreSQL commit 085423e3.
Slight modifications by me.

This patch will not fail the current Pulse run in any way, because
the Pulse systems do not yet use the new libXML library, and therefore
are happy with xml.out and xml_1.out. I stripped down the regression
tests and this is the output without the patch:

parallel group (14 tests):  limit prepare conversion xml rowtypes copy2 polymorphism sequence without_oid temp truncate domain rangefuncs alter_table
     limit                ... ok (0,24 sec)  (diff:0,07 sec)
     copy2                ... ok (2,44 sec)  (diff:0,07 sec)
     temp                 ... ok (3,83 sec)  (diff:0,07 sec)
     domain               ... ok (7,12 sec)  (diff:0,10 sec)
     rangefuncs           ... ok (12,15 sec)  (diff:0,09 sec)
     prepare              ... ok (0,49 sec)  (diff:0,06 sec)
     without_oid          ... ok (3,49 sec)  (diff:0,07 sec)
     conversion           ... ok (1,19 sec)  (diff:0,17 sec)
     truncate             ... ok (4,03 sec)  (diff:0,06 sec)
     alter_table          ... ok (27,88 sec)  (diff:0,32 sec)
     sequence             ... ok (3,18 sec)  (diff:0,08 sec)
     polymorphism         ... ok (3,13 sec)  (diff:0,11 sec)
     rowtypes             ... ok (2,17 sec)  (diff:0,09 sec)
     xml                  ... FAILED (1,69 sec)  (diff:0,39 sec)
test variadic_parameters  ... ok (1,57 sec)  (diff:0,07 sec)
test default_parameters   ... ok (0,68 sec)  (diff:0,07 sec)

=======================
 1 of 97 tests failed.
=======================

This is the output with the patch:

parallel group (14 tests):  limit prepare conversion xml rowtypes copy2 polymorphism sequence without_oid temp truncate domain rangefuncs alter_table
     limit                ... ok (0,21 sec)  (diff:0,10 sec)
     copy2                ... ok (1,95 sec)  (diff:0,06 sec)
     temp                 ... ok (3,41 sec)  (diff:0,26 sec)
     domain               ... ok (6,67 sec)  (diff:0,19 sec)
     rangefuncs           ... ok (11,55 sec)  (diff:0,09 sec)
     prepare              ... ok (0,41 sec)  (diff:0,06 sec)
     without_oid          ... ok (2,91 sec)  (diff:0,06 sec)
     conversion           ... ok (0,96 sec)  (diff:0,15 sec)
     truncate             ... ok (3,62 sec)  (diff:0,09 sec)
     alter_table          ... ok (25,79 sec)  (diff:0,22 sec)
     sequence             ... ok (2,89 sec)  (diff:0,06 sec)
     polymorphism         ... ok (2,50 sec)  (diff:0,09 sec)
     rowtypes             ... ok (1,87 sec)  (diff:0,12 sec)
     xml                  ... ok (1,54 sec)  (diff:0,30 sec)
test variadic_parameters  ... ok (1,43 sec)  (diff:0,07 sec)
test default_parameters   ... ok (0,43 sec)  (diff:0,07 sec)

======================
 All 97 tests passed.
======================

Fix #550

It didn't do anything useful AFAICS.

Currently, the gpconfig utility is exiting with status 0 when one of
the option parsing checks fail.  It should return 1 instead.

* Support the aggregation transition datatype to be "internal"

Backport below commits from upstream:

    commit 22d9ddbb
    Author: Tom Lane <tgl@sss.pgh.pa.us>
    Date:   Sat Aug 14 15:47:13 2010 +0000

        Fix planner to make a reasonable assumption about the amount of memory space
        used by array_agg(), string_agg(), and similar aggregate functions that use
        "internal" as their transition datatype.  The previous coding thought this
        took *no* extra space, since "internal" is pass-by-value; but actually these
        aggregates typically consume a great deal of space.  Per bug #5608 from
        Itagaki Takahiro, and fix suggestion from Hitoshi Harada.

        Back-patch to 8.4, where array_agg was introduced.

    commit 9e0247ab
    Author: Tom Lane <tgl@sss.pgh.pa.us>
    Date:   Fri Nov 14 19:47:50 2008 +0000

        In CREATE AGGREGATE, allow the transition datatype to be "internal", but only
        if the user is superuser.  This makes available to extension modules the same
        sort of trick being practiced by array_agg().  The reason for the superuser
        restriction is that you could crash the system by connecting up an
        incompatible pair of internal-using functions as an aggregate.  It shouldn't
        interfere with any legitimate use, since you'd have to be superuser to create
        the internal-using transition and final functions anyway.

Besides, we cannot find regression tests in above commits, so we
add a set of tests for this feature, a part of them come from
legacy extension "intagg" regression tests.

Conflicts:
	src/test/regress/expected/arrays.out
	src/test/regress/sql/arrays.sql

* add tests to #588: run with role of (non-)superuser

    #588: Support the aggregate's transype to be "internal"

Normally, the aggregate's transtype can't be a pseudo-type.
However, we can allow "internal" for functions that want to
pass pointers to private data structures; but allow that only
to superusers. Here we add tests to verify this constraint.

This code was commented out without providing any useful information
so remove to reduce clutter.

This closes #606

This mirrors the check in vacuum.c, for VACUUMing external tables. This was
missed in commit f995c59f, which replaced most of the old ANALYZE with
the upstream code.

Fixes issue #395, reported by George Caragea.

Space for bit addition to nullbitmap was missed while estimating if
block has space for new delta item or not. Since adding a delta value,
adds a false bit to nullbitmap, it needs to be added in space
calculation before inserting new item to block. Missing same maybe endup
in failure during block write due to block size overflow.

The qp_query_execution test was added to the tree in commit 9d19664c
and then further updated in 29a0fec8 but it's not present in any test
schedule. Add to the greenplum_schedule to include it when running
installcheck-good.

Backport below commit from upstream:

    commit d5768dce
    Author: Tom Lane <tgl@sss.pgh.pa.us>
    Date:   Mon Feb 8 20:39:52 2010 +0000

        Create an official API function for C functions to use to check if they are
        being called as aggregates, and to get the aggregate transition state memory
        context if needed.  Use it instead of poking directly into AggState and
        WindowAggState in places that shouldn't know so much.

        We should have done this in 8.4, probably, but better late than never.

        Revised version of a patch by Hitoshi Harada.

modified:   src/backend/executor/nodeAgg.c
modified:   src/include/fmgr.h

- use consistent spacing
- use spaces instead of tabs
- update nomenclature in gpcheckcat - rename 'test' to 'check'
  This is is to be more consistent and to avoid confusion with unit/integration
  tests in the future.  We purposely did not change 'test' in stdout and logs
  because integration tests for other parts of the system that call
  gpcheckcat currently fail if our output changes.  A future commit may
  change 'test' to 'check' in stdout in addition to fixing the aforementioned
  integration tests.

Authors: Chumki Roy and Stephen Wu

* drop leaked schemas before running gpcheckcat tests

  1. drop any leaked/orphaned schemas before running any of the gpcheckcat tests
  2. add unit and behave tests
  3. move gpcheckcat from gpMgmt/bin/lib to gpMgmt/bin
  4. misc refactoring

orphan/leaked schemas are temp schemas that are not associated with any session id.
There used to be a check for leaked temp schemas in gpcheckcat
which ended up creating a repair script.

* drop the database at the end of the behave test

* move the gpcheckcat bin to lib symlink before the copy to /Users/nikhilkak/git/gpdb/gpAux/greenplum-db-devel

* fix the if check before symlinking  gpcheckcat from bin to lib

closes #595