1. If a record is inserted into or removed from a data fi le, you must make the corresponding change to the index fi le. If a data fi le has more than one index fi le, you must update each index fi...

1. If a record is inserted into or removed from a data fi le, you must make the corresponding change to the index fi le. If a data fi le has more than one index fi le, you must update each index fi le. Thus, multiple indexing has an overhead.

2. You can organize an index fi le by using either hashing or a B-tree. These schemes allow you to perform the basic dictionary operations by using only a few block accesses.