Fix interference between cavering indexes and partitioned tables

The bug is caused due to the original IndexStmt that DefineIndex receives
being overwritten when processing the INCLUDE columns. Use separate list of
index params to propagate to child tables. Add tests covering this case.

Amit Langote and Alexander Korotkov.

src/backend/commands/indexcmds.c

@@ -342,6 +342,7 @@ DefineIndex(Oid relationId,
 	Oid			tablespaceId;
 	Oid			createdConstraintId = InvalidOid;
 	List	   *indexColNames;
+	List	   *allIndexParams;
 	Relation	rel;
 	Relation	indexRelation;
 	HeapTuple	tuple;
@@ -378,16 +379,16 @@ DefineIndex(Oid relationId,
 	numberOfKeyAttributes = list_length(stmt->indexParams);
 
 	/*
-	 * We append any INCLUDE columns onto the indexParams list so that we have
-	 * one list with all columns.  Later we can determine which of these are
-	 * key columns, and which are just part of the INCLUDE list by checking
-	 * the list position.  A list item in a position less than
-	 * ii_NumIndexKeyAttrs is part of the key columns, and anything equal to
-	 * and over is part of the INCLUDE columns.
+	 * Calculate the new list of index columns including both key columns and
+	 * INCLUDE columns.  Later we can determine which of these are key columns,
+	 * and which are just part of the INCLUDE list by checking the list
+	 * position.  A list item in a position less than ii_NumIndexKeyAttrs is
+	 * part of the key columns, and anything equal to and over is part of the
+	 * INCLUDE columns.
 	 */
-	stmt->indexParams = list_concat(stmt->indexParams,
-									stmt->indexIncludingParams);
-	numberOfAttributes = list_length(stmt->indexParams);
+	allIndexParams = list_concat(list_copy(stmt->indexParams),
+								 list_copy(stmt->indexIncludingParams));
+	numberOfAttributes = list_length(allIndexParams);
 
 	if (numberOfAttributes <= 0)
 		ereport(ERROR,
@@ -544,7 +545,7 @@ DefineIndex(Oid relationId,
 	/*
 	 * Choose the index column names.
 	 */
-	indexColNames = ChooseIndexColumnNames(stmt->indexParams);
+	indexColNames = ChooseIndexColumnNames(allIndexParams);
 
 	/*
 	 * Select name for index if caller didn't specify
@@ -658,7 +659,7 @@ DefineIndex(Oid relationId,
 	coloptions = (int16 *) palloc(numberOfAttributes * sizeof(int16));
 	ComputeIndexAttrs(indexInfo,
 					  typeObjectId, collationObjectId, classObjectId,
-					  coloptions, stmt->indexParams,
+					  coloptions, allIndexParams,
 					  stmt->excludeOpNames, relationId,
 					  accessMethodName, accessMethodId,
 					  amcanorder, stmt->isconstraint);
@@ -886,8 +887,8 @@ DefineIndex(Oid relationId,
 			memcpy(part_oids, partdesc->oids, sizeof(Oid) * nparts);
 
 			parentDesc = CreateTupleDescCopy(RelationGetDescr(rel));
-			opfamOids = palloc(sizeof(Oid) * numberOfAttributes);
-			for (i = 0; i < numberOfAttributes; i++)
+			opfamOids = palloc(sizeof(Oid) * numberOfKeyAttributes);
+			for (i = 0; i < numberOfKeyAttributes; i++)
 				opfamOids[i] = get_opclass_family(classObjectId[i]);
 
 			heap_close(rel, NoLock);

src/test/regress/expected/indexing.out

@@ -1313,3 +1313,27 @@ alter index idxpart2_a_idx attach partition idxpart22_a_idx;
 create index on idxpart (a);
 create table idxpart_another (a int, b int, primary key (a, b)) partition by range (a);
 create table idxpart_another_1 partition of idxpart_another for values from (0) to (100);
+-- Test that covering partitioned indexes work in various cases
+create table covidxpart (a int, b int) partition by list (a);
+create unique index on covidxpart (a) include (b);
+create table covidxpart1 partition of covidxpart for values in (1);
+create table covidxpart2 partition of covidxpart for values in (2);
+insert into covidxpart values (1, 1);
+insert into covidxpart values (1, 1);
+ERROR:  duplicate key value violates unique constraint "covidxpart1_a_b_idx"
+DETAIL:  Key (a)=(1) already exists.
+create table covidxpart3 (b int, c int, a int);
+alter table covidxpart3 drop c;
+alter table covidxpart attach partition covidxpart3 for values in (3);
+insert into covidxpart values (3, 1);
+insert into covidxpart values (3, 1);
+ERROR:  duplicate key value violates unique constraint "covidxpart3_a_b_idx"
+DETAIL:  Key (a)=(3) already exists.
+create table covidxpart4 (b int, a int);
+create unique index on covidxpart4 (a) include (b);
+create unique index on covidxpart4 (a);
+alter table covidxpart attach partition covidxpart4 for values in (4);
+insert into covidxpart values (4, 1);
+insert into covidxpart values (4, 1);
+ERROR:  duplicate key value violates unique constraint "covidxpart4_a_b_idx"
+DETAIL:  Key (a)=(4) already exists.

src/test/regress/sql/indexing.sql

@@ -701,3 +701,22 @@ alter index idxpart2_a_idx attach partition idxpart22_a_idx;
 create index on idxpart (a);
 create table idxpart_another (a int, b int, primary key (a, b)) partition by range (a);
 create table idxpart_another_1 partition of idxpart_another for values from (0) to (100);
+
+-- Test that covering partitioned indexes work in various cases
+create table covidxpart (a int, b int) partition by list (a);
+create unique index on covidxpart (a) include (b);
+create table covidxpart1 partition of covidxpart for values in (1);
+create table covidxpart2 partition of covidxpart for values in (2);
+insert into covidxpart values (1, 1);
+insert into covidxpart values (1, 1);
+create table covidxpart3 (b int, c int, a int);
+alter table covidxpart3 drop c;
+alter table covidxpart attach partition covidxpart3 for values in (3);
+insert into covidxpart values (3, 1);
+insert into covidxpart values (3, 1);
+create table covidxpart4 (b int, a int);
+create unique index on covidxpart4 (a) include (b);
+create unique index on covidxpart4 (a);
+alter table covidxpart attach partition covidxpart4 for values in (4);
+insert into covidxpart values (4, 1);
+insert into covidxpart values (4, 1);