Restructure parsetree representation of DECLARE CURSOR: now it's a

utility statement (DeclareCursorStmt) with a SELECT query dangling from
it, rather than a SELECT query with a few unusual fields in it.  Add
code to determine whether a planned query can safely be run backwards.
If DECLARE CURSOR specifies SCROLL, ensure that the plan can be run
backwards by adding a Materialize plan node if it can't.  Without SCROLL,
you get an error if you try to fetch backwards from a cursor that can't
handle it.  (There is still some discussion about what the exact
behavior should be, but this is necessary infrastructure in any case.)
Along the way, make EXPLAIN DECLARE CURSOR work.

1 files changed, 20 insertions, 5 deletions

diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index 410d092c916..fb1ea0c94d0 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.149 2003/02/16 02:30:37 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.150 2003/03/10 03:53:49 tgl Exp $
  *
  * NOTES
  *	  Path and Plan nodes do not have any readfuncs support, because we
@@ -198,8 +198,6 @@ _readQuery(void)
 	READ_NODE_FIELD(utilityStmt);
 	READ_INT_FIELD(resultRelation);
 	READ_NODE_FIELD(into);
-	READ_BOOL_FIELD(isPortal);
-	READ_BOOL_FIELD(isBinary);
 	READ_BOOL_FIELD(hasAggs);
 	READ_BOOL_FIELD(hasSubLinks);
 	READ_NODE_FIELD(rtable);
@@ -234,6 +232,21 @@ _readNotifyStmt(void)
 }
 
 /*
+ * _readDeclareCursorStmt
+ */
+static DeclareCursorStmt *
+_readDeclareCursorStmt(void)
+{
+	READ_LOCALS(DeclareCursorStmt);
+
+	READ_STRING_FIELD(portalname);
+	READ_INT_FIELD(options);
+	READ_NODE_FIELD(query);
+
+	READ_DONE();
+}
+
+/*
  * _readSortClause
  */
 static SortClause *
@@ -894,8 +907,6 @@ parseNodeString(void)
 
 	if (MATCH("QUERY", 5))
 		return_value = _readQuery();
-	else if (MATCH("NOTIFY", 6))
-		return_value = _readNotifyStmt();
 	else if (MATCH("SORTCLAUSE", 10))
 		return_value = _readSortClause();
 	else if (MATCH("GROUPCLAUSE", 11))
@@ -966,6 +977,10 @@ parseNodeString(void)
 		return_value = _readExprFieldSelect();
 	else if (MATCH("RTE", 3))
 		return_value = _readRangeTblEntry();
+	else if (MATCH("NOTIFY", 6))
+		return_value = _readNotifyStmt();
+	else if (MATCH("DECLARECURSOR", 13))
+		return_value = _readDeclareCursorStmt();
 	else
 	{
 		elog(ERROR, "badly formatted node string \"%.32s\"...", token);