4c8ad67a98
_bt_first need only store one ScanKeyData struct on the stack for the purposes of building an IS NOT NULL key based on an implied NOT NULL constraint. We don't need INDEX_MAX_KEYS-many ScanKeyData structs. This saves us a little over 2KB in stack space. It's possible that this has some performance benefit. It also seems simpler and more direct. It isn't possible for more than a single index attribute to need its own implied IS NOT NULL key: the first such attribute/IS NOT NULL key always makes _bt_first stop adding additional boundary keys to startKeys[]. Using INDEX_MAX_KEYS-many ScanKeyData entries was (at best) misleading. Author: Peter Geoghegan <pg@bowt.ie> Reviewed-By: Mircea Cadariu <cadariu.mircea@gmail.com> Discussion: https://postgr.es/m/CAH2-Wzm=1kJMSZhhTLoM5BPbwQNWxUj-ynOEh=89ptDZAVgauw@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/.