Pass 'page', 'blockno' and 'maxoff' to heap_prune_chain() as arguments, so that it doesn't need to fetch them from the buffer. This saves a few cycles per chain. Remove the "if (off_loc != NULL)" checks, and require the caller to pass a non-NULL 'off_loc'. Pass a pointer to a dummy local variable when it's not needed. Those checks are cheap, but it's still better to avoid them in the per-chain loops when we can do so easily. The CPU time saving from these changes are hardly measurable, but fewer instructions is good anyway, so why not. I spotted the potential for these while reviewing Melanie Plageman's patch set to combine prune and freeze records. Discussion: https://www.postgresql.org/message-id/CAAKRu_abm2tHhrc0QSQa%3D%3DsHe%3DVA1%3Doz1dJMQYUOKuHmu%2B9Xrg%40mail.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/.