Replace functional-index facility with expressional indexes. Any column

of an index can now be a computed expression instead of a simple variable.
Restrictions on expressions are the same as for predicates (only immutable
functions, no sub-selects).  This fixes problems recently introduced with
inlining SQL functions, because the inlining transformation is applied to
both expression trees so the planner can still match them up.  Along the
way, improve efficiency of handling index predicates (both predicates and
index expressions are now cached by the relcache) and fix 7.3 oversight
that didn't record dependencies of predicate expressions.

1 files changed, 23 insertions, 32 deletions

diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
index 09ef0ac598e..87062782456 100644
--- a/src/backend/commands/cluster.c
+++ b/src/backend/commands/cluster.c
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/cluster.c,v 1.109 2003/05/14 03:26:01 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/cluster.c,v 1.110 2003/05/28 16:03:56 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -214,7 +214,7 @@ cluster(ClusterStmt *stmt)
 
 			/* Start a new transaction for each relation. */
 			StartTransactionCommand();
-			SetQuerySnapshot();	/* might be needed for functional index */
+			SetQuerySnapshot();	/* might be needed for functions in indexes */
 			cluster_rel(rvtc, true);
 			CommitTransactionCommand();
 		}
@@ -320,7 +320,7 @@ cluster_rel(RelToCluster *rvtc, bool recheck)
 	 * seqscan pass over the table to copy the missing rows, but that seems
 	 * expensive and tedious.
 	 */
-	if (VARSIZE(&OldIndex->rd_index->indpred) > VARHDRSZ) /* partial? */
+	if (!heap_attisnull(OldIndex->rd_indextuple, Anum_pg_index_indpred))
 		elog(ERROR, "CLUSTER: cannot cluster on partial index");
 	if (!OldIndex->rd_am->amindexnulls)
 	{
@@ -332,14 +332,24 @@ cluster_rel(RelToCluster *rvtc, bool recheck)
 		 * at the first column; multicolumn-capable AMs are *required* to
 		 * index nulls in columns after the first.
 		 */
-		if (OidIsValid(OldIndex->rd_index->indproc))
-			elog(ERROR, "CLUSTER: cannot cluster on functional index when index access method does not handle nulls");
 		colno = OldIndex->rd_index->indkey[0];
-		if (colno > 0)			/* system columns are non-null */
+		if (colno > 0)
+		{
+			/* ordinary user attribute */
 			if (!OldHeap->rd_att->attrs[colno - 1]->attnotnull)
 				elog(ERROR, "CLUSTER: cannot cluster when index access method does not handle nulls"
 					 "\n\tYou may be able to work around this by marking column \"%s\" NOT NULL",
 					 NameStr(OldHeap->rd_att->attrs[colno - 1]->attname));
+		}
+		else if (colno < 0)
+		{
+			/* system column --- okay, always non-null */
+		}
+		else
+		{
+			/* index expression, lose... */
+			elog(ERROR, "CLUSTER: cannot cluster on expressional index when index access method does not handle nulls");
+		}
 	}
 
 	/*
@@ -557,43 +567,24 @@ get_indexattr_list(Relation OldHeap, Oid OldIndex)
 	foreach(indlist, RelationGetIndexList(OldHeap))
 	{
 		Oid			indexOID = lfirsto(indlist);
-		HeapTuple	indexTuple;
-		HeapTuple	classTuple;
-		Form_pg_index indexForm;
-		Form_pg_class classForm;
+		Relation	oldIndex;
 		IndexAttrs *attrs;
 
-		indexTuple = SearchSysCache(INDEXRELID,
-									ObjectIdGetDatum(indexOID),
-									0, 0, 0);
-		if (!HeapTupleIsValid(indexTuple))
-			elog(ERROR, "Cache lookup failed for index %u", indexOID);
-		indexForm = (Form_pg_index) GETSTRUCT(indexTuple);
-		Assert(indexForm->indexrelid == indexOID);
+		oldIndex = index_open(indexOID);
 
 		attrs = (IndexAttrs *) palloc(sizeof(IndexAttrs));
 		attrs->indexOID = indexOID;
-		attrs->indexInfo = BuildIndexInfo(indexForm);
+		attrs->indexName = pstrdup(NameStr(oldIndex->rd_rel->relname));
+		attrs->accessMethodOID = oldIndex->rd_rel->relam;
+		attrs->indexInfo = BuildIndexInfo(oldIndex);
 		attrs->classOID = (Oid *)
 			palloc(sizeof(Oid) * attrs->indexInfo->ii_NumIndexAttrs);
-		memcpy(attrs->classOID, indexForm->indclass,
+		memcpy(attrs->classOID, oldIndex->rd_index->indclass,
 			   sizeof(Oid) * attrs->indexInfo->ii_NumIndexAttrs);
 		/* We adjust the isclustered attribute to correct new state */
 		attrs->isclustered = (indexOID == OldIndex);
 
-		/* Name and access method of each index come from pg_class */
-		classTuple = SearchSysCache(RELOID,
-									ObjectIdGetDatum(indexOID),
-									0, 0, 0);
-		if (!HeapTupleIsValid(classTuple))
-			elog(ERROR, "Cache lookup failed for index %u", indexOID);
-		classForm = (Form_pg_class) GETSTRUCT(classTuple);
-
-		attrs->indexName = pstrdup(NameStr(classForm->relname));
-		attrs->accessMethodOID = classForm->relam;
-
-		ReleaseSysCache(classTuple);
-		ReleaseSysCache(indexTuple);
+		index_close(oldIndex);
 
 		/*
 		 * Cons the gathered data into the list.  We do not care about