Performance improvement in OpenOffice.org

1. Niklas Nebel Sun Microsystems PERFORMANCE IMPROVEMENTS IN CALC

3. Local optimizations

4. Handling sheets separately

5. DataPilot performance

6. Load & save outlook

7. Introduction and Context

10. Recalculation: Up to 20 times faster (extreme case)

11. Local Optimizations

13. Single quote character added if text can be parsed as a number

14. Unnecessary parsing step

15. Can take up to 17% of CPU time

17. File format: XML Schema dates ( ≈ ISO 8601)

20. 10% of CPU time if only date cells are used

22. Keep a list of ranges for each set of formats

25. Operators, separators, parentheses are not

27. Use std::nth_element STL method instead

28. Faster calculation after loading

30. Parameter range can contain several changed cells

32. Extreme case: Issue 95967 – 20x faster

33. Handling Sheets Separately

36. Others as needed (display, printing, …)

39. Row heights can be updated later

41. Little improvement for text and numbers

42. 30% CPU time with date cells on many sheets

43. Formula results don't have to be calculated

45. Copy unchanged parts on stream level

47. CPU: Uncompress

51. 30 – 50% improvement in total time

56. Formula calculation for changed results

57. Cell format changes

58. Column widths or row heights

62. Collect styles for unchanged sheets first

69. Type of sheet content

72. On top of other changes

74. Range dependency registered in all affected slots

77. DataPilot Performance

81. Combination of large fields no longer a limitation

82. Load & Save Outlook

85. Filling DOM tree uses 2% of CPU time

87. But: Memory usage twice the XML stream size

89. Parse XML fragment from stream, or use DOM

92. Q & A

93. PERFORMANCE IMPROVEMENTS IN CALC Niklas Nebel [email_address]