This is a preparation of an upcoming random ICG pipeline job.  In that
pipeline job we will have tables created on different segments, so far
the only way to hack this behavior is by using the gp_debug_numsegments
extension.  We want to load and execute that extension for all the tests
without modifying them directly, so a hook mechanism is needed.

Added a pg_regress argument --prehook to set a hook.  A hook script
should be put under src/test/regress/{sql,input}/hooks/ directory,
depending on whether it need pg_regress to substitute the @@ tokens.  At
most one hook can be specied.  It can be set via make command like this:

    # suppose there is src/test/regress/sql/hooks/hookname.sql
    make installcheck EXTRA_REGRESS_OPTS=--prehook=hookname

This is a preparation of an upcoming random ICG pipeline job.  In that
pipeline job we will have tables created on different segments, so the
plans might be different expectation.  In atmsort.pm there is already an
argument -gpd_ignore_plans to ignore the plan diffs, but there was no
equivalence in pg_regress.

Added a pg_regress argument --ignore-plans to ignore plan diffs.  It can
be enabled via make command like this:

    make installcheck EXTRA_REGRESS_OPTS=--ignore-plans

The PostgreSQL 9.4 brought us the 'pg_lsn' datatype, which is functionally
equivalent. And we weren't actually using 'gpxlogloc' for anything,
anyway.

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.

Co-authored-by: NShoaib Lari <slari@pivotal.io>

Prior to this commit, we always did a lookup for the relationOid in QE.
The original intent of the code was to avoid lookup for relationOid by QE if it
has already been stashed in the IndexStmt.  This commit updates code for it
along with `partition_locking` test expected file.
Co-authored-by: NShoaib Lari <slari@pivotal.io>

Recently, ICW case 'select_into' failed intermittently, the error looks like

"CREATE TABLE selinto_schema.tmp3 (a,b,c)
 	   AS SELECT oid,relname,relacl FROM pg_class
 	   WHERE relname like '%c%';	-- OK
ERROR:  role "30973" does not exist"

The RCA is, case 'lock' should not run concurrently with 'select_into',
a minirepo is:

1. in 'lock' case
CREATE TABLE lock_tbl1 (a BIGINT);
CREATE ROLE regress_rol_lock1;
GRANT UPDATE ON TABLE lock_tbl1 TO regress_rol_lock1;
select oid, relname, relacl from pg_class where relname like '%c%';
  oid   |  relname  |                        relacl
--------+-----------+-------------------------------------------------------
 180367 | lock_tbl1 | {gpadmin=arwdDxt/gpadmin,regress_rol_lock1=w/gpadmin}

2. in 'select_into' test case
CREATE TABLE selinto_schema.tmp3 (a,b,c)
       AS SELECT oid,relname,relacl FROM pg_class
       WHERE relname like '%c%';

3. in 'lock' test case
DROP TABLE lock_tbl1;
DROP ROLE regress_rol_lock1;

4. in 'select_into' test case
select * from tmp3;
   a    |     b     |                     c
--------+-----------+--------------------------------------------
 180367 | lock_tbl1 | {gpadmin=arwdDxt/gpadmin,180370=w/gpadmin}

create table tmp4 as select * from tmp3;
NOTICE:  Table doesn't have 'DISTRIBUTED BY' clause. Creating a NULL policy entry.
ERROR:  role "180370" does not exist

In Step4, role 'regress_rol_lock1' has been dropped, so when it tries to parse
acl, it finds role "180370" does not exist, the error seems to be reasonable.

In upstream, test 'lock' doesn't run concurrently with 'select_into', I also notice
that we have two 'lock' test within parallel_schedule, so remove the first one
to match upstream and avoid the intermittent failure of 'select_into'

EvalPlanQual materializes the slot to a heap tuple, PRIVATE_tts_values point
to freed memory. We need to reset PRIVATE_tts_nvalid in ExecMaterializeSlot, to
prevent the following ExecFilterJunk from referencing the dangling pointer.

