From 21975923277988683381d0610f019d2cd4516298 Mon Sep 17 00:00:00 2001
From: Greg Nancarrow <gregn4422@gmail.com>
Date: Fri, 5 Mar 2021 20:54:50 +1100
Subject: [PATCH v22 2/6] Parallel SELECT for "INSERT INTO ... SELECT ..." -
 basic tests and documentation updates.

---
 doc/src/sgml/parallel.sgml                    |   4 +-
 src/test/regress/expected/insert_parallel.out | 538 ++++++++++++++++++
 src/test/regress/parallel_schedule            |   1 +
 src/test/regress/serial_schedule              |   1 +
 src/test/regress/sql/insert_parallel.sql      | 337 +++++++++++
 5 files changed, 880 insertions(+), 1 deletion(-)
 create mode 100644 src/test/regress/expected/insert_parallel.out
 create mode 100644 src/test/regress/sql/insert_parallel.sql

diff --git a/doc/src/sgml/parallel.sgml b/doc/src/sgml/parallel.sgml
index c81abff48d..cec1329e25 100644
--- a/doc/src/sgml/parallel.sgml
+++ b/doc/src/sgml/parallel.sgml
@@ -146,7 +146,9 @@ EXPLAIN SELECT * FROM pgbench_accounts WHERE filler LIKE '%x%';
         a CTE, no parallel plans for that query will be generated.  As an
         exception, the commands <literal>CREATE TABLE ... AS</literal>, <literal>SELECT
         INTO</literal>, and <literal>CREATE MATERIALIZED VIEW</literal> which create a new
-        table and populate it can use a parallel plan.
+        table and populate it can use a parallel plan. Another exception is the command
+        <literal>INSERT INTO ... SELECT ...</literal> which can use a parallel plan for
+        the underlying <literal>SELECT</literal> part of the query.
       </para>
     </listitem>
 
diff --git a/src/test/regress/expected/insert_parallel.out b/src/test/regress/expected/insert_parallel.out
new file mode 100644
index 0000000000..ef5615cb4b
--- /dev/null
+++ b/src/test/regress/expected/insert_parallel.out
@@ -0,0 +1,538 @@
+--
+-- PARALLEL
+--
+--
+-- START: setup some tables and data needed by the tests.
+--
+-- Setup - index expressions test
+-- For testing purposes, we'll mark this function as parallel-unsafe
+create or replace function fullname_parallel_unsafe(f text, l text) returns text as $$
+    begin
+        return f || l;
+    end;
+$$ language plpgsql immutable parallel unsafe;
+create or replace function fullname_parallel_restricted(f text, l text) returns text as $$
+    begin
+        return f || l;
+    end;
+$$ language plpgsql immutable parallel restricted;
+create table names(index int, first_name text, last_name text);
+create table names2(index int, first_name text, last_name text);
+create index names2_fullname_idx on names2 (fullname_parallel_unsafe(first_name, last_name));
+create table names4(index int, first_name text, last_name text);
+create index names4_fullname_idx on names4 (fullname_parallel_restricted(first_name, last_name));
+insert into names values
+	(1, 'albert', 'einstein'),
+	(2, 'niels', 'bohr'),
+	(3, 'erwin', 'schrodinger'),
+	(4, 'leonhard', 'euler'),
+	(5, 'stephen', 'hawking'),
+	(6, 'isaac', 'newton'),
+	(7, 'alan', 'turing'),
+	(8, 'richard', 'feynman');
+-- Setup - column default tests
+create or replace function bdefault_unsafe ()
+returns int language plpgsql parallel unsafe as $$
+begin
+	RETURN 5;
+end $$;
+create or replace function cdefault_restricted ()
+returns int language plpgsql parallel restricted as $$
+begin
+	RETURN 10;
+end $$;
+create or replace function ddefault_safe ()
+returns int language plpgsql parallel safe as $$
+begin
+	RETURN 20;
+end $$;
+create table testdef(a int, b int default bdefault_unsafe(), c int default cdefault_restricted(), d int default ddefault_safe());
+create table test_data(a int);
+insert into test_data select * from generate_series(1,10);
+--
+-- END: setup some tables and data needed by the tests.
+--
+-- Serializable isolation would disable parallel query, so explicitly use an
+-- arbitrary other level.
