Let us consider the following (hypothetical/real) case: we have a fruit basket with an assortment of fruits in it. Over a period of time, let us suppose we accumulate so much fruit [will they not stink? may be – but that’s a problem beyond the scope of PERL & MySQL] that one basket can no longer hold all the fruits. One possible [and meaningful] way to solve this problem is to introduce another basket and segregate fruits into either one of the two baskets. To make it bit more elegant, we should probably make sure that a given kind of fruit is stored in only one of the baskets. Then, when someone asks us for a fruit – say an Apple – we know which basket contains apples and we can readily pick them out; when someone else asks for an Orange, we can repeat the process; and so on.