Previously the reshuffle node's numsegments is always
set to the cluster size. Now we have flexible gang & dispath
API, we should correct the numsegments field of reshuffle
node to set it as the its lefttree's flow->numsegments.
Co-authored-by: NShujie Zhang <shzhang@pivotal.io>
Co-authored-by: NZhenghua Lyu <zlv@pivotal.io>

In CREATE TABLE we used to decide numsegments from LIKE, INHERITS and
DISTRIBUTED BY clauses.  However we do not want partially distributed
tables to be created by end users, so change the logic to always create
tables with DEFAULT as numsegments.  We still allow developers to hack
the DEFAULT numsegments with the gp_debug_numsegments extension.

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

Old error:

ERROR:  cannot use expression as distribution key, because it is not hashable (cdbmutate.c:1329)

The new error is the same you get with CREATE TABLE. While we're at it,
also change "can't" contraction to "cannot" in the error message, to
follow the PostgreSQL error message guidelines.

Here revert four commits

1. Remove Master/Standby SyncRepWait Greenplum hack: 7f6066ea
2. Add alter system synchronous_standby_names to * when gpinitstandby -n 1136f2fb
3. Hot fix in gpinitstandby behave test failure: b6c77b2f
4. Remove unused variables, to silence compiler warnings 88a185a5

The first commit should revert, because gpinitstandby did not change correctly comform to the this commit.
It will cause If the standby is down, and the synchronous_standby_names is *, the cluster will not start and hang on

The second, third, fourth should revert, because it is relavent to the first commit.

Previously, when creating join path between CdbLocusType_SingleQE path
and CdbLocusType_SegmentGeneral path, we always add a motion on top
of CdbLocusType_SegmentGeneral path so even the join path is promoted
to executed on QD, the CdbLocusType_SegmentGeneral path can still be
executed to segments.
                     join (CdbLocusType_SingleQE)
					/    \
                   /      \
CdbLocusType_SingleQE     Gather Motion
                            \
                          CdbLocusType_SegmentGeneral

For example:
(select * from partitioned_table limit 1) as t1
Nested Loop
    ->  Gather Motion 1:1
	     ->  Seq Scan on replicated_table
    ->  Materialize
		 ->  Subquery Scan on t1
		    ->  Limit
			   ->  Gather Motion 3:1
	               ->  Limit
		               ->  Seq Scan on partitioned_table
replicated_table only store tuples on segments, so without
the gather motion, seq scan of replicated_table doesn't
provide tuples.

There is another problem, if join path is not promoted to
QD, the gather motion might be redundant, For example:

  (select * from replicated_table, (select * from
  partitioned_table limit 1) t1) sub1;

Gather Motion 3:1
  -> Nested Loop
      ->  Seq Scan on partitioned_table_2
      ->  Materialize
          ->  Broadcast Motion 1:3
              -> Nested Loop
                 ->  Gather Motion 1:1 (redundant motion)
	                 ->  Seq Scan on replicated_table
              ->  Materialize
		         ->  Subquery Scan on t1
		            ->  Limit
			             ->  Gather Motion 3:1
	                       ->  Limit
		                      ->  Seq Scan on partitioned_table

So in apply_motion_mutator(), we omit such redundant motion if
it's not gathered to top slice (QD). sliceDepth == 0 means it
is top slice, however, sliceDepth now is shared by both init
plans and main plan, so if main plan increased the sliceDepth,
init plan may omit the gather motion unexpectedly which create
a wrong results.

The fix is simple to reset sliceDepth for init plans

When Append node contains SingleQE subpath we used to put Append on ALL
the segments, however if the SingleQE is partially distributed then
apparently we could not put the SingleQE on ALL the segments, this
conflict could results in runtime or incorrect results.

To fix this we should put Append on SingleQE's segments.

In the other hand when there are multiple SingleQE subpaths we should
put Append on the common segments of SingleQEs.
Reviewed-by: NHeikki Linnakangas <hlinnakangas@pivotal.io>

There are 3 reshuffle tests, the ao one, the co one, and the heap one.
They share almost the same cases, but different on table names and
create table options.  There are also some differences caused when
adding regression tests, they are only added in one file but not others.