+begin isolation level repeatable read;
+-- encourage use of parallel plans
+set parallel_setup_cost=0;
+set parallel_tuple_cost=0;
+set min_parallel_table_scan_size=0;
+set max_parallel_workers_per_gather=4;
+create table para_insert_p1 (
+	unique1		int4	PRIMARY KEY,
+	stringu1	name
+);
+create table para_insert_f1 (
+	unique1		int4	REFERENCES para_insert_p1(unique1),
+	stringu1	name
+);
+--
+-- Test INSERT with underlying query.
+-- (should create plan with parallel SELECT, Gather parent node)
+--
+explain (costs off) insert into para_insert_p1 select unique1, stringu1 from tenk1;
+               QUERY PLAN               
+----------------------------------------
+ Insert on para_insert_p1
+   ->  Gather
+         Workers Planned: 4
+         ->  Parallel Seq Scan on tenk1
+(4 rows)
+
+insert into para_insert_p1 select unique1, stringu1 from tenk1;
+-- select some values to verify that the parallel insert worked
+select count(*), sum(unique1) from para_insert_p1;
+ count |   sum    
+-------+----------
+ 10000 | 49995000
+(1 row)
+
+-- verify that the same transaction has been used by all parallel workers
+select count(*) from (select distinct cmin,xmin from para_insert_p1) as dt;
+ count 
+-------
+     1
+(1 row)
+
+--
+-- Test INSERT with ordered underlying query.
+-- (should create plan with parallel SELECT, GatherMerge parent node)
+--
+truncate para_insert_p1 cascade;
+NOTICE:  truncate cascades to table "para_insert_f1"
+explain (costs off) insert into para_insert_p1 select unique1, stringu1 from tenk1 order by unique1;
+                  QUERY PLAN                  
+----------------------------------------------
+ Insert on para_insert_p1
+   ->  Gather Merge
+         Workers Planned: 4
+         ->  Sort
+               Sort Key: tenk1.unique1
+               ->  Parallel Seq Scan on tenk1
+(6 rows)
+
+insert into para_insert_p1 select unique1, stringu1 from tenk1 order by unique1;
+-- select some values to verify that the parallel insert worked
+select count(*), sum(unique1) from para_insert_p1;
+ count |   sum    
+-------+----------
+ 10000 | 49995000
+(1 row)
+
+-- verify that the same transaction has been used by all parallel workers
+select count(*) from (select distinct cmin,xmin from para_insert_p1) as dt;
+ count 
+-------
+     1
+(1 row)
+
+--
+-- Test INSERT with RETURNING clause.
+-- (should create plan with parallel SELECT, Gather parent node)
+--
+create table test_data1(like test_data);
+explain (costs off) insert into test_data1 select * from test_data where a = 10 returning a as data;
+                 QUERY PLAN                 
+--------------------------------------------
+ Insert on test_data1
+   ->  Gather
+         Workers Planned: 3
+         ->  Parallel Seq Scan on test_data
+               Filter: (a = 10)
+(5 rows)
+
+insert into test_data1 select * from test_data where a = 10 returning a as data;
+ data 
+------
+   10
+(1 row)
+
+--
+-- Test INSERT into a table with a foreign key.
+-- (Insert into a table with a foreign key is parallel-restricted,
+--  as doing this in a parallel worker would create a new commandId
+--  and within a worker this is not currently supported)
+--
+explain (costs off) insert into para_insert_f1 select unique1, stringu1 from tenk1;
+               QUERY PLAN               
+----------------------------------------
+ Insert on para_insert_f1
+   ->  Gather
+         Workers Planned: 4
+         ->  Parallel Seq Scan on tenk1
+(4 rows)
+
+insert into para_insert_f1 select unique1, stringu1 from tenk1;
+-- select some values to verify that the insert worked
+select count(*), sum(unique1) from para_insert_f1;
+ count |   sum    
+-------+----------
+ 10000 | 49995000
+(1 row)
+
+--
+-- Test INSERT with ON CONFLICT ... DO UPDATE ...
