Database index(sql server)
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The document discusses database indexing, explaining the difference between clustered and nonclustered indexes, as well as concepts like index fragmentation and coverage indexes. It highlights the importance of choosing the right index based on factors such as usage frequency, uniqueness, and data type. Additionally, it provides resources for visualizing index structures and emphasizes the role of statistics in query optimization.
Database index(sql server)
- 2. TOPIC • WHAT IS THE INDEX OF DATABASE SYSTEM • CLUSTERED INDEX VS. NONCLUSTERED INDEX • THE STATISTICS OF INDEX • THE COVERAGE IDNEX • WHAT IS INDEX FRAGMENTATION • CREATE THE RIGHT INDEX
- 3. WHAT IS THE INDEX OF DATABASE SYSTEM
- 4. I want to query customer BIG-Data …5 min …10 min …30 min…20 min BEFORE AFTER
- 5. INDEX IS DECIDED DATA STORAGE STRUCTURE HAS CLUSTERED INDEXNO INDEX
- 6. CLUSTERED INDEX VS. NONCLUSTERED INDEX CLUSTERED INDEX NONCLUSTERED INDEX CL01 Taipei Ken WHERE Country=‘Taipei’ Got it CL Key value CL01 Searching …
- 7. Binary Search Tree (BST) http://visualgo.net/bst.html
- 8. CLUSTERED AND NONCLUSTERED INDEX BASE ON B-TREE
- 9. ANYTHING IS A DOUBLE-EDGED SWORD RECORD INDEX-01 Page-01 INDEX-02 RECORD001 PG01-RECORD001 PG01-RECORD001 RECORD002 PG01-RECORD002 PG01-RECORD002
- 10. BE CAREFUL INCREASE THE INDEX
- 11. THE STATISTICS OF INDEX
- 12. IT’S IMPORTANT FOR SQL TO GUESS YOUR QUERY RESULT NUMBER
- 13. DEMO
- 15. INCLUDE EVERYTHING YOU USED SELECT COLUMN JOIN COLUMN WHERE CONDITION COLUMN
- 16. DEMO
- 17. WHAT IS INDEX FRAGMENTATION
- 19. DEMO
- 20. CREATE THE RIGHT INDEX
- 21. PRINCIPLE FREQUENTLY USED COLUMNS COLUMN UNIQUENESS COLUMN DATA TYPE
Editor's Notes
- #12: DBCC SHOW_STATISTICS(‘{TABLE_NAME}’,’{INDEX_NAME’)