* docs - enhance the pxf supported platforms section

* vendor -> bundle

* docs - update pxf supported platforms for v5.11

* combine 5.10 and 5.11 rows

* docs - pxf JAVA_HOME simplifications

* install java on master via ssh and the gphostfile

* address comments from oliver

* docs - pxf [cluster] sync now supports a delete option

* option and argument

* replace single dash with unicode

* misc edir

* docs - projection and pushdown info to tbl format; add parquet pushdown info

* combine arithmetic ops in single column

* multi-line header, center, combine is/not null

* add parquet data type write mapping

* docs - pxf jdbc connector supports bigint PARTITION_BY column

* int represents all integral types, 64-bit signed integer range

Backported from master 9aa9dc0apickReviewed-by: NMel Kiyama <mkiyama@pivotal.io>
Reviewed-by: NHeikki Linnakangas <hlinnakangas@pivotal.io>

This fixes multiple occurrences of duplicated words in sentences, like
"the the" and "is is" etc.

Backported from master 1d44a0c5Reviewed-by: NMel Kiyama <mkiyama@pivotal.io>
Reviewed-by: NHeikki Linnakangas <hlinnakangas@pivotal.io>

* docs - make pxf overview page more friendly

* address comments from david

* include db2 and msoft sql server in list of sql dbs supported

* docs - update pxf supported platform table for v5.10.1

* consolidate the rows in the table

* combine 5.8.1 and 5.8.2

* docs - pxf jdbc connector session authorization

* address comments from david

* WIP docs - pxf supports multiple kerberized hadoop clusters

* some of the edits requested by david

* change title again

* address some comments from alex and francisco

* impersonation default is on and other misc edits

* remove the optional upgrade steps

* fix formatting

* when hive w/kerb, initially comment out user impersonation property

* misc rewording on upgrade page

* misc edits from my final review

* docs - pxf supports writing avro data

* edits requested by franciso and oliver

* address comments from david

* docs - discuss parquet SCHEMA custom option

* capitalize Parquet

* file system location on the server

* reword per francisco

For one of the Hive authentication methods, the PXF documentation states
the incorrect identity used when Kerberos is enabled for Hive and the
hive.server2.enable.doAs property is false. The correct identity is the
Kerberos principal defined in the jdbc.url to connect to the Hive
database. Cherry-picked from 99784205

* docs - add pxf upgrade topic for greenplum 6.x

* clarify to newer version of 6.x

* docs - provide more detail about pxf s3 select FILE_HEADER option

* address review comments from david and francisco

* add error message returned when both order/names differ

* add ad steps in pxf krb doc

* From Lisa Owen

* distributing keytab using gpscp and gpssh

* Update gpdb-doc/markdown/pxf/pxf_kerbhdfs.html.md.erb
Co-Authored-By: NAlexander Denissov <denalex@users.noreply.github.com>

* Update gpdb-doc/markdown/pxf/pxf_kerbhdfs.html.md.erb
Co-Authored-By: NAlexander Denissov <denalex@users.noreply.github.com>

* misc formatting edits

* a few more formatting edits

* docs - add pxf 5to6 migration topic

* add step to migrate gphdfs to pxf

* add pxf 5to6 migration topic to oss subnav

* edits requested by alex and oliver

* add link to gphdfs-to-pxf migration doc

* edits requested by david

* docs - add gphdfs to pxf migration info

* some of the edits requested by francisco

* separate out config props that are not applicable to PXF

* use only major version num for 6, misc edits

* refactor info to include greenplum 4 migration source

* reorder from-4 migration to better match 5; update procedure

* misc edits requested by david

* docs - SERVER is required when accessing an object store

* fix formatting in new note

* docs - pxf: add s3-specific topic, add amazon s3 select topic

* remove DELIMITER specification in LOCATION URI plus upgrade considerations

* update OSS book subnav

* clarify delimiter in formatting options still required

* reword the upgrade step a bit

* edits requested by oliver

* minor edits requested by david

* docs - can now reset pxf on host and cluster

* remove the (re)s

* docs - pxf jdbc partition range improvements

* misc edits requested by david

* clarify use of RANGE and INTERVAL (hint), edits requested by francisco

* docs - pxf jdbc connection pooling

* edits requested by david

* use present tense in note

* misc edits requested by francisco

Backported from master 239d87e9

* docs - pxf now bundled with postgresql 42.2.5 jar

* remove postgresql jar registration from the example

* docs - pxf max tomcat threads now user-configurable

* misc edits