+-- (should not create a parallel plan)
+--
+create table test_conflict_table(id serial primary key, somedata int);
+explain (costs off) insert into test_conflict_table(id, somedata) select a, a from test_data;
+                 QUERY PLAN                 
+--------------------------------------------
+ Insert on test_conflict_table
+   ->  Gather
+         Workers Planned: 3
+         ->  Parallel Seq Scan on test_data
+(4 rows)
+
+insert into test_conflict_table(id, somedata) select a, a from test_data;
+explain (costs off) insert into test_conflict_table(id, somedata) select a, a from test_data ON CONFLICT(id) DO UPDATE SET somedata = EXCLUDED.somedata + 1;
+                      QUERY PLAN                      
+------------------------------------------------------
+ Insert on test_conflict_table
+   Conflict Resolution: UPDATE
+   Conflict Arbiter Indexes: test_conflict_table_pkey
+   ->  Seq Scan on test_data
+(4 rows)
+
+--
+-- Test INSERT with parallel-unsafe index expression
+-- (should not create a parallel plan)
+--
+explain (costs off) insert into names2 select * from names;
+       QUERY PLAN        
+-------------------------
+ Insert on names2
+   ->  Seq Scan on names
+(2 rows)
+
+--
+-- Test INSERT with parallel-restricted index expression
+-- (should create a parallel plan)
+--
+explain (costs off) insert into names4 select * from names;
+               QUERY PLAN               
+----------------------------------------
+ Insert on names4
+   ->  Gather
+         Workers Planned: 3
+         ->  Parallel Seq Scan on names
+(4 rows)
+
+--
+-- Test INSERT with underlying query - and RETURNING (no projection)
+-- (should create a parallel plan; parallel SELECT)
+--
+create table names5 (like names);
+explain (costs off) insert into names5 select * from names returning *;
+               QUERY PLAN               
+----------------------------------------
+ Insert on names5
+   ->  Gather
+         Workers Planned: 3
+         ->  Parallel Seq Scan on names
+(4 rows)
+
+--
+-- Test INSERT with underlying ordered query - and RETURNING (no projection)
+-- (should create a parallel plan; parallel SELECT)
+--
+create table names6 (like names);
+explain (costs off) insert into names6 select * from names order by last_name returning *;
+                  QUERY PLAN                  
+----------------------------------------------
+ Insert on names6
+   ->  Gather Merge
+         Workers Planned: 3
+         ->  Sort
+               Sort Key: names.last_name
+               ->  Parallel Seq Scan on names
+(6 rows)
+
+insert into names6 select * from names order by last_name returning *;
+ index | first_name |  last_name  
+-------+------------+-------------
+     2 | niels      | bohr
+     1 | albert     | einstein
+     4 | leonhard   | euler
+     8 | richard    | feynman
+     5 | stephen    | hawking
+     6 | isaac      | newton
+     3 | erwin      | schrodinger
+     7 | alan       | turing
+(8 rows)
+
+--
+-- Test INSERT with underlying ordered query - and RETURNING (with projection)
+-- (should create a parallel plan; parallel SELECT)
+--
+create table names7 (like names);
+explain (costs off) insert into names7 select * from names order by last_name returning last_name || ', ' || first_name as last_name_then_first_name;
+                  QUERY PLAN                  
+----------------------------------------------
+ Insert on names7
+   ->  Gather Merge
+         Workers Planned: 3
+         ->  Sort
+               Sort Key: names.last_name
+               ->  Parallel Seq Scan on names
+(6 rows)
+
+insert into names7 select * from names order by last_name returning last_name || ', ' || first_name as last_name_then_first_name;
+ last_name_then_first_name 
+---------------------------
+ bohr, niels
+ einstein, albert
+ euler, leonhard
+ feynman, richard
+ hawking, stephen
+ newton, isaac
+ schrodinger, erwin
+ turing, alan
+(8 rows)
+
+--
+-- Test INSERT into temporary table with underlying query.
