On CREATE INDEX on AOCO table, check WHERE clause for columns to scan.

Fixes github issue #9022

Reviewed-by: Asim R P <apraveen@pivotal.io>

src/backend/catalog/index.c

@@ -3058,6 +3058,9 @@ IndexBuildAppendOnlyColScan(Relation parentRelation,
 		GetNeededColumnsForScan((Node *)indexInfo->ii_Expressions,
 								proj,
 								parentRelation->rd_att->natts);
+		GetNeededColumnsForScan((Node *)indexInfo->ii_Predicate,
+								proj,
+								parentRelation->rd_att->natts);
 	}
 
 	else

src/test/regress/input/aocs.source

@@ -557,6 +557,32 @@ a.c1
 ;
 
 drop table bms_ao_bug;
+
+
+-- When an index is created on an AOCO table, test that we correctly scan
+-- all the columns that are needed to build the index.
+create table aocs_index_cols (id int4, a text, b text) with (appendonly=true, orientation=column);
+insert into aocs_index_cols values (1, 'foo', 'bar');
+
+-- Create an index on the table. This is the first index on the table, so it
+-- creates the ao block directory, and scans all columns.
+create index on aocs_index_cols (id);
+
+-- Create a partial index. This index needs to scan two columns; one is used
+-- as the index column, and the other in the WHERE clause.
+create index on aocs_index_cols (id) WHERE a like 'f%';
+
+-- Also try an expression index.
+create index on aocs_index_cols (length(b));
+
+-- Check that the row is found using all the indexes.
+set enable_seqscan=off;
+select * from aocs_index_cols where id = 1;
+select * from aocs_index_cols where a like 'f%';
+select * from aocs_index_cols where length(b) = 3;
+reset enable_seqscan;
+
+
 -- Small content as well as bulk dense content headers need to be used
 -- appropriately if compression is found to be not useful.  This test
 -- cover a bug where only small content headers were generated in such

src/test/regress/output/aocs.source

@@ -1143,6 +1143,39 @@ a.c1
 (1 row)
 
 drop table bms_ao_bug;
+-- When an index is created on an AOCO table, test that we correctly scan
+-- all the columns that are needed to build the index.
+create table aocs_index_cols (id int4, a text, b text) with (appendonly=true, orientation=column);
+insert into aocs_index_cols values (1, 'foo', 'bar');
+-- Create an index on the table. This is the first index on the table, so it
+-- creates the ao block directory, and scans all columns.
+create index on aocs_index_cols (id);
+-- Create a partial index. This index needs to scan two columns; one is used
+-- as the index column, and the other in the WHERE clause.
+create index on aocs_index_cols (id) WHERE a like 'f%';
+-- Also try an expression index.
+create index on aocs_index_cols (length(b));
+-- Check that the row is found using all the indexes.
+set enable_seqscan=off;
+select * from aocs_index_cols where id = 1;
+ id |  a  |  b  
+----+-----+-----
+  1 | foo | bar
+(1 row)
+
+select * from aocs_index_cols where a like 'f%';
+ id |  a  |  b  
+----+-----+-----
+  1 | foo | bar
+(1 row)
+
+select * from aocs_index_cols where length(b) = 3;
+ id |  a  |  b  
+----+-----+-----
+  1 | foo | bar
+(1 row)
+
+reset enable_seqscan;
 -- Small content as well as bulk dense content headers need to be used
 -- appropriately if compression is found to be not useful.  This test
 -- cover a bug where only small content headers were generated in such