I just read an article on LWN.net about the usage of self-modifying code for selecting the optimum code for a given operation at run time. This is probably not a highly portable technique, but Linux has definitions for i386 and the amd64 archs, so that would cover the most common scenarios.
This could be useful to provide different TAS implementations depending on the actual system the code is running on. The article is here: http://lwn.net/SubscriberLink/164121/d88fddbb5606a938/ The i386 code is here: http://lxr.linux.no/source/include/asm-i386/system.h#L288 -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc. ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