+-- (Insert into a temp table is parallel-restricted;
+-- should create a parallel plan; parallel SELECT)
+--
+create temporary table temp_names (like names);
+explain (costs off) insert into temp_names select * from names;
+               QUERY PLAN               
+----------------------------------------
+ Insert on temp_names
+   ->  Gather
+         Workers Planned: 3
+         ->  Parallel Seq Scan on names
+(4 rows)
+
+insert into temp_names select * from names;
+--
+-- Test INSERT with column defaults
+--
+--
+--
+-- Parallel unsafe column default, should not use a parallel plan
+--
+explain (costs off) insert into testdef(a,c,d) select a,a*4,a*8 from test_data;
+         QUERY PLAN          
+-----------------------------
+ Insert on testdef
+   ->  Seq Scan on test_data
+(2 rows)
+
+--
+-- Parallel restricted column default, should use parallel SELECT
+--
+explain (costs off) insert into testdef(a,b,d) select a,a*2,a*8 from test_data;
+                 QUERY PLAN                 
+--------------------------------------------
+ Insert on testdef
+   ->  Gather
+         Workers Planned: 3
+         ->  Parallel Seq Scan on test_data
+(4 rows)
+
+insert into testdef(a,b,d) select a,a*2,a*8 from test_data;
+select * from testdef order by a;
+ a  | b  | c  | d  
+----+----+----+----
+  1 |  2 | 10 |  8
+  2 |  4 | 10 | 16
+  3 |  6 | 10 | 24
+  4 |  8 | 10 | 32
+  5 | 10 | 10 | 40
+  6 | 12 | 10 | 48
+  7 | 14 | 10 | 56
+  8 | 16 | 10 | 64
+  9 | 18 | 10 | 72
+ 10 | 20 | 10 | 80
+(10 rows)
+
+truncate testdef;
+--
+-- Parallel restricted and unsafe column defaults, should not use a parallel plan
+--
+explain (costs off) insert into testdef(a,d) select a,a*8 from test_data;
+         QUERY PLAN          
+-----------------------------
+ Insert on testdef
+   ->  Seq Scan on test_data
+(2 rows)
+
+--
+-- Test INSERT into partition with underlying query.
+--
+create table parttable1 (a int, b name) partition by range (a);
+create table parttable1_1 partition of parttable1 for values from (0) to (5000);
+create table parttable1_2 partition of parttable1 for values from (5000) to (10000);
+explain (costs off) insert into parttable1 select unique1,stringu1 from tenk1;
+               QUERY PLAN               
+----------------------------------------
+ Insert on parttable1
+   ->  Gather
+         Workers Planned: 4
+         ->  Parallel Seq Scan on tenk1
+(4 rows)
+
+insert into parttable1 select unique1,stringu1 from tenk1;
+select count(*) from parttable1_1;
+ count 
+-------
+  5000
+(1 row)
+
+select count(*) from parttable1_2;
+ count 
+-------
+  5000
+(1 row)
+
+--
+-- Test INSERT into table with parallel-unsafe check constraint
+-- (should not create a parallel plan)
+--
+create or replace function check_b_unsafe(b name) returns boolean as $$
+    begin
+        return (b <> 'XXXXXX');
+    end;
+$$ language plpgsql parallel unsafe;
+create table table_check_b(a int4, b name check (check_b_unsafe(b)), c name);
+explain (costs off) insert into table_check_b(a,b,c) select unique1, unique2, stringu1 from tenk1;
+       QUERY PLAN        
+-------------------------
+ Insert on table_check_b
+   ->  Seq Scan on tenk1
+(2 rows)
+
+--
+-- Test INSERT into table with parallel-safe after stmt-level triggers
+-- (should create a parallel SELECT plan;
+--  stmt-level before+after triggers should fire)
+--
+create table names_with_safe_trigger (like names);
+create or replace function insert_after_trigger_safe() returns trigger as $$
+    begin
+        raise notice 'hello from insert_after_trigger_safe';
+		return new;
+    end;
+$$ language plpgsql parallel safe;
+create trigger insert_after_trigger_safe after insert on names_with_safe_trigger
+    for each statement execute procedure insert_after_trigger_safe();
+explain (costs off) insert into names_with_safe_trigger select * from names;
+               QUERY PLAN               
+----------------------------------------
+ Insert on names_with_safe_trigger
+   ->  Gather
+         Workers Planned: 3
+         ->  Parallel Seq Scan on names
+(4 rows)
+
+insert into names_with_safe_trigger select * from names;
+NOTICE:  hello from insert_after_trigger_safe
+--
+-- Test INSERT into table with parallel-unsafe after stmt-level triggers
+-- (should not create a parallel plan;
+--  stmt-level before+after triggers should fire)
+--
+create table names_with_unsafe_trigger (like names);
+create or replace function insert_after_trigger_unsafe() returns trigger as $$
+    begin
+        raise notice 'hello from insert_after_trigger_unsafe';
+		return new;
+    end;
+$$ language plpgsql parallel unsafe;
