Q U E R Y S T O R E I N

S Q L S E R V E R 2 0 1 6

A TO U R O F N E W F E AT U R E S

Ahsan Kabir

MVP on Data Platform

“techforum” user group Meetup

WHAT

Query store has introduced in SQL Server 2016 for simplification of

performance troubleshooting process. Queries having multiple plans:

identify un-efficient plans and force a better plan.

Query store stores the insight information of queries i.e.

history of queries,

plans, and

runtime statistics,

resource usage patterns

database usage patterns

query plan and

regressing queries.

WHY• Explore the queries execution

• Resource consuming queries

• Figure out query plan

• Identify possible performance degradation queries

• Figure out why regressions happen

• Force the query processor to use a particular plan

• Query Store is accessible through Transact-SQL.

• Identify and improve ad-hoc workloads

• Pinpoint and fix queries

• Custom reporting and/or alerting through

Dynamic Management Views (DMVs)

HOWStep :1 Query Compilation

SQL Server compiles a query > Compile message >Store into Query Store with execution plan

Step :2 Execution Time

Query is execution > Execute message >Store into Query Store with run time statistics

Step :3 Post execution

After Execution >Query Store aggregates the information in Memory

>Aggregated data will be asynchronously store into primary file group

ConfigureQueryStore

QueryData Store

Let’s Find &

Tune

STEP’S

S te

p1: E

nab

le Q

uery

Sto

re

Management Studio

Management Studio >Object Explorer >Right-click a database>Properties >Set Enable =True

Transact-SQL Statements

“ALTER DATABASE AdventureWorks2016CTP3 SET QUERY_STORE = ON;”

Step 2

: Configu

ration u

sing

SSM

S Operation Mode :Available option Off, Read Write or Read. In Read mode no new Execution Plans or query runtime statistics will be collected.

Data Flush Interval (Minutes): being flushed from memory to disk.

Statistics Collection Interval:It set the aggregation interval of query runtime statistics inside the Query Store.Max Size (MB) indicate maximum size of Query Store.

Query Store Capture Mode All capture all queriesAuto Base on resources consumption.None stop capturing Size Based Cleanup Mode Activate data cleanup automatically when data reach at Max size.Off Data cleanup don’t take place

Auto Data cleanup happens automaticallyStale Query Threshold (Days) Sets how long query data is retained inside the Query Store. By default the setting is configured to 367 days.

Step 3

: C

onfigu

re u

sin

g T

-SQ

L

ALTER DATABASE AdventureWorks2016CTP3

SET QUERY_STORE = ON(OPERATION_MODE = READ_WRITE,

CLEANUP_POLICY = (STALE_QUERY_THRESHOLD_DAYS = 10),DATA_FLUSH_INTERVAL_SECONDS = 5000,MAX_STORAGE_SIZE_MB = 1000,INTERVAL_LENGTH_MINUTES = 10,SIZE_BASED_CLEANUP_MODE = AUTO,QUERY_CAPTURE_MODE = AUTO,MAX_PLANS_PER_QUERY = 500

);GO

Query

Sto

re c

onta

iner

in S

SM

S

SSMS view Scenario

Regressed

Queries

Pinpoint queries for which execution

metrics have recently regressed (i.e.

changed to worse).

Top Resource

Consuming

Queries

Queries which have the biggest impact to

database resource consumption.

Tracked Queries

when you have queries with forced plans

and you want to make sure that query

performance is stable.

Overall Resource

Consumption

Analyze the total resource consumption

for the database. Use this view to identify

resource patterns (daily vs. nightly

workloads) and optimize overall

consumption for your database.

Step 1

: Pin

poin

t an

d fix

Regressed Queries :

Object Explorer >Select Database >Query Store >Regressed Queries

T H A N K S

H AV E A N I C E D AY