Question

Problem 1. Consider a disk with block size B=1024 bytes. A block pointer is P = 8 bytes long, and a record pointer is R =7 bytes long. A file has r=5,000,000 EMPLOYEE records of fixed- length. Each record has the following fields: NAME (30 bytes), SSN (9 bytes), DEPARTMENTCODE (9 bytes), ADDRESS (35 bytes), PHONE (9 bytes), BIRTHDATE (8 bytes), SEX (1 byte), JOBCODE (4 bytes), SALARY (4 bytes, real number). An additional byte is used as a deletion marker. (a) Calculate the record size Rin bytes. (b) Calculate the blocking factor bfr and the number of file blocks b assuming an unspanned organization where records are not allowed to cross block boundaries. (An unspanned organization enforces the rule that no record spans more than one block) (c) Suppose the file is ordered by the key field SSN and we want to construct a primary index on SSN. Calculate (i) the index blocking factor bfri (which is also the index fan-out); (ii) the number of first-level index entries and the number of first-level index blocks; (iii) the number of levels needed if we make it into a multi-level index; (iv) the minimum number of blocks required by the multi-level index; (v) the number of block accesses needed to search for and retrieve a record from the file--given its SSN value--using the primary index.

Answer 1

@ R * Record size() in bytes R = Name Gobytes) +ss Nabytes) +Deptbede (abytes)+ addoos (35 bytes) +bhome abytes) + Birthdate (a bytet sex(ibyte) + Job Code (ubyte) + Salany (ubytest Dete tiommarken (byte) =) 30+9+9+35+9+8+1+4+4+1 - 110 bytes b)Ô Blocking factor (ba) Block length =1024 Blocking factors = Floos Block length) - floobay/o) -9 Coeconds pret block) bfx = 9 (as it is unstainnal organisation, a recoods Can be fil in a block) C No. of file blocks - No. of records - 5000,000 No of records in a block -9 No of file blocks: lie of blouet required to en store this file) -> Ceiling (5000 coola) ->555556