You can watch the replay for this IDERA Live webcast in the IDERA Resource Center: https://www.idera.com/resourcecentral/webcasts/modern-query-optimizer Data changes happen quickly—and the DBA can’t easily monitor query performance 24/7. In recent releases SQL Server has introduced a number of new features to improve query performance in the event of performance degradation. In this session you will get an overview of the new additions and how they can help their workloads and improve your execution plans. You will learn about how the SQL Server query optimizer has changed to make adaptive decisions at query execution, and has changed some former anti-patterns. This session will focus on SQL Server 2019, but will highlight some changes introduced in SQL Server 2017. Speaker: Joey D'Antoni is a Senior Consultant and SQL Server MVP with over a decade of experience working in both Fortune 500 and smaller firms. He is a Principal Architect for Denny Cherry and Associates and lives in Malvern, PA. He is a frequent speaker at major tech events, and blogger about all topics technology. He believes that no single platform is the answer to all technology problems. He holds a BS in Computer Information Systems from Louisiana Tech University and an MBA from North Carolina State University, and is the co-author of the Microsoft white paper "Using Power BI in a Hybrid Environment.”

1. 1© 2016 IDERA, Inc. All rights reserved. Proprietary and confidential.© 2020 IDERA, Inc. All rights reserved. 1
Take Advantage of SQL Server 2019 and Beyond
Joey D’Antoni
Principal Consultant, Denny Cherry and Associates Consulting
The Modern Query Optimizer

2. Joey D’Antoni
Joey has over 20 years of
experience with a wide variety of
data platforms, in both Fortune
50 companies as well as smaller
organizations
He is a frequent speaker on
database administration, big
data, and career management
MVP, MCSE BI and Data
Platform
VMWare vExpert
He wants you to make sure you
can restore your data

3. © 2016 IDERA, Inc. All rights reserved. Proprietary and confidential.© 2020 IDERA, Inc. All rights reserved. 3
The Query Optimizer
The Query
Optimizer takes a
query and returns a
query plans
Will attempt several
plans to choose the
”best guess”
Generating a plan
has a high CPU
cost, so SQL Server
caches plans

4. © 2016 IDERA, Inc. All rights reserved. Proprietary and confidential.© 2020 IDERA, Inc. All rights reserved.
Caching

5. © 2016 IDERA, Inc. All rights reserved. Proprietary and confidential.© 2020 IDERA, Inc. All rights reserved.
Plan Cache
Also known as
procedure cache
Once a plan is
generated it is
cached in the plan
cache
Optimize for ad-
hoc workloads

6. © 2016 IDERA, Inc. All rights reserved. Proprietary and confidential.© 2020 IDERA, Inc. All rights reserved.
Parameters

7. © 2016 IDERA, Inc. All rights reserved. Proprietary and confidential.© 2020 IDERA, Inc. All rights reserved.
Some Common Problems
Parameter Sniffing leading
to poor plan choices
Query constructs that have
poor optimizer estimates
Scalar Functions

8. © 2020 IDERA, Inc. All rights reserved.
Intelligent Query Processing
Performance insights anytime and anywhere
with Lightweight Query Profiling
Sequential Key Insert Performance
In-Memory Database
• Hybrid Buffer Pool
• Memory-Optimized TempDB Metadata
• In-Memory OLTP
• Persistent Memory Support
Intelligent Performance
with SQL Server
The intelligent database
Gain performance without
changing the application
The Intelligent Query Processing feature family
Intelligent QP
Adaptive QP
Adaptive Joins
Batch Mode
Interleaved
Execution
Memory Grant
Feedback
Row ModeBatch Mode
Table Variable
Deferred Compilation
Approximate QP
Approximate
Count Distinct
Batch Mode for
Row Store
Scalar UDF
inlining

9. © 2016 IDERA, Inc. All rights reserved. Proprietary and confidential.© 2020 IDERA, Inc. All rights reserved. 9
Intelligent Query Processing
The Solution(s)
• Build intelligent, adaptable
operators
• Modify query plans in cache
based on previous execution
• Expand batch mode
• Execution data drives
downstream compilation
• Smarter query processing
140
140
140
150
150
150
140 SQL Server 2017
150 SQL Server 2019
150

10. 10© 2016 IDERA, Inc. All rights reserved. Proprietary and confidential.© 2020 IDERA, Inc. All rights reserved. 10
▪ SQL Server 2019
Demo

11. © 2016 IDERA, Inc. All rights reserved. Proprietary and confidential.© 2020 IDERA, Inc. All rights reserved.
Summary
Query Optimization is a challenging art and science
SQL Server is improving this process over time
Compatibility mode protects and helps you
Take advantage of the features that are in the engine

12. © 2016 IDERA, Inc. All rights reserved. Proprietary and confidential.© 2020 IDERA, Inc. All rights reserved. 1212
THANKS!
Any questions?
You can find me at:
@jdanton
joey@dcac.com