Cleanup covering infrastructure

- Explicitly forbids opclass, collation and indoptions (like DESC/ASC etc) for
  including columns. Throw an error if user points that.
- Truncated storage arrays for such attributes to store only key atrributes,
  added assertion checks.
- Do not check opfamily and collation for including columns in
  CompareIndexInfo()

Discussion: https://www.postgresql.org/message-id/5ee72852-3c4e-ee35-e2ed-c1d053d45c08@sigaev.ru

src/backend/catalog/index.c

@@ -297,6 +297,7 @@ ConstructTupleDescriptor(Relation heapRelation,
 						 Oid *classObjectId)
 {
 	int			numatts = indexInfo->ii_NumIndexAttrs;
+	int			numkeyatts = indexInfo->ii_NumIndexKeyAttrs;
 	ListCell   *colnames_item = list_head(indexColNames);
 	ListCell   *indexpr_item = list_head(indexInfo->ii_Expressions);
 	IndexAmRoutine *amroutine;
@@ -375,7 +376,8 @@ ConstructTupleDescriptor(Relation heapRelation,
 			to->attidentity = '\0';
 			to->attislocal = true;
 			to->attinhcount = 0;
-			to->attcollation = collationObjectId[i];
+			to->attcollation = (i < numkeyatts) ?
+							collationObjectId[i] : InvalidOid;
 		}
 		else
 		{
@@ -411,7 +413,8 @@ ConstructTupleDescriptor(Relation heapRelation,
 			to->attcacheoff = -1;
 			to->atttypmod = exprTypmod(indexkey);
 			to->attislocal = true;
-			to->attcollation = collationObjectId[i];
+			to->attcollation = (i < numkeyatts) ?
+							collationObjectId[i] : InvalidOid;
 
 			ReleaseSysCache(tuple);
 
@@ -608,9 +611,9 @@ UpdateIndexRelation(Oid indexoid,
 	indkey = buildint2vector(NULL, indexInfo->ii_NumIndexAttrs);
 	for (i = 0; i < indexInfo->ii_NumIndexAttrs; i++)
 		indkey->values[i] = indexInfo->ii_IndexAttrNumbers[i];
-	indcollation = buildoidvector(collationOids, indexInfo->ii_NumIndexAttrs);
+	indcollation = buildoidvector(collationOids, indexInfo->ii_NumIndexKeyAttrs);
 	indclass = buildoidvector(classOids, indexInfo->ii_NumIndexKeyAttrs);
-	indoption = buildint2vector(coloptions, indexInfo->ii_NumIndexAttrs);
+	indoption = buildint2vector(coloptions, indexInfo->ii_NumIndexKeyAttrs);
 
 	/*
 	 * Convert the index expressions (if any) to a text datum
@@ -1081,7 +1084,7 @@ index_create(Relation heapRelation,
 
 		/* Store dependency on collations */
 		/* The default collation is pinned, so don't bother recording it */
-		for (i = 0; i < indexInfo->ii_NumIndexAttrs; i++)
+		for (i = 0; i < indexInfo->ii_NumIndexKeyAttrs; i++)
 		{
 			if (OidIsValid(collationObjectId[i]) &&
 				collationObjectId[i] != DEFAULT_COLLATION_OID)
@@ -1832,6 +1835,11 @@ CompareIndexInfo(IndexInfo *info1, IndexInfo *info2,
 	if (info1->ii_NumIndexAttrs != info2->ii_NumIndexAttrs)
 		return false;
 
+	/* and same number of key attributes */
+	if (info1->ii_NumIndexKeyAttrs != info2->ii_NumIndexKeyAttrs)
+		return false;
+
+
 	/*
 	 * and columns match through the attribute map (actual attribute numbers
 	 * might differ!)  Note that this implies that index columns that are
@@ -1849,6 +1857,10 @@ CompareIndexInfo(IndexInfo *info1, IndexInfo *info2,
 			info1->ii_IndexAttrNumbers[i]))
 			return false;
 
+		/* collation and opfamily is not valid for including columns */
+		if (i >= info1->ii_NumIndexKeyAttrs)
+			continue;
+
 		if (collations1[i] != collations2[i])
 			return false;
 		if (opfamilies1[i] != opfamilies2[i])

src/backend/commands/indexcmds.c

@@ -1359,7 +1359,8 @@ CheckPredicate(Expr *predicate)
 
 /*
  * Compute per-index-column information, including indexed column numbers
- * or index expressions, opclasses, and indoptions.
+ * or index expressions, opclasses, and indoptions. Note, all output vectors
+ * should be allocated for all columns, including "including" ones.
  */
 static void
 ComputeIndexAttrs(IndexInfo *indexInfo,
@@ -1490,6 +1491,36 @@ ComputeIndexAttrs(IndexInfo *indexInfo,
 
 		typeOidP[attn] = atttype;
 
