5dd7fc1519
Adds accounting of memory allocated in a memory context. Compared to various ad hoc solutions, the main advantage is that the accounting is transparent and does not require direct control over allocations (this matters for use cases where the allocations happen in user code, like for example aggregate states allocated in a transition functions). To reduce overhead, the accounting happens at the block level (not for individual chunks) and only the context immediately owning the block is updated. When inquiring about amount of memory allocated in a context, we have to recursively walk all children contexts. This "lazy" accounting works well for cases with relatively small number of contexts in the relevant subtree and/or with infrequent inquiries. Author: Jeff Davis Reivewed-by: Tomas Vondra, Melanie Plageman, Soumyadeep Chakraborty Discussion: https://www.postgresql.org/message-id/flat/027a129b8525601c6a680d27ce3a7172dab61aab.camel@j-davis.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. 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/.