The disadvantage is that languages such as English have large numbers of irregular words that are pronounced in a very different way from how they're written (such as "colonel," which we say as kernel and not "coll-o-nell"; and "yacht," which is pronounced "yot" and not "yach-t")...
This is useful if you want to be able to have multiple execution plans stored in the plan table at once—giving each execution plan a distinct name enables you to determine which rows in the plan table belong to which execution plan. The EXPLAIN PLAN statement runs quickly because all Oracle...