On Saturday 10 December 2005 20:58, Scott Hudnall wrote: > Since I work as a programmer in laboratory informatics, perhaps I could > lend some insight as to why you often see these sort of abbreviations > sometimes make their way into lab reports. It has nothing to do with an > understanding of SI and everything to do with a compromise programmers have > to make to get their software as database-independent as possible. This > means if you use standard SI and chemistry symbols in your database you run > into a > primary-key violation on the UNITS table since every unit has to have a > unique value. Some database products are case-sensitive, others are not > so some databases can distinguish between mm (millimeter) and mM > (millimolar), while others can not. The best way to ensure that all > databases understand what you mean is to always use all capitol letters > but that means you have to use non-SI symbols in order to have unique > values for every entry. > > Also, to be able store symbols such as Greek letters and math symbols in > text fields, you would need to define the fields as UNICODE....and that is > going to cost you a lot of processor overhead.
This is one reason I'm developing the code. Instead of storing symbols, which can get a bit long such as dK*m^2/W, you store a four-byte integer. The high 16 bits tell you the kind of quantity measured, so you can extract all speeds (if a column contains both speeds and some other quantity) with a single condition. phma
