c22dea8900
has a small maxBlockSize: the maximum request size that we will treat as a "chunk" needs to be limited to fit in maxBlockSize. Otherwise we will round up the request size to the next power of 2, wasting space, which is a bit pointless if we aren't going to make the blocks big enough to fit additional stuff in them. The example motivating this is local buffer management, which makes repeated allocations of 8K (one BLCKSZ buffer) in TopMemoryContext, which has maxBlockSize = 8K because for the most part allocations there are small. This leads to each local buffer actually eating 16K of space, which adds up when there are thousands of them. I intend to change localbuf.c to aggregate its requests, which will prevent this particular misbehavior, but it seems likely that similar scenarios could arise elsewhere, so fixing the core problem seems wise as well.
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 including some of the more common listed below: C++ - http://thaiopensource.org/development/libpqxx/ JDBC - http://jdbc.postgresql.org ODBC - http://odbc.postgresql.org Perl - http://search.cpan.org/~dbdpg/ PHP - http://www.php.net Python - http://www.initd.org/ Ruby - http://ruby.scripting.ca/postgres/ Other language binding are available from a variety of contributing parties. PostgreSQL also has a great number of procedural languages available, a short but not complete list is below: PL/pgSQL - included in PostgreSQL source distribution PL/Perl - included in PostgreSQL source distribution PL/PHP - http://projects.commandprompt.com/projects/public/plphp PL/Python - included in PostgreSQL source distribution PL/Java - http://gborg.postgresql.org/project/pljava/projdisplay.php PL/Tcl - included in PostgreSQL source distribution 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. Changes between all PostgreSQL releases are recorded in the file HISTORY. 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 http://www.postgresql.org/download/. For more information look at our web site located at http://www.postgresql.org/.