1. SQL Server Deep Dive Denis Reznik Data Architect at Intapp

2. About me  Kiev, Ukraine  Data Architect at Intapp Inc.  Microsoft MVP  Leader of Kyiv SQL Server User Group  Co-author of “SQL Server MVP Deep Dives vol. 2”  SoftServe IT-Awards judge 2 |

4. SQL Server Network Interface

5. SQL Server Protocols  Shared Memory  TCP/IP  Named Pipes  VIA (Deprecated)

6. TDS Endpoints TCP/IP Shared Memory Named Pipes VIA DAC TCP/IP Note: TDS – Tabular Data Stream

7. Query Processing

9. Parser  Parse Query Text  Check base SQL syntax  Check if plan is already in cache  Returns ParseTree

10. Algebrizer  Check that objects are exist and available in current execution context  Define types for every node in ParseTree  Returns QueryTree (Logical representation of the query)

11. Optimizer  Goal – get the optimal execution plan Optimizer Query Tree Pre-Optimization Search for trivial plan Load statistics (optional) Simplification – syntax transformation

12. Optimizer Phase 0 Exploration – plan alternatives Return Transaction Processing plan Load statistics

13. Optimizer Phase 1 Next set of query rules Returns Quick Plan Estimate parallel plan (executed twice)

14. Optimizer Phase 2 Full optimization Returns Full Plan Indexed views

15. Index (B-Tree) - Seek … … 1.. 1M 1.. 2K 2K+1.. 4K 1M-2K.. 1M 1.. 300 301..800 801..1,5K 1,5K+1..2K SELECT * FROM Users WHERE Id = 523

16. Index (B-Tree) - Scan … … 1.. 1M 1.. 2K 2K+1.. 4K 1M-2K.. 1M 1.. 300 301..800 801..1,5K 1,5K+1..2K SELECT * FROM Users

17. Index (B-Tree) – Range Scan … … 1.. 1M 1.. 2K 2K+1.. 4K 1M-2K.. 1M 1.. 300 301..800 801..1,5K 1,5K+1..2K SELECT * FROM Users WHERE Id BETWEEN 700 AND 1700

18. Statistics 1800 2000 2800 45005400 SELECT * FROM Users WHERE Id BETWEEN 2100 AND 2500

19. Executor  Execute query using its Query Plan  Ask Storage Engine for data

20. Demo SQL Server, are you kidding me?

21. Storage Engine

22. Buffer Pool Data Cache Database File Access Methods Buffer Manager Select Data

23. Modify Data Buffer Pool Data Cache Database File Access Methods Buffer Manager Transaction Log Log Manager Log Buffer

24. Lock Types - Shared S S S S X X

25. Lock Types - Exclusive X X X X S S

26. Lock Types - Update U U U U S S S S X X

27. Lock Types – Intent locks S S IS

28. S S S S S S … S S 1 2 3 n n = 5000 Table S S if lock can’t be put on table, process will try this every n + 1250 rows 12 Buffer Pool Memory for locks S S > 24% Lock Escalation

29. Demo Use NOLOCK carefully

30. SQL OS

31. Execution model Session Thread Pool Running Suspended Runnable Task(s) SchedulerLogical CPU

32. Demo Worker Threads Starvation

34. @denisreznik denisreznik@live.ru https://www.facebook.com/denis.reznik.5 https://www.linkedin.com/pub/denis-reznik/3/502/234 Thank You!