mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-08-21 06:53:23 +02:00
ef655663c5
After further thought about implicit coercions appearing in a joinaliasvars list, I realized that they represent an additional reason why we might need to reference the join output column directly instead of referencing an underlying column. Consider SELECT x FROM t1 LEFT JOIN t2 USING (x) where t1.x is of type date while t2.x is of type timestamptz. The merged output variable is of type timestamptz, but it won't go to null when t2 does, therefore neither t1.x nor t2.x is a valid substitute reference. The code in get_variable() actually gets this case right, since it knows it shouldn't look through a coercion, but we failed to ensure that the unqualified output column name would be globally unique. To fix, modify the code that trawls for a dangerous situation so that it actually scans through an unnamed join's joinaliasvars list to see if there are any non-simple-Var entries. |
||
|---|---|---|
| config | ||
| contrib | ||
| doc | ||
| src | ||
| .gitignore | ||
| aclocal.m4 | ||
| configure | ||
| configure.in | ||
| COPYRIGHT | ||
| GNUmakefile.in | ||
| Makefile | ||
| README | ||
| README.git | ||
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/.