Signed-off-by: NMarbin Tan <mtan@pivotal.io>

The gp_external_grant_privileges GUC was needed before 4.0 to let
non superusers create external tables for gphdfs and http protocols.
This GUC was however deprecated during the 4.3 cycle so remove all
traces of it. The utility of the GUC was replaced in 4.0 when rights
management for external tables was implemented with the normal GRANT
REVOKE framework so this has been dead code for quite some time.

Remove GUC, code which handles it, all references to it from the
documentation and a release notes entry.

* Implement bytea HEX encode/decode
this is from upstream commit a2a8c7a6
The primary reason for back patching is to allow pgadmin4 to work
Unfortunately there are a few hacks to make this work without Enum Config GUCs
mostly around setting the GUC as the target is an integer but the guc value is a string

* fixed regression tests \
removed unused code

The collapse_limit settings were bumped to 20 a long time ago with
the sample config left at the previous value of 8. Update the sample
to match reality.

Spotted by Jim Mccann

The feature was disabled, by removing it from guc.c, only months after
it was introduced, back in 2009. I'm not sure if it ever made it into a
public release. We have no plans to resurrect it, and it has surely
bitrotted so badly that even if we did, it would be better to start from
scratch.

This change should be publicized to driver maintainers at once and
release-noted as an incompatibility with previous releases.

(cherry picked from commit 0839f312)

Changes to doc/src/sgml/{config,syntax}.sgml ignored as they are not
present in gpdb.

Recent versions of the Linux system header files cause xlogdefs.h to
believe that open_datasync should be the default sync method, whereas
formerly fdatasync was the default on Linux.  open_datasync is a bad
choice, first because it doesn't actually outperform fdatasync (in fact
the reverse), and second because we try to use O_DIRECT with it, causing
failures on certain filesystems (e.g., ext4 with data=journal option).
This part of the patch is largely per a proposal from Marti Raudsepp.
More extensive changes are likely to follow in HEAD, but this is as much
change as we want to back-patch.

Also clean up confusing code and incorrect documentation surrounding the
fsync_writethrough option.  Those changes shouldn't result in any actual
behavioral change, but I chose to back-patch them anyway to keep the
branches looking similar in this area.

In 9.0 and HEAD, also do some copy-editing on the WAL Reliability
documentation section.

Back-patch to all supported branches, since any of them might get used
on modern Linux versions.

how often we do SSL session key renegotiation. Can be set to
0 to disable renegotiation completely, which is required if
a broken SSL library is used (broken patches to CVE-2009-3555
a known cause) or when using a client library that can't do
renegotiation.

synchronized-scanning behavior, and make pg_dump disable sync scans so that
it will reliably preserve row ordering.  Per recent discussions.

in particular correct the obsolete claim that it can't be changed once
any plans have been cached.

postgresql.conf comment to match.

copy-editing.

to validate the realm of the connecting user. By default
it's empty meaning no verification, which is the way
Kerberos authentication has traditionally worked in
PostgreSQL.

- create a separate archive_mode GUC, on which archive_command is dependent

- %r option in recovery.conf sends last restartpoint to recovery command

- %r used in pg_standby, updated README

- minor other code cleanup in pg_standby

- doc on Warm Standby now mentions pg_standby and %r

- log_restartpoints recovery option emits LOG message at each restartpoint

- end of recovery now displays last transaction end time, as requested
  by Warren Little; also shown at each restartpoint

- restart archiver if needed to carry away WAL files at shutdown

Simon Riggs

buffers that cannot possibly need to be cleaned, and estimates how many
buffers it should try to clean based on moving averages of recent allocation
requests and density of reusable buffers.  The patch also adds a couple
more columns to pg_stat_bgwriter to help measure the effectiveness of the
bgwriter.

Greg Smith, building on his own work and ideas from several other people,
in particular a much older patch from Itagaki Takahiro.

* stats_start_collector goes away; we always start the collector process,
unless prevented by a problem with setting up the stats UDP socket.

* stats_reset_on_server_start goes away; it seems useless in view of the
availability of pg_stat_reset().

* stats_block_level and stats_row_level are merged into a single variable
"track_counts", which controls all reports sent to the collector process.

* stats_command_string is renamed to track_activities.

* log_autovacuum is renamed to log_autovacuum_min_duration to better reflect
its meaning.

The log_autovacuum change is not a compatibility issue since it didn't exist
before 8.3 anyway.  The other changes need to be release-noted.

rows will normally never obtain an XID at all.  We already did things this way
for subtransactions, but this patch extends the concept to top-level
transactions.  In applications where there are lots of short read-only
transactions, this should improve performance noticeably; not so much from
removal of the actual XID-assignments, as from reduction of overhead that's
driven by the rate of XID consumption.  We add a concept of a "virtual
transaction ID" so that active transactions can be uniquely identified even
if they don't have a regular XID.  This is a much lighter-weight concept:
uniqueness of VXIDs is only guaranteed over the short term, and no on-disk
record is made about them.

Florian Pflug, with some editorialization by Tom.

Oleg Bartunov and Teodor Sigaev, but I did a lot of editorializing,
so anything that's broken is probably my fault.

