If that is all you need1, then just add the simple field.
But, you'll have to be careful about how you index it. Unless the values are seriously skewed2, you'll end-up with an index with a horrible selectivity and clustering factor3, and you'll actually be better off doing full table scans4.
如果您按标志过滤结合起来与其他字段一起创建一个综合索引，这样就有更好的机会进行适当的选择。
1 I.e. you don't need additional data that somehow "describes" or "augments" each of the two possible Boolean values.
2 One value is in deep minority (the number of rows containing false is much smaller than the number of rows containing true, or vice verse), and you happen to filter on just that value.
3 The link is for Oracle, but the general principle applies to all DBMSes.
4 Which a decent DBMS will do for you automatically, even in the presence of the index. A hypothetical "stupid" DBMS would just blindly use the index and perform even worse than the full table scan.
