468abb8f7a
In 499be013de support for pruning unneeded Append subnodes was added. The logic in that commit was not correctly checking if the next subplan was in fact a valid subplan. This could cause parallel workers processes to be given a subplan to work on which didn't require any work. Per code review following an otherwise unexplained regression failure in buildfarm member Pademelon. (We haven't been able to reproduce the failure, so this is a bit of a blind fix in terms of whether it'll actually fix it; but it is a clear bug nonetheless). In passing, also add a comment to explain what first_partial_plan means. Author: David Rowley Discussion: https://postgr.es/m/CAKJS1f_E5r05hHUVG3UmCQJ49DGKKHtN=SHybD44LdzBn+CJng@mail.gmail.com
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: https://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. 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 https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.