+create trigger insert_after_trigger_unsafe after insert on names_with_unsafe_trigger
+    for each statement execute procedure insert_after_trigger_unsafe();
+explain (costs off) insert into names_with_unsafe_trigger select * from names;
+             QUERY PLAN              
+-------------------------------------
+ Insert on names_with_unsafe_trigger
+   ->  Seq Scan on names
+(2 rows)
+
+insert into names_with_unsafe_trigger select * from names;
+NOTICE:  hello from insert_after_trigger_unsafe
+--
+-- Test INSERT into partition with parallel-unsafe trigger
+-- (should not create a parallel plan)
+--
+create table part_unsafe_trigger (a int4, b name) partition by range (a);
+create table part_unsafe_trigger_1 partition of part_unsafe_trigger for values from (0) to (5000);
+create table part_unsafe_trigger_2 partition of part_unsafe_trigger for values from (5000) to (10000);
+create trigger part_insert_after_trigger_unsafe after insert on part_unsafe_trigger_1
+    for each statement execute procedure insert_after_trigger_unsafe();
+explain (costs off) insert into part_unsafe_trigger select unique1, stringu1 from tenk1;
+          QUERY PLAN           
+-------------------------------
+ Insert on part_unsafe_trigger
+   ->  Seq Scan on tenk1
+(2 rows)
+
+--
+-- Test that parallel-safety-related changes to partitions are detected and
+-- plan cache invalidation is working correctly.
+--
+create table rp (a int) partition by range (a);
+create table rp1 partition of rp for values from (minvalue) to (0);
+create table rp2 partition of rp for values from (0) to (maxvalue);
+create table foo (a) as select unique1 from tenk1;
+prepare q as insert into rp select * from foo where a%2 = 0;
+-- should create a parallel plan
+explain (costs off) execute q;
+              QUERY PLAN              
+--------------------------------------
+ Insert on rp
+   ->  Gather
+         Workers Planned: 4
+         ->  Parallel Seq Scan on foo
+               Filter: ((a % 2) = 0)
+(5 rows)
+
+create or replace function make_table_bar () returns trigger language
+plpgsql as $$ begin create table bar(); return null; end; $$ parallel unsafe;
+create trigger ai_rp2 after insert on rp2 for each row execute
+function make_table_bar();
+-- should create a non-parallel plan
+explain (costs off) execute q;
+          QUERY PLAN           
+-------------------------------
+ Insert on rp
+   ->  Seq Scan on foo
+         Filter: ((a % 2) = 0)
+(3 rows)
+
+--
+-- Test INSERT into table having a DOMAIN column with a CHECK constraint
+--
+create function sql_is_distinct_from_u(anyelement, anyelement)
+returns boolean language sql parallel unsafe
+as 'select $1 is distinct from $2 limit 1';
+create domain inotnull_u int
+  check (sql_is_distinct_from_u(value, null));
+create table dom_table_u (x inotnull_u, y int);
+-- Test INSERT into table having a DOMAIN column with parallel-unsafe CHECK constraint
+explain (costs off) insert into dom_table_u select unique1, unique2 from tenk1;
+       QUERY PLAN        
+-------------------------
+ Insert on dom_table_u
+   ->  Seq Scan on tenk1
+(2 rows)
+
+rollback;
+--
+-- Clean up anything not created in the transaction
+--
+drop table names;
+drop index names2_fullname_idx;
+drop table names2;
+drop index names4_fullname_idx;
+drop table names4;
+drop table testdef;
+drop table test_data;
+drop function bdefault_unsafe;
+drop function cdefault_restricted;
+drop function ddefault_safe;
+drop function fullname_parallel_unsafe;
+drop function fullname_parallel_restricted;
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index c77b0d7342..e280198b17 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -90,6 +90,7 @@ test: rules psql psql_crosstab amutils stats_ext collate.linux.utf8
 # run by itself so it can run parallel workers
 test: select_parallel
 test: write_parallel
+test: insert_parallel
 
 # no relation related tests can be put in this group
 test: publication subscription
diff --git a/src/test/regress/serial_schedule b/src/test/regress/serial_schedule
index 0264a97324..6a57e889a1 100644
--- a/src/test/regress/serial_schedule
+++ b/src/test/regress/serial_schedule
@@ -148,6 +148,7 @@ test: stats_ext
 test: collate.linux.utf8
 test: select_parallel
 test: write_parallel
+test: insert_parallel
 test: publication
 test: subscription
 test: select_views
diff --git a/src/test/regress/sql/insert_parallel.sql b/src/test/regress/sql/insert_parallel.sql
new file mode 100644
index 0000000000..8bea0dc02f
--- /dev/null
+++ b/src/test/regress/sql/insert_parallel.sql
@@ -0,0 +1,337 @@
+--
+-- PARALLEL
+--
+
+--
+-- START: setup some tables and data needed by the tests.
