We've all gotten so used to high-level programming that we often forget about how compact and clean machine code really is. Wait a minute, let's not go there. Machine code may be efficient but who wants to go back to using 1's and 0's in their rapid application development?<\/p>\n
We usually can't use rapid development and efficient code in the same sentence, but there are some areas where the two play nicely together, namely in data storage.<\/p>\n
Consider that you have a database table which stores your customer's preferences. One such column is used to store the days of the week that they prefer to be emailed about daily specials.<\/p>\n
You could create a cross-reference table to store the days of the week, you could create a simple varchar(8) field to store the day numbers or letters. Or, you could revisit those 1's and 0's again.<\/p>\n
What if each day of the week was represented by one bit in an 8-bit TINYINT field? Or, if you have a newer version of MySQL, the bit data type<\/a> would be more appropriate.<\/p>\n 1001001 would mean: Sunday, Wednesday, Saturday<\/p>\n In base 10, this number is 73, and fits nicely inside a single-byte TINYINT field, as suggested above.<\/p>\n Just about every coding language out there provides functions to convert between Base 2 and Base 10. So, consider this approach when you have a large number of records, and storage space is at a premium.<\/p>\n