A database is a collection of related pieces of information that is organized for easy retrieval....

 

  

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A database is a collection of related pieces of information that is organized for easy retrieval. The set of accounts records shown below (named "accounts.dat"), for instance, form an accounts database. Record# 0 1 2 3 4 5 6 7 8 9 10 11 Account ID 6274 2843 2892 8837 1892 9523 3165 3924 6023 5290 8529 1144 First Name James Marcus Maureen Debra Mary Bruce John Simon John George Ellen Donald Last Name Johnson Wilson Albright Douglas Smith Gold Carlson Becker Edgar Truman Fairchild Williams Balance 415.56 9217.23 51462.56 27.26 918.26 719.32 1496.24 386.85 9.65 16110.68 86.77 4114.26 Each record in the accounts database is assigned a record number based on that record's relative position within the database file. You could use a record number to retrieve a record directly, much as you can use an array index to reference an array data item directly. Record numbers are assigned by the database file mechanism and are not part od the account information. As a result. They are not meaningful to database users. These users require a different record retrieval mechanism, one that is based on an account ID (the key for the database) rather than a record number. Retrievals based on account ID require an index that associates each account ID with the corresponding record number. You cam implement this index using a binary search tree in which each data item contains the two fields: an account ID (the key) and a record number. struct IndexEntry A database is a collection of related pieces of information that is organized for easy retrieval. The set of accounts records shown below (named "accounts.dat"), for instance, form an accounts database. Record# 0 1 2 3 4 5 6 7 8 9 10 11 Account ID 6274 2843 2892 8837 1892 9523 3165 3924 6023 5290 8529 1144 First Name James Marcus Maureen Debra Mary Bruce John Simon John George Ellen Donald Last Name Johnson Wilson Albright Douglas Smith Gold Carlson Becker Edgar Truman Fairchild Williams Balance 415.56 9217.23 51462.56 27.26 918.26 719.32 1496.24 386.85 9.65 16110.68 86.77 4114.26 Each record in the accounts database is assigned a record number based on that record's relative position within the database file. You could use a record number to retrieve a record directly, much as you can use an array index to reference an array data item directly. Record numbers are assigned by the database file mechanism and are not part od the account information. As a result. They are not meaningful to database users. These users require a different record retrieval mechanism, one that is based on an account ID (the key for the database) rather than a record number. Retrievals based on account ID require an index that associates each account ID with the corresponding record number. You cam implement this index using a binary search tree in which each data item contains the two fields: an account ID (the key) and a record number. struct IndexEntry