+		/*
+		 * Included columns have no collation, no opclass and no ordering options.
+		 */
+		if (attn >= nkeycols)
+		{
+			if (attribute->collation)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+						 errmsg("including column does not support a collation")));
+			if (attribute->opclass)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+						 errmsg("including column does not support an operator class")));
+			if (attribute->ordering != SORTBY_DEFAULT)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+						 errmsg("including column does not support ASC/DESC options")));
+			if (attribute->nulls_ordering != SORTBY_NULLS_DEFAULT)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+						 errmsg("including column does not support NULLS FIRST/LAST options")));
+
+			classOidP[attn] = InvalidOid;
+			colOptionP[attn] = 0;
+			collationOidP[attn] = InvalidOid;
+			attn++;
+
+			continue;
+		}
+
 		/*
 		 * Apply collation override if any
 		 */
@@ -1521,17 +1552,6 @@ ComputeIndexAttrs(IndexInfo *indexInfo,
 
 		collationOidP[attn] = attcollation;
 
-		/*
-		 * Included columns have no opclass and no ordering options.
-		 */
-		if (attn >= nkeycols)
-		{
-			classOidP[attn] = InvalidOid;
-			colOptionP[attn] = 0;
-			attn++;
-			continue;
-		}
-
 		/*
 		 * Identify the opclass to use.
 		 */

src/backend/optimizer/path/indxpath.c

@@ -2329,8 +2329,8 @@ match_clause_to_indexcol(IndexOptInfo *index,
 {
 	Expr	   *clause = rinfo->clause;
 	Index		index_relid = index->rel->relid;
-	Oid			opfamily = index->opfamily[indexcol];
+	Oid			opfamily;
-	Oid			idxcollation = index->indexcollations[indexcol];
+	Oid			idxcollation;
 	Node	   *leftop,
 			   *rightop;
 	Relids		left_relids;
@@ -2339,6 +2339,11 @@ match_clause_to_indexcol(IndexOptInfo *index,
 	Oid			expr_coll;
 	bool		plain_op;
 
+	Assert(indexcol < index->nkeycolumns);
+
+	opfamily = index->opfamily[indexcol];
+	idxcollation = index->indexcollations[indexcol];
+
 	/* First check for boolean-index cases. */
 	if (IsBooleanOpfamily(opfamily))
 	{
@@ -2678,8 +2683,8 @@ match_clause_to_ordering_op(IndexOptInfo *index,
 							Expr *clause,
 							Oid pk_opfamily)
 {
-	Oid			opfamily = index->opfamily[indexcol];
+	Oid			opfamily;
-	Oid			idxcollation = index->indexcollations[indexcol];
+	Oid			idxcollation;
 	Node	   *leftop,
 			   *rightop;
 	Oid			expr_op;
@@ -2687,6 +2692,10 @@ match_clause_to_ordering_op(IndexOptInfo *index,
 	Oid			sortfamily;
 	bool		commuted;
 
+	Assert(indexcol < index->nkeycolumns);
+
+	opfamily = index->opfamily[indexcol];
+	idxcollation = index->indexcollations[indexcol];
 	/*
 	 * Clause must be a binary opclause.
 	 */
@@ -2921,8 +2930,13 @@ ec_member_matches_indexcol(PlannerInfo *root, RelOptInfo *rel,
 {
 	IndexOptInfo *index = ((ec_member_matches_arg *) arg)->index;
 	int			indexcol = ((ec_member_matches_arg *) arg)->indexcol;
-	Oid			curFamily = index->opfamily[indexcol];
+	Oid			curFamily;
-	Oid			curCollation = index->indexcollations[indexcol];
+	Oid			curCollation;
+
+	Assert(indexcol < index->nkeycolumns);
+
+	curFamily = index->opfamily[indexcol];
+	curCollation = index->indexcollations[indexcol];
 
 	/*
 	 * If it's a btree index, we can reject it if its opfamily isn't
@@ -3548,8 +3562,13 @@ expand_indexqual_conditions(IndexOptInfo *index,
 		RestrictInfo *rinfo = (RestrictInfo *) lfirst(lcc);
 		int			indexcol = lfirst_int(lci);
 		Expr	   *clause = rinfo->clause;
-		Oid			curFamily = index->opfamily[indexcol];
+		Oid			curFamily;
-		Oid			curCollation = index->indexcollations[indexcol];
+		Oid			curCollation;
+
+		Assert(indexcol < index->nkeycolumns);
+
+		curFamily = index->opfamily[indexcol];
+		curCollation = index->indexcollations[indexcol];
 
