This removes a whole set of GUCs which are no longer used in the
codebase. Also remove relevant documentation.
Reviewed-by: NAshwin Agrawal <aagrawal@pivotal.io>
Reviewed-by: NHeikki Linnakangas <hlinnakangas@pivotal.io>
Reviewed-by: NGeorgios Kokolatos <gkokolatos@pivotal.io>

* reword from 'experimental' to 'beta'

* Experimental -> Beta in markdown source

* typo fix

* Removing SuSE 11 details in Beta notes

* docs - update compression information
-Add a topic that lists features that support configuring compression.
-update gp_workfile_compression GUC. Remove requirement to install zstd.

* docs - update compression information based on review comments.
-changed description to point to feature/utility for specific compression information.
-added general, pivotal, and OSS specific information about compression requirements.

* docs - compression information - reivew edit.

This re-implements compression that was lost in the WorkFile/BufFile
refactoring. This new implementation uses Zstandard rather than zlib.

Compression can be enabled with "gp_workfile_compression=on". It is
disabled by default.
Reviewed-by: NMel Kiyama <mkiyama@pivotal.io>
Reviewed-by: NYandong Yao <yyao@pivotal.io>

Temporary files have been somewhat inconsistent across different
operations. Some operations used the Greenplum-specific "workfile" API,
while others used the upstream BufFile API directly.

The workfile API provides some extra features: workfiles are visible in
the gp_toolkit views, and you can limit their size with the
gp_workfile_limit_* GUCs. The temporary files that didn't go through the
workfile API were exempt, which is not cool.

To make things consistent, remove the workfile APIs. Use BufFiles
directly everywhere. Re-implement the user-facing view and tracking the
limits, on top of the BufFile API, so that those features are not lost.

The workfile API also supported compressing the temporary files using
zlib. That feature is lost with this commit, but will be re-introduced by
the next commit.

Another feature that this removes, is checksumming temporary files.
That doesn't seem very useful, so we can probably live without it. But
if it's still needed, then that should also be re-implemented on top
of the BufFile API later.

Discussion: https://groups.google.com/a/greenplum.org/d/msg/gpdb-dev/8Xe9MGor0pM/SjqiOo83BAAJReviewed-by: NMel Kiyama <mkiyama@pivotal.io>
Reviewed-by: NYandong Yao <yyao@pivotal.io>

* docs - remove gptransfer from docs
--removed gptransfer topics, references to gptransfer, and images.
--also updated text in gpcopy-migrate as rough update for 6.0

* docs - remove gptransfer from docs - review updates

* Docs - update docs to note that system columns are unavailable in
queries on replicated tables.

* Edits from reviewers

* docs - migrate using gpcopy- remove same number of source, dest. hosts restriction.

* docs - migrate using gpcopy- updates based on review comments.

* docs - remove track_count GUC

* docs - removed GUC track_activities

will be backported to 5X_STABLE

* docs - gpbackup S3 plugin - changes to S3 authentication.

Credentials no longer required in config file.
Information can be set in session environment.

* ocs - gpbackup S3 plugin - review comment updates.

* docs - gpbackup S3 plugin - a fix to updates.

The support for sending alerts via Email or SNMP was quite a kludge,
and there are much better external tools for managing alerts than
what we can supply in core anyways so this retires the capability.

All references to alert sending in the docs are removed, but there
needs to be section written about how to migrate off this feature
in the release notes or a similar location.

Discussion: https://github.com/greenplum-db/gpdb/pull/6384

Given the online gpexpand work, the gp_num_contents_in_cluster GUC is
unused. So, delete the same from code to avoid confusions and eliminate this
long argument required to start a postgres instance in gpdb.

Commit 17f9b7f070dbe17b2844a8b4dd428 in the pgweb repository removed
the /static/ portion on all doc URLs, leaving a redirect in place. To
avoid incurring a needless redirect, remove the /static/ part in the
links to the PostgreSQL documentation.

The /static/ URLs stem from a time when there were interactive docs
that had comment functionality. These docs were removed a very long
time ago, but the static differentiator was left in place until now.

Reviewed-by: Mel Kiyama

Reviewed-by: NJacob Champion <pchampion@pivotal.io>
Reviewed-by: NMel Kiyama <mkiyama@pivotal.io>

* docs - gpcopy new option --on-segment-threshold

* docs - gpcopy review updates

* docs - gpcopy fix typo host -> source

* docs - remove gpcopy limitation of same number of segments on source dest. systems

Now there is only the async dispatcher.  The dispatcher API interface is
kept so we might add new backend in the future.

The GUC gp_connections_per_thread is also retired which was used to
switch between the async and threaded backends.

* docs - gpbackup - add limitation for simultaneous DDL operations.

This will be backported to 5X_STABLE

* docs - gpbackup - update limitation for simultaneous DDL operations.

