Set a snapshot before running analyze on a single table, to avoid a

crash when analyzing tables with expressional indexes.

Per report from Frank van Vugt.

src/backend/postmaster/autovacuum.c

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.6 2005/11/22 18:17:17 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.7 2005/11/28 13:35:09 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -898,6 +898,14 @@ autovacuum_do_vac_analyze(List *relids, bool dovacuum, bool doanalyze,
 	vacstmt->relation = NULL;	/* all tables, or not used if relids != NIL */
 	vacstmt->va_cols = NIL;
 
+	/*
+	 * Functions in indexes may want a snapshot set.  Note we only need
+	 * to do this in limited cases, because it'll be done in vacuum()
+	 * otherwise.
+	 */
+	if (doanalyze && !dovacuum && relids != NIL)
+		ActiveSnapshot = CopySnapshot(GetTransactionSnapshot());
+
 	vacuum(vacstmt, relids);
 
 	pfree(vacstmt);