It’s all about the Cardinalities
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4. List tables from the query in the spreadsheet ....................... 47
5. Note the row count for each table ......................................... 49
6. Build and run FILTER QUERIES for each table .................... 50
7. Note the filtered row counts .................................................. 52
8. Compute FILTERED ROWS PERCENTAGE for each table . 52
9. Determine PREFERRED JOIN ORDER ............................... 53
10. Construct a QUERY DIAGRAM .......................................... 54
11. Determine INITIAL JOIN ORDER ........................................ 55
12. Build and run RECONSTRUCTION QUERIES ................... 57
ATT_EMP_ORG Reconstruction Query ....................................................................................... 58
CBE_EMP Reconstruction Query ...................................................................................................... 58
V_CBE_LV_RQST Reconstruction Query ........................................................................................ 58
V_PLCY_DIM Reconstruction Query ................................................................................................ 59
V_LV_PLN_USGE_FACT Reconstruction Query ........................................................................... 60
ATT_LV_TYP (LV_SEG_LV_TYP) Reconstruction Query ............................................................. 61
ATT_LV_PLN_TYP Reconstruction Query ....................................................................................... 62
ATT_LV_PLN Reconstruction Query ................................................................................................. 63
13. Note reconstruction row counts .......................................... 65
14. Use CARDINALITY FEEDBACK to adjust join order .......... 65
15. Repeat (11) thru (12) once if join order changed ................ 65
16. Determine if further action is necessary .............................. 66
Summary #1 .................................................. 69
How to use FILTERED ROWS PERCENTAGE
Method .......................................................... 69
Backtracking on CARDINALITY FEEDBACK 70
14. Use CARDINALITY FEEDBACK to adjust join order .......... 70
15. Repeat (11) through (12) once if join order changed ........... 71
The Short Cut (Brain over Brawn) ................ 73
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