We want to keep minimal differences between these tests, so we ensure
that a regression test for ao also covers similar case for heap.  And
once we understand one of the test file we have almost the same
knowledge on the others.

Here is a list of changes to these tests:
- reduce differences on table names by using schema;
- reduce differences on CREATE TABLE options by setting default storage
  options;
- simplify the creation of partially distributed tables by using the
  gp_debug_numsegments extension;
- copy some regression tests to all the tests;
- retire the no longer used helper function;
- move the tests into an existing parallel test group;

pg_regress test framework provides some @@ tokens for ao/co tests,
however we still can not merge the ao and co tests into one file as
WITH (OIDS) is only supported by ao but not co.

When determining the locus for a LEFT or RIGHT JOIN, we can use the outer
side's distribution key as is. The EquivalenceClasses from the nullable
side are not of interest above the join, and the outer side's distribution
key can lead to better plans, because it can be made a Hashed locus,
rather than HashedOJ. A Hashed locus can be used for grouping, for
example, unlike a HashedOJ.

This buys back better plans for some INSERT and CTAS queries, that started
to need Redistribute Motions after the previous commit.
Reviewed-by: NMelanie Plageman <mplageman@pivotal.io>

There was some confusion on how NULLs are distributed, when CdbPathLocus
is of Hashed or HashedOJ type. The comment in cdbpathlocus.h suggested
that NULLs can be on any segment. But the rest of the code assumed that
that's true only for HashedOJ, and that for Hashed, all NULLs are stored
on a particular segment. There was a comment in cdbgroup.c that said "Or
would HashedOJ ok, too?"; the answer to that is "No!". Given the comment
in cdbpathlocus.h, I'm not suprised that the author was not very sure
about that. Clarify the comments in cdbpathlocus.h and cdbgroup.c on that.

There were a few cases where we got that actively wrong. repartitionPlan()
function is used to inject a Redistribute Motion into queries used for
CREATE TABLE AS and INSERT, if the "current" locus didn't match the target
table's policy. It did not check for HashedOJ. Because of that, if the
query contained FULL JOINs, NULL values might end up on all segments. Code
elsewhere, particularly in cdbgroup.c, assumes that all NULLs in a table
are stored on a single segment, identified by the cdbhash value of a NULL
datum. Fix that, by adding a check for HashedOJ in repartitionPlan(), and
forcing a Redistribute Motion.

CREATE TABLE AS had a similar problem, in the code to decide which
distribution key to use, if the user didn't specify DISTRIBUTED BY
explicitly. The default behaviour is to choose a distribution key that
matches the distribution of the query, so that we can avoid adding an
extra Redistribute Motion. After fixing repartitionPlan, there was no
correctness problem, but if we chose the key based on a HashedOJ locus,
there is no performance benefit because we'd need a Redistribute Motion
anyway. So modify the code that chooses the CTAS distribution key to
ignore HashedOJ.

While we're at it, refactor the code to choose the CTAS distribution key,
by moving it to a separate function. It had become ridiculously deeply
indented.

Fixes https://github.com/greenplum-db/gpdb/issues/6154, and adds tests.
Reviewed-by: NMelanie Plageman <mplageman@pivotal.io>

The case where some, but not all, of the query's distribution keys were
present in the result set, was not covered by any existing tests.

Per Paul Guo's observation.

This commit is the first step to refactor ATExecSetDistributedBy. Its
main purpose is to remove some dead code in this function and during
the process we find some helper functions can also be simplified so
the simplification is also in this commit.

According to MPP-7770, we should disable changing storage options for now.
It is ugly to just throw an error when encounter `appendonly` option but
without removing the code. In this commit remove all related logic.

Because of with clause can only contain reshuffle|reorganize, we only
new_rel_opts if the table itself is ao|aoco. No need to deduce it from with
clause.

We also remove the unnecessary checks at the start of this function. Because
These checks have been already done in the function `ATPrepCmd`.

Co-authored-by: Shuejie Zhang <shzhang@pivotal.io >

When the standby master is unavailable, the master will not block on commits
even though we enable synchronous replication. This is because we have a
Greenplum hack which checks if the WAL stream with the standby master is
valid. If the stream is invalid, the master will quickly skip the SyncRepWait
and continue on its commit.