-How to find the boostfs config. guide
-How to find the boostfs RPM

* docs - fixing bloat - add note about performing reindex on system tables.

* docs - fixing bloat - note about reindex - review comment updates

This GUC is now unused after the major COPY refactor.
Co-authored-by: NChris Hajas <chajas@pivotal.io>
Co-authored-by: NKevin Yeap <kyeap@pivotal.io>

* docs - gpbackup -incremental backups

--New Admin. Guide topic describing incremental backups
--Updates to gpbackup/gprestore Admin Topic for history file.
--Updates to gpbackup/gprestore reference for new functionality

Links to HTML documents on the GPDB review site

new incremental backup topic
http://docs-gpdb-review-staging.cfapps.io/review/admin_guide/managing/backup-gpbackup-incremental.html

updated admin topic - gpbackup history file.
http://docs-gpdb-review-staging.cfapps.io/review/admin_guide/managing/backup-gpbackup.html

Updated gpbackup/gprestore reference topics
http://docs-gpdb-review-staging.cfapps.io/review/utility_guide/admin_utilities/gpbackup.html
http://docs-gpdb-review-staging.cfapps.io/review/utility_guide/admin_utilities/gprestore.html

* docs - gpbackup - review comment updates to incremental backup

--updates and edits based on review comments
--corrected compression option information
--corrected --with-stats information. moved to Notes section
--reorganized Admin Guide sections based on review comments

HTML review site has been updated.

* docs - gpbackup - more review comment updates to incremental backup

* docs- gpbackup - incremental backup - minor edits from review comments

-Removed Warning - plugin is experimental feature.
-Removed limitation to use --single-data-file or --metadata-only with --plugin

Will be backported to 5X_STABLE

- Created the needed control files
- Renamed and adapted the installation script
- Remove redundant tests in regress that were just checking installation
- Add tests to ensure installation is successfull
- Updated the Makefile to support the extension and add information
about regression tests
- Add contrib/gp_internal_tools tests to ICW
- Remove session_level_memory_consumption from regress test suite

* docs - fix some pivnet links

* add missing space

* docs - remove duplicate gphdfs/kerberos topic in best practices

* remove unused file

* docs - update gpbackup API - add segment instance and update backup directory information.

Also update API version to 0.3.0.

This will be ported to 5X_STABLE

* docs - gpbackup API - review updates and fixes for scope information

Also, cleanup edits.

* docs - gpbackup API - more review updates and fixes to scope information.

* docs - gpbackup S3 plugin - support for S3 compatible data stores.

Link to HTML format on GPDB docs review site.
http://docs-gpdb-review-staging.cfapps.io/review/admin_guide/managing/backup-s3-plugin.html

* docs - gpbackup S3 plugin - review comment updates

* docs - gpbackup S3 plugin - Add OSS/Pivotal support information.

* docs - gpbackup S3 plugin - fix typos.

* docs - gpbackup S3 plugin - updated information about S3 compatible data stores.

* docs - gpbackup API - update for scope argument.

This will be ported to 5X_STABLE

* docs - gpbackup API - correct API scope description based on review comments.

* docs - gpbackup API - edit scope description based on review comments.

--Updated API version

* docs - gpcopy new options --dry-run, --no-distribution-check

--Add limitation and warning about copying some types of partitioned tables with --no-distribution-check.
--Also added limitation and warning to Admin Guide.

* docs - gpcopy fix typo for new option --no-distribution-check

* docs - gpcopy new options. Removed unneeded xref.

Instead of completely disabling the generation of Paths with disabled
plan types, add a high penalty to their cost estimates, like in the
upstream. This reduces our diff vs. upstream, making future merges more
straightforward.

Discussion: https://groups.google.com/a/greenplum.org/d/msg/gpdb-dev/Az2cDcqf73g/_tY6Yv1kBgAJCo-authored-by: NDaniel Gustafsson <dgustafsson@pivotal.io>
Reviewed-by: NVenkatesh Raghavan <vraghavan@pivotal.io>
Reviewed-by: NRichard Guo <riguo@pivotal.io>

* docs - update system catalog maintenance information.

--Updated Admin. Guide and Best Practices for running REINDEX, VACUUM, and ANALYZE
--Added note to REINDEX reference about running ANALYZE after REINDEX.

* docs - edits for system catalog maintenance updates

* docs - update recommendation for running vacuum and analyze.

Update based on dev input.

--change command that tests email notification to a psql command.
--remove old example that uses gmail public SMTP server

* docs - gpbackup/gprestore new functionality.

--gpbackup new option --jobs to backup tables in parallel.
--gprestore  --include-table* options support restoring views and sequences.

* docs - gpbackup/gprestore. fixed typos. Updated backup/restore of sequences and views

* docs - gpbackup/gprestore - clarified information on dependent objects.

* docs - gpbackup/gprestore - updated information on locking/quiescent state.

* docs - gpbackup/gprestore - clarify connection in --jobs option.