mirror of
https://github.com/postgres/postgres.git
synced 2025-05-09 18:21:05 +03:00
489e431ba5
Remove a Berkeley-era comment above _bt_insertonpg() that admonishes the reader to grok Lehman and Yao's paper before making any changes. This made a certain amount of sense back when _bt_insertonpg() was responsible for most of the things that are now spread across _bt_insertonpg(), _bt_findinsertloc(), _bt_insert_parent(), and _bt_split(), but it doesn't work like that anymore. I believe that this comment alludes to the need to "couple" or "crab" buffer locks as we ascend the tree as page splits cascade upwards. The nbtree README already explains this in detail, which seems sufficient. Besides, the changes to page splits made by commit 40dae7ec537 altered the exact details of how buffer locks are retained during splits; Lehman and Yao's original algorithm seems to release the lock on the left child page/buffer slightly earlier than _bt_insertonpg()/_bt_insert_parent() can.
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. PostgreSQL has many language interfaces, many of which are listed here: https://www.postgresql.org/download See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.