Columnar: Fix ALTER TABLE ... ADD COLUMN.

src/backend/columnar/cstore_tableam.c

@@ -112,10 +112,9 @@ static Datum * detoast_values(TupleDesc tupleDesc, Datum *orig_values, bool *isn
 static TupleTableSlotOps TTSOpsColumnar;
 
 static List *
-RelationColumnList(Relation rel)
+RelationColumnList(TupleDesc tupdesc)
 {
 	List *columnList = NIL;
-	TupleDesc tupdesc = RelationGetDescr(rel);
 
 	for (int i = 0; i < tupdesc->natts; i++)
 	{
@@ -234,7 +233,7 @@ static TableReadState *
 init_columnar_read_state(Relation relation, TupleDesc tupdesc, Bitmapset *attr_needed,
 						 List *scanQual)
 {
-	List *columnList = RelationColumnList(relation);
+	List *columnList = RelationColumnList(tupdesc);
 	ListCell *columnCell = NULL;
 
 	List *neededColumnList = NIL;
@@ -641,7 +640,7 @@ columnar_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 													 targetDesc);
 
 	TableReadState *readState = ColumnarBeginRead(OldHeap, sourceDesc,
-												  RelationColumnList(OldHeap), NULL);
+												  RelationColumnList(sourceDesc), NULL);
 
 	Datum *values = palloc0(sourceDesc->natts * sizeof(Datum));
 	bool *nulls = palloc0(sourceDesc->natts * sizeof(bool));

src/test/regress/expected/am_alter.out

@@ -1,6 +1,8 @@
 --
--- Testing ALTER TABLE on cstore_fdw tables.
+-- Testing ALTER TABLE on columnar tables.
 --
+CREATE SCHEMA columnar_alter;
+SET search_path tO columnar_alter, public;
 CREATE TABLE test_alter_table (a int, b int, c int) USING columnar;
 WITH sample_data AS (VALUES
     (1, 2, 3),
@@ -171,3 +173,72 @@ ALTER TABLE test_alter_table ALTER COLUMN j TYPE int;
 ALTER TABLE test_alter_table ALTER COLUMN k TYPE varchar(20);
 ALTER TABLE test_alter_table ALTER COLUMN k TYPE text;
 DROP TABLE test_alter_table;
+-- https://github.com/citusdata/citus/issues/4602
+create domain str_domain as text not null;
+create table domain_test (a int, b int) using columnar;
+insert into domain_test values (1, 2);
+insert into domain_test values (1, 2);
+-- the following should error out since the domain is not nullable
+alter table domain_test add column c str_domain;
+ERROR:  domain str_domain does not allow null values
+-- but this should succeed
+alter table domain_test add column c str_domain DEFAULT 'x';
+SELECT * FROM domain_test;
+ a | b | c
+---------------------------------------------------------------------
+ 1 | 2 | x
+ 1 | 2 | x
+(2 rows)
+
+set default_table_access_method TO 'columnar';
+CREATE TABLE has_volatile AS
+SELECT * FROM generate_series(1,10) id;
+ALTER TABLE has_volatile ADD col4 int DEFAULT (random() * 10000)::int;
+SELECT id, col4 < 10000 FROM has_volatile ORDER BY id;
+ id | ?column?
+---------------------------------------------------------------------
+  1 | t
+  2 | t
+  3 | t
+  4 | t
+  5 | t
+  6 | t
+  7 | t
+  8 | t
+  9 | t
+ 10 | t
+(10 rows)
+
+-- https://github.com/citusdata/citus/issues/4601
+CREATE TABLE itest13 (a int) using columnar;
+INSERT INTO itest13 VALUES (1), (2), (3);
+ALTER TABLE itest13 ADD COLUMN c int GENERATED BY DEFAULT AS IDENTITY;
+SELECT * FROM itest13 ORDER BY a;
+ a | c
+---------------------------------------------------------------------
+ 1 | 1
+ 2 | 2
+ 3 | 3
+(3 rows)
+
+create table atacc1 (a int) using columnar;
+insert into atacc1 values(1);
+-- should error out. It previously crashed.
+alter table atacc1
+  add column b float8 not null default random(),
+  add primary key(a);
+ERROR:  indexes not supported for columnar tables
+-- Add a generate column with an expression value
+create table test_gen_ex (x int) using columnar;
+INSERT INTO test_gen_ex VALUES (1), (2), (3);
+ALTER TABLE test_gen_ex ADD COLUMN y int generated always as (x+1) stored;
+SELECT * FROM test_gen_ex;
+ x | y
+---------------------------------------------------------------------
+ 1 | 2
+ 2 | 3
+ 3 | 4
+(3 rows)
+
+SET client_min_messages TO WARNING;
+DROP SCHEMA columnar_alter CASCADE;

src/test/regress/sql/am_alter.sql

@@ -1,7 +1,10 @@
 --
--- Testing ALTER TABLE on cstore_fdw tables.
+-- Testing ALTER TABLE on columnar tables.
 --
 
+CREATE SCHEMA columnar_alter;
+SET search_path tO columnar_alter, public;
+
 CREATE TABLE test_alter_table (a int, b int, c int) USING columnar;
 
 WITH sample_data AS (VALUES
@@ -83,3 +86,42 @@ ALTER TABLE test_alter_table ALTER COLUMN k TYPE varchar(20);
 ALTER TABLE test_alter_table ALTER COLUMN k TYPE text;
 
 DROP TABLE test_alter_table;
+
+-- https://github.com/citusdata/citus/issues/4602
+create domain str_domain as text not null;
+create table domain_test (a int, b int) using columnar;
+insert into domain_test values (1, 2);
+insert into domain_test values (1, 2);
+-- the following should error out since the domain is not nullable
+alter table domain_test add column c str_domain;
+-- but this should succeed
+alter table domain_test add column c str_domain DEFAULT 'x';
+SELECT * FROM domain_test;
+
+set default_table_access_method TO 'columnar';
+CREATE TABLE has_volatile AS
+SELECT * FROM generate_series(1,10) id;
+ALTER TABLE has_volatile ADD col4 int DEFAULT (random() * 10000)::int;
+SELECT id, col4 < 10000 FROM has_volatile ORDER BY id;
+
+-- https://github.com/citusdata/citus/issues/4601
+CREATE TABLE itest13 (a int) using columnar;
+INSERT INTO itest13 VALUES (1), (2), (3);
+ALTER TABLE itest13 ADD COLUMN c int GENERATED BY DEFAULT AS IDENTITY;
+SELECT * FROM itest13 ORDER BY a;
+
+create table atacc1 (a int) using columnar;
+insert into atacc1 values(1);
+-- should error out. It previously crashed.
+alter table atacc1
+  add column b float8 not null default random(),
+  add primary key(a);
+
+-- Add a generate column with an expression value
+create table test_gen_ex (x int) using columnar;
+INSERT INTO test_gen_ex VALUES (1), (2), (3);
+ALTER TABLE test_gen_ex ADD COLUMN y int generated always as (x+1) stored;
+SELECT * FROM test_gen_ex;
+
+SET client_min_messages TO WARNING;
+DROP SCHEMA columnar_alter CASCADE;