+--
+
+-- Setup - index expressions test
+
+-- For testing purposes, we'll mark this function as parallel-unsafe
+create or replace function fullname_parallel_unsafe(f text, l text) returns text as $$
+    begin
+        return f || l;
+    end;
+$$ language plpgsql immutable parallel unsafe;
+
+create or replace function fullname_parallel_restricted(f text, l text) returns text as $$
+    begin
+        return f || l;
+    end;
+$$ language plpgsql immutable parallel restricted;
+
+create table names(index int, first_name text, last_name text);
+create table names2(index int, first_name text, last_name text);
+create index names2_fullname_idx on names2 (fullname_parallel_unsafe(first_name, last_name));
+create table names4(index int, first_name text, last_name text);
+create index names4_fullname_idx on names4 (fullname_parallel_restricted(first_name, last_name));
+
+insert into names values
+	(1, 'albert', 'einstein'),
+	(2, 'niels', 'bohr'),
+	(3, 'erwin', 'schrodinger'),
+	(4, 'leonhard', 'euler'),
+	(5, 'stephen', 'hawking'),
+	(6, 'isaac', 'newton'),
+	(7, 'alan', 'turing'),
+	(8, 'richard', 'feynman');
+
+-- Setup - column default tests
+
+create or replace function bdefault_unsafe ()
+returns int language plpgsql parallel unsafe as $$
+begin
+	RETURN 5;
+end $$;
+
+create or replace function cdefault_restricted ()
+returns int language plpgsql parallel restricted as $$
+begin
+	RETURN 10;
+end $$;
+
+create or replace function ddefault_safe ()
+returns int language plpgsql parallel safe as $$
+begin
+	RETURN 20;
+end $$;
+
+create table testdef(a int, b int default bdefault_unsafe(), c int default cdefault_restricted(), d int default ddefault_safe());
+
+create table test_data(a int);
+insert into test_data select * from generate_series(1,10);
+
+--
+-- END: setup some tables and data needed by the tests.
+--
+
+-- Serializable isolation would disable parallel query, so explicitly use an
+-- arbitrary other level.
+begin isolation level repeatable read;
+
+-- encourage use of parallel plans
+set parallel_setup_cost=0;
+set parallel_tuple_cost=0;
+set min_parallel_table_scan_size=0;
+set max_parallel_workers_per_gather=4;
+
+create table para_insert_p1 (
+	unique1		int4	PRIMARY KEY,
+	stringu1	name
+);
+
+create table para_insert_f1 (
+	unique1		int4	REFERENCES para_insert_p1(unique1),
+	stringu1	name
+);
+
+
+--
+-- Test INSERT with underlying query.
+-- (should create plan with parallel SELECT, Gather parent node)
+--
+explain (costs off) insert into para_insert_p1 select unique1, stringu1 from tenk1;
+insert into para_insert_p1 select unique1, stringu1 from tenk1;
+-- select some values to verify that the parallel insert worked
+select count(*), sum(unique1) from para_insert_p1;
+-- verify that the same transaction has been used by all parallel workers
+select count(*) from (select distinct cmin,xmin from para_insert_p1) as dt;
+
+--
+-- Test INSERT with ordered underlying query.
+-- (should create plan with parallel SELECT, GatherMerge parent node)
+--
+truncate para_insert_p1 cascade;
+explain (costs off) insert into para_insert_p1 select unique1, stringu1 from tenk1 order by unique1;
+insert into para_insert_p1 select unique1, stringu1 from tenk1 order by unique1;
+-- select some values to verify that the parallel insert worked
+select count(*), sum(unique1) from para_insert_p1;
+-- verify that the same transaction has been used by all parallel workers
+select count(*) from (select distinct cmin,xmin from para_insert_p1) as dt;
+
+--
+-- Test INSERT with RETURNING clause.
