68689c66ef
Make the inner comparison loops of computeDelta() as tight as possible by pulling considerations of valid and invalid ranges out of the inner loops, and extending a match or non-match detection as far as possible before deciding what to do next. To keep this tractable, give up the possibility of merging fragments across the pd_lower to pd_upper gap. The fraction of pages where that could happen (ie, there are 4 or fewer bytes in the gap, *and* data changes immediately adjacent to it on both sides) is too small to be worth spending cycles on. Also, avoid two BLCKSZ-length memcpy()s by computing the delta before moving data into the target buffer, instead of after. This doesn't save nearly as many cycles as being tenser about computeDelta(), but it still seems worth doing. On my machine, this patch cuts a full 40% off the runtime of contrib/bloom's regression test.
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: http://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 http://www.postgresql.org/download/. For more information look at our web site located at http://www.postgresql.org/.