This presentation is prepared for the presentation of thesis titled as "Data compression for Large Multidimensional Data Warehouses" which was done for the partial fulfillment of the undergrad course in Dept of CSE, KUET, Bangladesh.

1. Data Compression for Large Multidimensional Data Warehouses Supervisor: Presented by: Dr. K.M. Azharul Hasan Associate Professor, Head of the Department, Department of CSE, KUET Abdullah Al Mahmud, Roll : 0507006 Md. Mushfiqur Rahman, Roll : 0507029 1 This slide is prepared by Abdullah Al Mahmud for the presentation of Thesis which was done as the partial fulfillment of degree of in undergrad course in Khulna University of Engineering & Technology(KUET), Bangladesh

3. Existing Compression Schemes

4. Traditional Extendible Array

5. Proposed Compression Scheme

7. Conclusion2 Abdullah Al Mahmud, Student ID: 0507006, Dept. of CSE, KUET, Bangladesh

9. effective price of logical data storage capacity

10. improves query performance

11. Multidimensional array is widely used in large number of scientific research.

12. An efficient compression of multidimensional array can handle large multidimensional data sets of data warehouses3 Objectives Abdullah Al Mahmud, Student ID: 0507006, Dept. of CSE, KUET, Bangladesh

14. Run Length Encoding

15. Header compression

16. Compressed Column Storage

17. Compressed Row Storage4 Abdullah Al Mahmud, Student ID: 0507006, Dept. of CSE, KUET, Bangladesh

18. Existing Compression Schemes (2/ 3) 5 (a) A sparse array. (b) The CRS scheme Abdullah Al Mahmud, Student ID: 0507006, Dept. of CSE, KUET, Bangladesh

20. Compressing sparse array

21. Do not support extendibility6 Abdullah Al Mahmud, Student ID: 0507006, Dept. of CSE, KUET, Bangladesh

24. Extendibility of multidimensional arrays

25. A compression technique that can work on multidimensional extendible array

26. Our proposed compression scheme is EXCS (Extendible array based Compression Scheme)8 Abdullah Al Mahmud, Student ID: 0507006, Dept. of CSE, KUET, Bangladesh

28. We have considered dimension =3 in our experimental approach

29. The sub-arrays are distinguished to store them individually in the secondary memory9 Abdullah Al Mahmud, Student ID: 0507006, Dept. of CSE, KUET, Bangladesh

31. A large no. of sub-arrays are generated to be compressed

32. Sub-arrays are dynamically taken as input

33. Only the max no of sub-arrays is to be given10 Abdullah Al Mahmud, Student ID: 0507006, Dept. of CSE, KUET, Bangladesh

35. The compression technique used is similar to CRS

36. The compressed elements are written in the secondary memory as RO, CO, VL of subarray_1, subarray_2, … … subarray_NAbdullah Al Mahmud, Student ID: 0507006, Dept. of CSE, KUET, Bangladesh

38. Data Density

39. Length of Dimension/ Number of Data

41. we have considered space savings in percent12 Abdullah Al Mahmud, Student ID: 0507006, Dept. of CSE, KUET, Bangladesh

42. Comparative Analysis (1/4) 13 No. of data Figure: Comparison with fixed density = 20% Abdullah Al Mahmud, Student ID: 0507006, Dept. of CSE, KUET, Bangladesh

43. 14 Comparative Analysis (2/4) No. of data Figure: Comparison with fixed density = 25% Abdullah Al Mahmud, Student ID: 0507006, Dept. of CSE, KUET, Bangladesh

44. Comparative Analysis (3/4) 15 Density of data Figure: Comparison with fixed no. of data=64 Abdullah Al Mahmud, Student ID: 0507006, Dept. of CSE, KUET, Bangladesh

45. Comparative Analysis (4/4) 16 Density of data Figure: Comparison with fixed no. of data=4096 Abdullah Al Mahmud, Student ID: 0507006, Dept. of CSE, KUET, Bangladesh

47. Using multidimensional arrays

48. Extendibility toward any dimension

49. EXCS allows dynamic extension of arrays.

50. In analysis, we can extend data up to n dimensions

51. Performance is good for large no. of data17 Abdullah Al Mahmud, Student ID: 0507006, Dept. of CSE, KUET, Bangladesh

53. It can be extended experimentally for compressing n dimension data in future.

54. EXCS is effective for large multidimensional data warehouses18 Abdullah Al Mahmud, Student ID: 0507006, Dept. of CSE, KUET, Bangladesh