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In each of the create_*_bound() functions for LIST, RANGE and HASH partitioning, there were a large number of palloc calls which could be reduced down to a much smaller number. In each of these functions, an array was built so that we could qsort it before making the PartitionBoundInfo. For LIST and HASH partitioning, an array of pointers was allocated then each element was allocated within that array. Since the number of items of each dimension is known beforehand, we can just allocate a single chunk of memory for this. Similarly, with all partition strategies, we're able to reduce the number of allocations to build the ->datums field. This is an array of Datum pointers, but there's no need for the Datums that each element points to to be singly allocated. One big chunk will do. For RANGE partitioning, the PartitionBoundInfo->kind field can get the same treatment. We can apply the same optimizations to partition_bounds_copy(). Doing this might have a small effect on cache performance when searching for the correct partition during partition pruning or DML on a partitioned table. However, that's likely to be small and this is mostly about reducing palloc overhead. Author: Nitin Jadhav, Justin Pryzby, David Rowley Reviewed-by: Justin Pryzby, Zhihong Yu Discussion: https://postgr.es/m/flat/CAMm1aWYFTqEio3bURzZh47jveiHRwgQTiSDvBORczNEz2duZ1Q@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. 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/.