Remove this hack in order to make Master/Standby and Primary/Mirror WAL
replication more similar.
Co-authored-by: NShaoqi Bai <sbai@pivotal.io>

Suppose t1 has numsegments=1 and t2 has numsegments=2, then below query
will have incorrect plan:

    explain (costs off) select * from t2 a join t2 b using(c2)
              union all select * from t1 c join t1 d using(c2);
                                   QUERY PLAN
    ------------------------------------------------------------------------
     Gather Motion 1:1  (slice3; segments: 1)
       ->  Append
             ->  Hash Join
                   Hash Cond: (a.c2 = b.c2)
                   ->  Redistribute Motion 2:2  (slice1; segments: 2)
                         Hash Key: a.c2
                         ->  Seq Scan on t2 a
                   ->  Hash
                         ->  Redistribute Motion 2:2  (slice2; segments: 2)
                               Hash Key: b.c2
                               ->  Seq Scan on t2 b
             ->  Hash Join
                   Hash Cond: (c.c2 = d.c2)
                   ->  Seq Scan on t1 c
                   ->  Hash
                         ->  Seq Scan on t1 d
     Optimizer: legacy query optimizer
    (17 rows)

slice2 has a 2:2 redistribute motion to slice3, however slice3 only has
1 segment, this is due to Append's numsegments is decided from the last
subpath.

To fix the issue we should use max numsegments of subpaths for Append.

The issue was already fixed in 39856768,
we are only adding tests for it now.

Introduced a new debugging extension gp_debug_numsegments to get / set
the default numsegments when creating tables.

gp_debug_get_create_table_default_numsegments() gets the default
numsegments.

gp_debug_set_create_table_default_numsegments(text) sets the default
numsegments in text format, valid values are:
- 'FULL': all the segments;
- 'RANDOM': pick a random set of segments each time;
- 'MINIMAL': the minimal set of segments;

gp_debug_set_create_table_default_numsegments(integer) sets the default
numsegments directly, valid range is [1, gp_num_contents_in_cluster].

gp_debug_reset_create_table_default_numsegments(text) or
gp_debug_reset_create_table_default_numsegments(integer) reset the
default numsegments to the specified value, and the value can be reused
later.

gp_debug_reset_create_table_default_numsegments() resets the default
numsegments to the value passed last time, if there is no previous call
to it the value is 'FULL'.

Refactored ICG test partial_table.sql to create partial tables with this
extension.

There is no restriction in the SQL specification regarding duplicate
column aliases in a CTE. Remove the specific check and align us with
how queries work in upstream. Also fix test fallout to match the new
behavior with slightly tweaked queries to keep output volume down.

A temp table is created during data reorganization, its numsegments must
be the same with the original table, otherwise some data will be lost
after the reorganization.
Reviewed-by: NDaniel Gustafsson <dgustafsson@pivotal.io>
Reviewed-by: NZhenghua Lyu <zlv@pivotal.io>
Reviewed-by: NShujie Zhang <shzhang@pivotal.io>

Commit 4c54c894 eliminates our divergence in deparsing filter
expressions mostly by adding parentheses. However only two out of four
expectfiles were updated, mostly likely because the author didn't run
alternate systems (i.e. macOS), . This leads to one of those
duh-it-fails-on-my-mac failures that can be easily fixed.

This commit brings the two expectfiles up-to-date.
Co-authored-by: NJesse Zhang <sbjesse@gmail.com>

Reviewed by Paul Guo, Heikki  Linnakangas 

The total number of rows in table, stored in pg_class.reltuples, was
calculated incorrectly. It was set to the number of rows in the sample,
not the (estimated?) total number of rows in the table. We didn't notice,
because most of the existing tests use small tables, so that the whole
table fit in the sample. Put back code like we used to have, for
collecting the totals.

This papers over the assertion failure we're seeing in the 'aocs' test in
the concourse pipeline, with ORCA, by changing the plan to one that doesn't
crash. It needs a proper fix, of course, but we're tracking that separately
as https://github.com/greenplum-db/gpdb/issues/6274.

