Discussion: https://github.com/greenplum-db/gpdb/pull/6410
Reviewed-by: Heikki Linnakangas

* Update DITA docs with Postgres 8.4 merge, interation 3 changes to SGML files.
(PR #3780)

* Update DITA docs with Postgres 8.4 merge, interation 3 changes to SGML files.
(PR #3780)

* Fix example syntax

* Add missing <p> codes and move into sectiondiv

* Update gp_create_table_random_default_distribution to describe new 6.x rules

* Update from Daniel

* Using same wording for behavior in CREATE TABLE

Allow specifying multiple UNIQUE constraints in the CREATE TABLE command,
or PRIMARY KEY and UNIQUE constraints, as long as they are all compatible
with the DISTRIBUTED BY clause.

Don't require the constraint's key columns to be a left-subset of the
DISTRIBUTED BY clause. It still needs to be a subset, but any subset will
do.

Likewise adjust the rules for deriving the distribution key from the
constraints, if no DISTRIBUTED BY was given, to choose the largest common
subset across all constraints.

Discussion: https://groups.google.com/a/greenplum.org/d/msg/gpdb-dev/OJzz8I6WuVI/tMB8GcXdAgAJ

* Modify SQL references for replicated tables

* Changes for edits and review comments

* docs - add foreign data wrapper-related ref pages

* remove CREATE SERVER example referencing default fdw

* edits from david, and his -> their

* docs - add distribution and skew topic, address random dist skew

* clarify single tuple assigned to first segment

* docs - type SET DEFAULT ENCODING

* edits requested by david

* add gp-specific clauses to summary of greenplum features page

* docs - review zstd doc additions, misc related edits

* modify ddl storage example 1 to use zstd

Add a new compression option for append-optimized tables, "zstd". It is
generally faster than zlib or quicklz, and compresses better. Or at least
it can be faster or compress better, if not both at the same time, by
adjusting the compression level. A major advantage of Zstandard is the wide
range of tuning, to choose the trade-off between compression speed and
ratio.

Update documentation to mention "zstd" alongside "zlib" and "quicklz". More
could be done; all the examples still use zlib or quicklz, for example, and
I think we want to emphasize Zstandard more in the docs, over those other
options. But this is the bare minimum to keep the docs factually correct.

Using the new option requires building the server with the libzstd library.
A new --with-zstd option is added for that. The default is to build without
libzstd, for now, but we should probably change the default to be on, after
we have had a chance to update all the buildfarm machines to have libzstd.

Patch by Ivan Leskin, Dmitriy Pavlov, Anton Chevychalov. Test case, docs
changes, and some minor editorialization by Heikki Linnakangas.

* docs: create table- fixed default storage options information
default storage options can be set for system, database, user.

* Small edit to keep it in line with the 4.3.x commit.

* rewording/conditionalizing more Pivotal-specific info

* conditionalizing/editing/or getting rid of more Pivotal-specific references and info

* GPDB DOCS - Fix issues found when validating files in gpdb-webhelp.ditamap.

* fix for GUC gp_connections_per_thread update to GPDB 5 description.

* add to release notes, update wording

* relnotes edits

* rebase and fix

* updating adminguide source with most recent 4.3.x work

* updating reference manual with most recent 4.3.x work

* updating utility guide with most recent 4.3.x changes

* updating client tools guide with most recent 4.3.x changes

* adding new file for client tools

* updating map files with most recent 4.3.x changes

* updating map files with most recent 4.3.x changes

* Revert "updating map files with most recent 4.3.x changes"

This reverts commit d7570343c17a126b4d11eaee3870ad6daa36966f.

* Revert "updating map files with most recent 4.3.x changes"

This reverts commit d7570343c17a126b4d11eaee3870ad6daa36966f.

* updating ditamaps with latest 4.3.x changes

* updating ditamaps with latest 4.3.x changes