+-- (should create plan with parallel SELECT, Gather parent node)
+--
+create table test_data1(like test_data);
+explain (costs off) insert into test_data1 select * from test_data where a = 10 returning a as data;
+insert into test_data1 select * from test_data where a = 10 returning a as data;
+
+--
+-- Test INSERT into a table with a foreign key.
+-- (Insert into a table with a foreign key is parallel-restricted,
+--  as doing this in a parallel worker would create a new commandId
+--  and within a worker this is not currently supported)
+--
+explain (costs off) insert into para_insert_f1 select unique1, stringu1 from tenk1;
+insert into para_insert_f1 select unique1, stringu1 from tenk1;
+-- select some values to verify that the insert worked
+select count(*), sum(unique1) from para_insert_f1;
+
+--
+-- Test INSERT with ON CONFLICT ... DO UPDATE ...
+-- (should not create a parallel plan)
+--
+create table test_conflict_table(id serial primary key, somedata int);
+explain (costs off) insert into test_conflict_table(id, somedata) select a, a from test_data;
+insert into test_conflict_table(id, somedata) select a, a from test_data;
+explain (costs off) insert into test_conflict_table(id, somedata) select a, a from test_data ON CONFLICT(id) DO UPDATE SET somedata = EXCLUDED.somedata + 1;
+
+
+--
+-- Test INSERT with parallel-unsafe index expression
+-- (should not create a parallel plan)
+--
+explain (costs off) insert into names2 select * from names;
+
+--
+-- Test INSERT with parallel-restricted index expression
+-- (should create a parallel plan)
+--
+explain (costs off) insert into names4 select * from names;
+
+--
+-- Test INSERT with underlying query - and RETURNING (no projection)
+-- (should create a parallel plan; parallel SELECT)
+--
+create table names5 (like names);
+explain (costs off) insert into names5 select * from names returning *;
+
+--
+-- Test INSERT with underlying ordered query - and RETURNING (no projection)
+-- (should create a parallel plan; parallel SELECT)
+--
+create table names6 (like names);
+explain (costs off) insert into names6 select * from names order by last_name returning *;
+insert into names6 select * from names order by last_name returning *;
+
+--
+-- Test INSERT with underlying ordered query - and RETURNING (with projection)
+-- (should create a parallel plan; parallel SELECT)
+--
+create table names7 (like names);
+explain (costs off) insert into names7 select * from names order by last_name returning last_name || ', ' || first_name as last_name_then_first_name;
+insert into names7 select * from names order by last_name returning last_name || ', ' || first_name as last_name_then_first_name;
+
+
+--
+-- Test INSERT into temporary table with underlying query.
+-- (Insert into a temp table is parallel-restricted;
+-- should create a parallel plan; parallel SELECT)
+--
+create temporary table temp_names (like names);
+explain (costs off) insert into temp_names select * from names;
+insert into temp_names select * from names;
+
+--
+-- Test INSERT with column defaults
+--
+--
+
+--
+-- Parallel unsafe column default, should not use a parallel plan
+--
+explain (costs off) insert into testdef(a,c,d) select a,a*4,a*8 from test_data;
+
+--
+-- Parallel restricted column default, should use parallel SELECT
+--
+explain (costs off) insert into testdef(a,b,d) select a,a*2,a*8 from test_data;
+insert into testdef(a,b,d) select a,a*2,a*8 from test_data;
+select * from testdef order by a;
+truncate testdef;
+
+--
+-- Parallel restricted and unsafe column defaults, should not use a parallel plan
+--
+explain (costs off) insert into testdef(a,d) select a,a*8 from test_data;
+
+--
+-- Test INSERT into partition with underlying query.
