7a80e381d1
There's no need for set_simple_column_names() to compute unique column names for join RTEs, because a finished plan tree will not contain any join alias Vars that we could need names for. Its other, internal callers will not pass it any join RTEs anyway, so the upshot is we can just skip join RTEs here. Aside from getting rid of a klugy against-its-documentation use of set_relation_column_names, this can speed up EXPLAIN substantially when considering many-join queries, because the upper join RTEs tend to have a lot of columns. Sami Imseih, with cosmetic changes by me Discussion: https://postgr.es/m/CAA5RZ0th3q-0p1pri58z9grG8r8azmEBa8o1rtkwhLmJg_cH+g@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.
Copyright and license information can be found in the file COPYRIGHT.
General documentation about this version of PostgreSQL can be found at https://www.postgresql.org/docs/devel/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/devel/installation.html.
The latest version of this software, and related software, may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.