 		/* First check for boolean cases */
 		if (IsBooleanOpfamily(curFamily))
@@ -3918,14 +3937,15 @@ adjust_rowcompare_for_index(RowCompareExpr *clause,
 		/*
 		 * The Var side can match any column of the index.
 		 */
-		for (i = 0; i < index->ncolumns; i++)
+		for (i = 0; i < index->nkeycolumns; i++)
 		{
 			if (match_index_to_operand(varop, i, index) &&
 				get_op_opfamily_strategy(expr_op,
 										 index->opfamily[i]) == op_strategy &&
 				IndexCollMatchesExprColl(index->indexcollations[i],
 										 lfirst_oid(collids_cell)))
-				break;
+
+			break;
 		}
 		if (i >= index->ncolumns)
 			break;				/* no match found */

src/backend/optimizer/util/plancat.c

@@ -242,7 +242,7 @@ get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent,
 			info->nkeycolumns = nkeycolumns = index->indnkeyatts;
 
 			info->indexkeys = (int *) palloc(sizeof(int) * ncolumns);
-			info->indexcollations = (Oid *) palloc(sizeof(Oid) * ncolumns);
+			info->indexcollations = (Oid *) palloc(sizeof(Oid) * nkeycolumns);
 			info->opfamily = (Oid *) palloc(sizeof(Oid) * nkeycolumns);
 			info->opcintype = (Oid *) palloc(sizeof(Oid) * nkeycolumns);
 			info->canreturn = (bool *) palloc(sizeof(bool) * ncolumns);
@@ -250,7 +250,6 @@ get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent,
 			for (i = 0; i < ncolumns; i++)
 			{
 				info->indexkeys[i] = index->indkey.values[i];
-				info->indexcollations[i] = indexRelation->rd_indcollation[i];
 				info->canreturn[i] = index_can_return(indexRelation, i + 1);
 			}
 
@@ -258,6 +257,7 @@ get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent,
 			{
 				info->opfamily[i] = indexRelation->rd_opfamily[i];
 				info->opcintype[i] = indexRelation->rd_opcintype[i];
+				info->indexcollations[i] = indexRelation->rd_indcollation[i];
 			}
 
 			info->relam = indexRelation->rd_rel->relam;

src/backend/parser/parse_utilcmd.c

@@ -1588,9 +1588,6 @@ generateClonedIndexStmt(RangeVar *heapRel, Oid heapRelid, Relation source_idx,
 		/* Copy the original index column name */
 		iparam->indexcolname = pstrdup(NameStr(attr->attname));
 
-		/* Add the collation name, if non-default */
-		iparam->collation = get_collation(indcollation->values[keyno], keycoltype);
-
 		index->indexIncludingParams = lappend(index->indexIncludingParams, iparam);
 	}
 	/* Copy reloptions if any */

src/backend/utils/adt/ruleutils.c

@@ -1356,15 +1356,15 @@ pg_get_indexdef_worker(Oid indexrelid, int colno,
 		{
 			Oid			indcoll;
 
+			if (keyno >= idxrec->indnkeyatts)
+				continue;
+
 			/* Add collation, if not default for column */
 			indcoll = indcollation->values[keyno];
 			if (OidIsValid(indcoll) && indcoll != keycolcollation)
 				appendStringInfo(&buf, " COLLATE %s",
 								 generate_collation_name((indcoll)));
 
-			if (keyno >= idxrec->indnkeyatts)
-				continue;
-
 			/* Add the operator class name, if not default */
 			get_opclass_name(indclass->values[keyno], keycoltype, &buf);
 

src/backend/utils/adt/selfuncs.c

@@ -7437,6 +7437,8 @@ gincost_pattern(IndexOptInfo *index, int indexcol,
 	int32		searchMode = GIN_SEARCH_MODE_DEFAULT;
 	int32		i;
 
+	Assert(indexcol < index->nkeycolumns);
+
 	/*
 	 * Get the operator's strategy number and declared input data types within
 	 * the index opfamily.  (We don't need the latter, but we use

src/backend/utils/cache/relcache.c

@@ -1637,10 +1637,10 @@ RelationInitIndexAccessInfo(Relation relation)
 	}
 
 	relation->rd_indcollation = (Oid *)
-		MemoryContextAllocZero(indexcxt, indnatts * sizeof(Oid));
+		MemoryContextAllocZero(indexcxt, indnkeyatts * sizeof(Oid));
 
 	relation->rd_indoption = (int16 *)
-		MemoryContextAllocZero(indexcxt, indnatts * sizeof(int16));
+		MemoryContextAllocZero(indexcxt, indnkeyatts * sizeof(int16));
 
 	/*
 	 * indcollation cannot be referenced directly through the C struct,
@@ -1653,7 +1653,7 @@ RelationInitIndexAccessInfo(Relation relation)
 							   &isnull);
 	Assert(!isnull);
 	indcoll = (oidvector *) DatumGetPointer(indcollDatum);
-	memcpy(relation->rd_indcollation, indcoll->values, indnatts * sizeof(Oid));
+	memcpy(relation->rd_indcollation, indcoll->values, indnkeyatts * sizeof(Oid));
 
 	/*
 	 * indclass cannot be referenced directly through the C struct, because it
@@ -1685,7 +1685,7 @@ RelationInitIndexAccessInfo(Relation relation)
 								 &isnull);
 	Assert(!isnull);
 	indoption = (int2vector *) DatumGetPointer(indoptionDatum);
-	memcpy(relation->rd_indoption, indoption->values, indnatts * sizeof(int16));
+	memcpy(relation->rd_indoption, indoption->values, indnkeyatts * sizeof(int16));
 
 	/*
 	 * expressions, predicate, exclusion caches will be filled later