f2bae51dfd
Result nodes now include an RTI set, which is only non-NULL when they have no subplan, and is taken from the relid set of the RelOptInfo that the Result is generating. ExplainPreScanNode now takes notice of these RTIs, which means that a few things get schema-qualified in the regression tests that previously did not. This makes the output more consistent between cases where some part of the plan tree is replaced by a Result node and those where this does not happen. Likewise, pg_overexplain's EXPLAIN (RANGE_TABLE) now displays the RTIs stored in a Result node just as it already does for other RTI-bearing node types. Result nodes also now include a result_reason, which tells us something about why the Result node was inserted. Using that information, EXPLAIN now emits, where relevant, a "Replaces" line describing the origin of a Result node. The purpose of these changes is to allow code that inspects a Plan tree to understand the origin of Result nodes that appear therein. Discussion: http://postgr.es/m/CA+TgmoYeUZePZWLsSO+1FAN7UPePT_RMEZBKkqYBJVCF1s60=w@mail.gmail.com Reviewed-by: Alexandra Wang <alexandra.wang.oss@gmail.com> Reviewed-by: Richard Guo <guofenglinux@gmail.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Junwang Zhao <zhjwpku@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/.