0c882a2988
f0efa5aec added initReadOnlyStringInfo to allow a StringInfo to be initialized from an existing buffer and also relaxed the requirement that a StringInfo's buffer must be NUL terminated at data[len]. Now that we have that, there's no need for these aggregate deserial functions to use appendBinaryStringInfo() as that rather wastefully palloc'd a new buffer and memcpy'd in the bytea's buffer. Instead, we can just use the bytea's buffer and point the StringInfo directly to that using the new initializer function. In Amdahl's law, this speeds up the serial portion of parallel aggregates and makes sum(numeric), avg(numeric), var_pop(numeric), var_samp(numeric), variance(numeric), stddev_pop(numeric), stddev_samp(numeric), stddev(numeric), array_agg(anyarray), string_agg(text) and string_agg(bytea) scale better in parallel queries. Author: David Rowley Discussion: https://postgr.es/m/CAApHDvr%3De-YOigriSHHm324a40HPqcUhSp6pWWgjz5WwegR%3DcQ%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. 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/.