ALTER TABLE DROP COLUMN works. Patch by Christopher Kings-Lynne,

code review by Tom Lane.  Remaining issues: functions that take or
return tuple types are likely to break if one drops (or adds!)
a column in the table defining the type.  Need to think about what
to do here.

Along the way: some code review for recent COPY changes; mark system
columns attnotnull = true where appropriate, per discussion a month ago.

2 files changed, 16 insertions, 2 deletions

diff --git a/src/backend/rewrite/rewriteDefine.c b/src/backend/rewrite/rewriteDefine.c
index 59d0744dcee..577ce2bd52d 100644
--- a/src/backend/rewrite/rewriteDefine.c
+++ b/src/backend/rewrite/rewriteDefine.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteDefine.c,v 1.75 2002/07/16 05:53:34 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteDefine.c,v 1.76 2002/08/02 18:15:07 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -257,6 +257,16 @@ DefineQueryRewrite(RuleStmt *stmt)
 			attr = event_relation->rd_att->attrs[i - 1];
 			attname = NameStr(attr->attname);
 
+			/*
+			 * Disallow dropped columns in the relation.  This won't happen
+			 * in the cases we actually care about (namely creating a view
+			 * via CREATE TABLE then CREATE RULE).  Trying to cope with it
+			 * is much more trouble than it's worth, because we'd have to
+			 * modify the rule to insert dummy NULLs at the right positions.
+			 */
+			if (attr->attisdropped)
+				elog(ERROR, "cannot convert relation containing dropped columns to view");
+
 			if (strcmp(resdom->resname, attname) != 0)
 				elog(ERROR, "select rule's target entry %d has different column name from %s", i, attname);
 
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
index 0ae1e223baa..95ab639d0a7 100644
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.104 2002/07/18 04:43:50 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.105 2002/08/02 18:15:07 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -264,6 +264,10 @@ rewriteTargetList(Query *parsetree, Relation target_relation)
 		Form_pg_attribute att_tup = target_relation->rd_att->attrs[attrno-1];
 		TargetEntry *new_tle = NULL;
 
+		/* We can ignore deleted attributes */
+		if (att_tup->attisdropped)
+			continue;
+
 		/*
 		 * Look for targetlist entries matching this attr.  We match by
 		 * resno, but the resname should match too.