CS SE 6360 004 Assignment 5 Due Date April 22 2016 11 59 PM 1 Consider a disk with block size B 512 bytes A block pointer is P 6 bytes long and a record pointer is P R 7 bytes long A file has r 3000 EMPLOYEE records of fixed length Each record has the following fields NAME 30 bytes SSN 10 bytes DEPARTMENTCODE 10 bytes ADDRESS 30 bytes PHONE 10 bytes BIRTHDATE 10 bytes GENDER 1 byte JOBCODE 4 bytes SALARY 4 bytes real number An additional byte is used as a deletion marker 50 points a Calculate the record size R in bytes b Calculate the blocking factor bfr and the number of file blocks b assuming an unspanned organization 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 bfr i 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 total number of blocks required by the multi level index and 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 d Suppose the file is not ordered by the key field SSN and we want to construct a secondary index on SSN Repeat the previous exercise part c for the secondary index and compare with the primary index e Suppose the file is not ordered by the non key field DEPARTMENTCODE and we want to construct a secondary index on DEPARTMENTCODE using Option 3 of Section 18 1 3 with an extra level of indirection that stores record pointers Assume there are 100 distinct values of DEPARTMENTCODE and that the EMPLOYEE records are evenly distributed among these values Calculate i the index blocking factor bfr i ii the number of blocks needed by the level of indirection that stores record pointers iii the number of first level index entries and the number of first level index blocks iv the number of levels needed if we make it a multi level index v the total number of blocks required by the multi level index and the blocks used in the extra level of indirection and vi the approximate number of block accesses needed to search for and retrieve all records in the file having a specific DEPARTMENTCODE value using the index f Suppose the file is ordered by the non key field DEPARTMENTCODE and we want to construct a clustering index on DEPARTMENTCODE that uses block anchors every new value of DEPARTMENTCODE starts at the beginning of a new block Assume there are 100 distinct values of DEPARTMENTCODE and that the EMPLOYEE records are evenly distributed among these values Calculate i the index blocking factor bfr i 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 a multi level index iv the total number of blocks required by the multi level index and v the number of block accesses needed to search for and retrieve all records in the file having a specific DEPARTMENTCODE value using the clustering index assume that multiple blocks in a cluster are either contiguous or linked by pointers g Suppose the file is not ordered by the key field Ssn and we want to construct a B tree access structure index on SSN Calculate i the orders p and p leaf of the B tree ii the number of leaf level blocks needed if blocks are approximately 69 full rounded up for convenience iii the number of levels needed if internal nodes are also 69 full rounded up for convenience iv the total number of blocks required by the B tree and v the number of block accesses needed to search for and retrieve a record from the file given its SSN value using the B tree 2 A PARTS file with Part as key field includes records with the following Part values 23 65 37 60 46 92 48 71 56 59 18 21 10 74 78 15 16 20 24 28 39 43 47 50 69 75 8 49 33 38 Suppose the search field values are inserted in the given order in a B tree of order p 4 and p leaf 4 show how the final tree looks like 30 points 3 Optimize the following SQL query on the Company Database to find names of employees earning over 80 000 per year names of projects in which they work more than 30 hours where the project is located in Chicago and the manager of the project s controlling department started after January 1 2009 Select Lname Fname Pname Hours From Project P Employee E Department D Works on W Where E Ssn W Essn and P Dnum D Dnumber and W Pno P Pnumber and Plocation Chicago and Hours 30 and Salary 80000 and Mgr start date 1 1 2009 Show the final query tree 20 points
View Full Document
Unlocking...