d3d3ec0d89
It is possible for a NestLoop plan node to pass an OUTER Var into an "inner indexscan" that is an Append construct (derived from an inheritance tree or UNION ALL subquery). The OUTER tuple is then passed down at runtime to the leaf indexscan node(s) where it will actually be used. EXPLAIN has to likewise pass the information about the nestloop's outer subplan down through the Append node, else it will fail to print the outer-reference Vars (with complaints like "bogus varno: 65001"). However, there was a case missed in all this: we could also have gating Result nodes that were inserted into the appendrel plan tree to deal with pseudoconstant qual conditions. So EXPLAIN has to pass down the outer plan node to a Result's subplan, too. Per example from Jon Nelson. The problem is gone in 9.1 because we replaced the nestloop outer-tuple kluge with a Param-based data transfer mechanism. Also, so far as I can tell, the case can't happen before 8.4 because of restrictions on what sorts of appendrel members could be pulled up into the parent query. So this patch is only needed for 8.4 and 9.0.
PostgreSQL Database Management System ===================================== This directory contains the source code distribution of the PostgreSQL database management system. PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings. PostgreSQL has many language interfaces, many of which are listed here: http://www.postgresql.org/download See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Changes between all PostgreSQL releases are recorded in the file HISTORY. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at http://www.postgresql.org/download/. For more information look at our web site located at http://www.postgresql.org/.