The user-visible feature here is to speed up ANALYZE on heap tables, by
using the block-level sampling method from PostgreSQL, instead of the
scanning the whole table. This refactors the ANALYZE code, to make it
possible to call the upstream function to do the block-level sampling
again.

A secondary feature is that this enables the ANALYZE callback for Foreign
Data Wrappers, introduced in PostgreSQL 9.2. It was disabled in the 9.2
merge, because the function signature had been changed in GPDB, making
it cumbersome to call it. This patch reverts acquire-function's signature
to the same as in upstream, so the FDW callback now works again.

This also moves the logic to decide which rels to analyze, based on
optimizer_analyze_root_partition or optimizer_analyze_midlevel_partition
GUCs and the ROOTPARTITION option, wholly to get_rel_oids() in vacuum.c.
It was mostly done there already, but there were some warts in analyze.c.
None of the code in analyze.c should now treat partitions differently
from normal inherited tables, which helps to minimize the diff vs
upstream. (Except that the HLL code still heavily uses partition-related
functions. That's a TODO.)

Commit 4a174240 changed the hash method, which changed the data
distribution of data. It adjusted many test cases that were dependent on
the data distribution, but missed this one. This one isn't failing at the
moment, but it was clearly mean to look at the relfrozenxid of the segment
that it inserts all the data to. Change the value of the distribution key
so that all the data falls into segment 0 again.

The previous code makes UPDATE statement for root
and its children partitions when we reshuffle a partition
table. It not only involves redundant work but also will
lead to an error while reshuffling a two-level partition
table(because the mid-level partitions have no data).

The commit does the following work:

* Only make UPDATE statement for leaf partition or
   non-partition table.
* Refactor the reshuffle test cases. We remove the
   python udf code and use `gp_execute_on_server`
   and `gp_dist_random` to test replicated table.

Co-authored-by: Shujie Zhang shzhang@pivotal.io
Co-authored-by: Zhenghua Lyu zlv@pivotal.io

This commit adds the support and option of `mpp_execute 'MASTER | ANY |
ALL SEGMENTS'` for foreign tables.

MASTER is the default, FDW requests for data from master.

ANY, FDW requests for data from master or one any segment, depends on
which path costs less.

ALL SEGMENTS, FDW requests for data from all segments, wrappers need to
have a policy matching the segments to data.

For instance, file_fdw probes the mpp_execute vaule, then load different
files based on the segment number. But something like gpfdist on the
foreign side doesn't need this, which hands out a different slice of the
data to each request, all segments could request the same location.

Commit c20e5c4e added the gp_xml testsuite for GPDB XML tests in
order to not pollute the upstrean xml testsuite, it however failed to
add the alternative output for clusters compiled with out support for
XML.
Reviewed-by: NHeikki Linnakangas <hlinnakangas@pivotal.io>

This reverts commit fd602f46.
Co-authored-by: NDavid Kimura <dkimura@pivotal.io>
Co-authored-by: NAlexandra Wang <lewang@pivotal.io>

The xml type is not a default built-in type, but requires the server
to be compiled with --with-libxml. Since the type doesn't seem to do
much in this test, remove it to avoid failing tests in environments
not compiled with libxml support.

Adding an alternate output for builds without XML support would have
solved the issue too, but it would render most, if not all, of this
test useless.
Reviewed-by: NHeikki Linnakangas <hlinnakangas@pivotal.io>
Reviewed-by: NJesse Zhang <jzhang@pivotal.io>

When a subtransaction is aborted, a backend calls AbortSubTransaction(),
instead of AbortTransaction(). Add a second call to CancelMyReaders() to
AbortSubTransaction to cover these cases.
Co-authored-by: NAsim R P <apraveen@pivotal.io>
Co-authored-by: NTaylor Vesely <tvesely@pivotal.io>

A proper fix to ensure that a QE writer signals QE readers before
aborting a transaction is made in PR #6089.  The temporary workaround
is no longer necessary.

This reverts commit b6dd73a4.
Co-authored-by: NAsim R P <apraveen@pivotal.io>