A lot of the examples in this section are quite ancient and no longer match the system's current behavior. I ran through them and updated the sample output to match what I get today. Notably, it seems that the tenk1 table got a few pages smaller back around v12, so that a lot of the cost estimates for queries on that table are a little different now. (This also caused some examples to surprisingly not match others, depending on when they were made.) One mergejoin-based example no longer produces the same plan at all, so I had to work around that, including switching to a different example of using an enable_xxx setting. I also changed a couple of examples that were relying on nonexistent tables or indexes. IMO the premise of this section is that the examples should be more-or-less reproducible against the regression database, so that these examples were unhelpful as given. It's not that hard to find a corresponding example with the tables we do have. Some of the EXPLAIN ANALYZE examples were out of date in that we show more numbers than we did at the time. Possibly chapter 68 could use similar review, but I'm out of energy for today.
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/.