Documentation is nonexistent as yet, but let's land the patch so we can
get some portability testing done.

redirect_stderr to logging_collector.
Original patch from Arul Shaji, subsequently modified by Greg Smith, and then
heavily modified by me.

displayed in the postmaster log.  This avoids Windows-specific problems with
localized time zone names that are in the wrong encoding, and generally seems
like a good idea to forestall other potential platform-dependent issues.
To preserve the existing behavior that all backends will log in the same time
zone, create a new GUC variable log_timezone that can only be changed on a
system-wide basis, and reference log-related calculations to that zone instead
of the TimeZone variable.

This fixes the issue reported by Hiroshi Saito that timestamps printed by
xlog.c startup could be improperly localized on Windows.  We still need a
simpler patch for that problem in the back branches, however.

before reporting a transaction committed.  Data consistency is still
guaranteed (unlike setting fsync = off), but a crash may lose the effects
of the last few transactions.  Patch by Simon, some editorialization by Tom.

and fsync WAL at convenient intervals.  For the moment it just tries to
offload this work from backends, but soon it will be responsible for
guaranteeing a maximum delay before asynchronously-committed transactions
will be flushed to disk.

This is a portion of Simon Riggs' async-commit patch, committed to CVS
separately because a background WAL writer seems like it might be a good idea
independently of the async-commit feature.  I rebased walwriter.c on
bgwriter.c because it seemed like a more appropriate way of handling signals;
while the startup/shutdown logic in postmaster.c is more like autovac because
we want walwriter to quit before we start the shutdown checkpoint.

I/O utilization, per discussion.

While at it, lower the autovacuum vacuum and analyze threshold values to 50
tuples.  It is a bit higher (i.e. more conservative) than what I originally
proposed but much better than the old values for small tables.

Documentation still being written, will be committed later.

Henry B. Hotz and Magnus Hagander

by Heikki and a little bit by me.

over a fairly long period of time, rather than being spat out in a burst.
This happens only for background checkpoints carried out by the bgwriter;
other cases, such as a shutdown checkpoint, are still done at full speed.

Remove the "all buffers" scan in the bgwriter, and associated stats
infrastructure, since this seems no longer very useful when the checkpoint
itself is properly throttled.

Original patch by Itagaki Takahiro, reworked by Heikki Linnakangas,
and some minor API editorialization by me.

tablespace(s) in which to store temp tables and temporary files.  This is a
list to allow spreading the load across multiple tablespaces (a random list
element is chosen each time a temp object is to be created).  Temp files are
not stored in per-database pgsql_tmp/ directories anymore, but per-tablespace
directories.

Jaime Casanova and Albert Cervera, with review by Bernd Helmle and Tom Lane.

Riggs, additional code and docs by me.  Per discussion.

processes to be running simultaneously.  Also, now autovacuum processes do not
count towards the max_connections limit; they are counted separately from
regular processes, and are limited by the new GUC variable
autovacuum_max_workers.

The launcher now has intelligence to launch workers on each database every
autovacuum_naptime seconds, limited only on the max amount of worker slots
available.

Also, the global worker I/O utilization is limited by the vacuum cost-based
delay feature.  Workers are "balanced" so that the total I/O consumption does
not exceed the established limit.  This part of the patch was contributed by
ITAGAKI Takahiro.

Per discussion.

rules to be defined with different, per session controllable, behaviors
for replication purposes.

This will allow replication systems like Slony-I and, as has been stated
on pgsql-hackers, other products to control the firing mechanism of
triggers and rewrite rules without modifying the system catalog directly.

The firing mechanisms are controlled by a new superuser-only GUC
variable, session_replication_role, together with a change to
pg_trigger.tgenabled and a new column pg_rewrite.ev_enabled. Both
columns are a single char data type now (tgenabled was a bool before).
The possible values in these attributes are:

     'O' - Trigger/Rule fires when session_replication_role is "origin"
           (default) or "local". This is the default behavior.

     'D' - Trigger/Rule is disabled and fires never

     'A' - Trigger/Rule fires always regardless of the setting of
           session_replication_role

     'R' - Trigger/Rule fires when session_replication_role is "replica"

The GUC variable can only be changed as long as the system does not have
any cached query plans. This will prevent changing the session role and
accidentally executing stored procedures or functions that have plans
cached that expand to the wrong query set due to differences in the rule
firing semantics.

The SQL syntax for changing a triggers/rules firing semantics is

     ALTER TABLE <tabname> <when> TRIGGER|RULE <name>;

     <when> ::= ENABLE | ENABLE ALWAYS | ENABLE REPLICA | DISABLE

psql's \d command as well as pg_dump are extended in a backward
compatible fashion.

Jan

Simon Riggs

log_min_messages does; and arrange to suppress the duplicative output
that would otherwise result from log_statement and log_duration messages.
Bruce Momjian and Tom Lane.

	o read global SSL configuration file
	o add GUC "ssl_ciphers" to control allowed ciphers
	o add libpq environment variable PGSSLKEY to control SSL hardware keys

Victor B. Wagner