+--
+create table parttable1 (a int, b name) partition by range (a);
+create table parttable1_1 partition of parttable1 for values from (0) to (5000);
+create table parttable1_2 partition of parttable1 for values from (5000) to (10000);
+
+explain (costs off) insert into parttable1 select unique1,stringu1 from tenk1;
+insert into parttable1 select unique1,stringu1 from tenk1;
+select count(*) from parttable1_1;
+select count(*) from parttable1_2;
+
+--
+-- Test INSERT into table with parallel-unsafe check constraint
+-- (should not create a parallel plan)
+--
+create or replace function check_b_unsafe(b name) returns boolean as $$
+    begin
+        return (b <> 'XXXXXX');
+    end;
+$$ language plpgsql parallel unsafe;
+
+create table table_check_b(a int4, b name check (check_b_unsafe(b)), c name);
+explain (costs off) insert into table_check_b(a,b,c) select unique1, unique2, stringu1 from tenk1;
+
+--
+-- Test INSERT into table with parallel-safe after stmt-level triggers
+-- (should create a parallel SELECT plan;
+--  stmt-level before+after triggers should fire)
+--
+create table names_with_safe_trigger (like names);
+create or replace function insert_after_trigger_safe() returns trigger as $$
+    begin
+        raise notice 'hello from insert_after_trigger_safe';
+		return new;
+    end;
+$$ language plpgsql parallel safe;
+create trigger insert_after_trigger_safe after insert on names_with_safe_trigger
+    for each statement execute procedure insert_after_trigger_safe();
+explain (costs off) insert into names_with_safe_trigger select * from names;
+insert into names_with_safe_trigger select * from names;
+
+--
+-- Test INSERT into table with parallel-unsafe after stmt-level triggers
+-- (should not create a parallel plan;
+--  stmt-level before+after triggers should fire)
+--
+create table names_with_unsafe_trigger (like names);
+create or replace function insert_after_trigger_unsafe() returns trigger as $$
+    begin
+        raise notice 'hello from insert_after_trigger_unsafe';
+		return new;
+    end;
+$$ language plpgsql parallel unsafe;
+create trigger insert_after_trigger_unsafe after insert on names_with_unsafe_trigger
+    for each statement execute procedure insert_after_trigger_unsafe();
+explain (costs off) insert into names_with_unsafe_trigger select * from names;
+insert into names_with_unsafe_trigger select * from names;
+
+--
+-- Test INSERT into partition with parallel-unsafe trigger
+-- (should not create a parallel plan)
+--
+
+create table part_unsafe_trigger (a int4, b name) partition by range (a);
+create table part_unsafe_trigger_1 partition of part_unsafe_trigger for values from (0) to (5000);
+create table part_unsafe_trigger_2 partition of part_unsafe_trigger for values from (5000) to (10000);
+create trigger part_insert_after_trigger_unsafe after insert on part_unsafe_trigger_1
+    for each statement execute procedure insert_after_trigger_unsafe();
+
+explain (costs off) insert into part_unsafe_trigger select unique1, stringu1 from tenk1;
+
+--
+-- Test that parallel-safety-related changes to partitions are detected and
+-- plan cache invalidation is working correctly.
+--
+
+create table rp (a int) partition by range (a);
+create table rp1 partition of rp for values from (minvalue) to (0);
+create table rp2 partition of rp for values from (0) to (maxvalue);
+create table foo (a) as select unique1 from tenk1;
+prepare q as insert into rp select * from foo where a%2 = 0;
+-- should create a parallel plan
+explain (costs off) execute q;
+
+create or replace function make_table_bar () returns trigger language
+plpgsql as $$ begin create table bar(); return null; end; $$ parallel unsafe;
+create trigger ai_rp2 after insert on rp2 for each row execute
+function make_table_bar();
+-- should create a non-parallel plan
+explain (costs off) execute q;
+
+--
+-- Test INSERT into table having a DOMAIN column with a CHECK constraint
+--
+create function sql_is_distinct_from_u(anyelement, anyelement)
+returns boolean language sql parallel unsafe
+as 'select $1 is distinct from $2 limit 1';
+
+create domain inotnull_u int
+  check (sql_is_distinct_from_u(value, null));
+
+create table dom_table_u (x inotnull_u, y int);
+
+
+-- Test INSERT into table having a DOMAIN column with parallel-unsafe CHECK constraint
+explain (costs off) insert into dom_table_u select unique1, unique2 from tenk1;
+
+
+rollback;
+
+--
+-- Clean up anything not created in the transaction
+--
+
+drop table names;
+drop index names2_fullname_idx;
+drop table names2;
+drop index names4_fullname_idx;
+drop table names4;
+drop table testdef;
+drop table test_data;
+
+drop function bdefault_unsafe;
+drop function cdefault_restricted;
+drop function ddefault_safe;
+drop function fullname_parallel_unsafe;
+drop function fullname_parallel_restricted;
-- 
2.27.0

