26255a3207
Typically, we have only one PlannerInfo for any given subquery, but when we are considering a MinMaxAggPath or a hashed subplan, we end up creating a second PlannerInfo for the same portion of the query, with a clone of the original range table. In fact, in the MinMaxAggPath case, we might end up creating several clones, one per aggregate. At present, there's no easy way for a plugin, such as pg_plan_advice, to understand the relationships between the original range table and the copies of it that are created in these cases. To fix, add an alternative_plan_name field to PlannerInfo. For a hashed subplan, this is the plan name for the non-hashed alternative; for minmax aggregates, this is the plan_name from the parent PlannerInfo; otherwise, it's the same as plan_name. Discussion: http://postgr.es/m/CA+TgmoYuWmN-00Ec5pY7zAcpSFQUQLbgAdVWGR9kOR-HM-fHrA@mail.gmail.com Reviewed-by: Lukas Fittl <lukas@fittl.com> |
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| aclocal.m4 | ||
| configure | ||
| configure.ac | ||
| COPYRIGHT | ||
| GNUmakefile.in | ||
| HISTORY | ||
| Makefile | ||
| meson.build | ||
| meson_options.txt | ||
| README.md | ||
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/.