1. Denis Reznik
SQL Server 2017 Hidden Gems

2. Organizers
Natalia Pogorelova
Andriy Pogorelov
Paul Stetsenko

3. Sponsors

4. About Me Denis Reznik Kyiv, Ukraine Data Architect at Intapp, Inc.
But Originally from Kharkiv Region
Data Architect at Intapp, Inc.
Microsoft Data Platform MVP
Co-Founder of Ukrainian Data Community Kyiv (PASS Chapter)
PASS Regional Mentor, Central and Eastern Europe
Co-author of “SQL Server MVP Deep Dives vol. 2”

5. SQL Server 2017 Killer Features Hidden Features SQL Server on Linux
Graph Database
QP Improvements
Hidden Features
The most “Hidden” feature of SQL Server 2019
Lightweight Profiling
File System Views
String Aggregation
String Trimming
Version Store Space
Log Statistics
Statistics Update/Create
CXCONSUMER and CXPACKET waits
Functions Troubleshooting
Row Goal
Compatibility Level

6. Hidden Features Importance
STORY
Hidden Features Importance

7. The most “Hidden” feature of SQL Server 2019
DEMO
The most “Hidden” feature of SQL Server 2019

8. Lightweight Profiling

9. Lightweight Profiling
SQL Server 2014 – sys.dm_exec_query_profiles
SQL Server 2016/2014 SP1 – Live Query Statistics
Enable LQS in SSMS
SET STATISTICS XML ON
SET STATISTICS PROFILE ON
query_post_execution_showplan event
SQL Server 2016/2014 SP2 - query_thread_profile event
SQL Server 2016 SP1 – query_thread_profile/TF 7412
Lightweight query execution profiling
SQL Server ?
SQL Server 2019 – Enabled by default
Session Level
Server Level

10. Lightweight Profiling
DEMO
Lightweight Profiling

11. DEMO
File System Views

12. DEMO
String Aggregate

13. DEMO
TRIM

14. Version Store Space

15. Version Store Usage with SNAPSHOT
SELECT * FROM Users
WHERE City = 'Kyiv'
BEGIN TRAN
UPDATE Users
SET City = 'Krakow'
WHERE City = 'Kyiv' ID
City 1
Krakow 2 3 4 5 6
New York 7 ID
City 1
Kyiv 2
Krakow 3 4 5 6
New York 7 X
SELECT * FROM Users
WHERE City = 'Kyiv'
Version Store ID
City 1
Kyiv
tempdb

16. DEMO
Version Store Space

17. Transaction Log Statistics
DEMO
Transaction Log Statistics

18. CXPACKET and CXCONSUMER Waits

19. CXPACKET and CXCONSUMER Waits
DEMO
CXPACKET and CXCONSUMER Waits

20. Parallel Query Execution
Amdal’s Law 2s 1s
Thread 1
Thread 2
Thread 3
Thread 4

21. CX_PACKET (<2017) 2s 1s Thread 0 Thread 1 Thread 2 Thread 3
CXPACKET Wait
CXPACKET Wait
Thread 1
CXPACKET Wait
Thread 2
CXPACKET Wait
Thread 3
Thread 4
CXPACKET Wait

22. CX_PACKET 2017 2s 1s Thread 0 Thread 1 Thread 2 Thread 3 Thread 4
CXCONSUMER Wait
CXCONSUMER Wait
Thread 1
CXPACKET Wait
Thread 2
CXPACKET Wait
Thread 3
Thread 4
CXPACKET Wait

23. Functions Troubleshooting
DEMO
Functions Troubleshooting

24. DEMO
Row Goal

25. QUERY OPTIMIZER COMPATIBILITY LEVEL

26. Statistics SELECT * FROM Users WHERE Id BETWEEN 2100 AND 2500
800
2000
2800
4500
5400

27. Statistics
SELECT * FROM Users u
INNER JOIN Posts p
ON u.Id = p.OwnerUserId
WHERE u.DisplayName LIKE 'Jeff%'
Users A G L S T
ZZZZ
Posts 1
800
2000
2800
4500
5400

28. QUERY OPTIMIZER COMPATIBILITY LEVEL
DEMO
QUERY OPTIMIZER COMPATIBILITY LEVEL

29. SUMMARY
Hidden Features Importance Story Truncation Error Message (the most known “hidden” feature) Lightweight Profiling File System Views String Aggregation String Trimming Version Store Space Log Statistics Statistics Update/Create CXCONSUMER and CXPACKET waits Functions Troubleshooting Row Goal Compatibility Level

30. Sponsors

31. Thank You! Denis Reznik Twitter: @denisreznik
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