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pmasl 7cb921b545 Updated IQP notebook demos

2019-11-03 16:09:56 -08:00

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Scalar UDF Inlining

User-Defined Functions that are implemented in Transact-SQL and return a single data value are referred to as T-SQL Scalar User-Defined Functions. T-SQL UDFs are an elegant way to achieve code reuse and modularity across SQL queries. Some computations (such as complex business rules) are easier to express in imperative UDF form. UDFs help in building up complex logic without requiring expertise in writing complex SQL queries. Scalar UDF inlining, a feature the Intelligent Query Processing suite of features. This feature improves the performance of queries that invoke scalar UDFs in SQL Server (starting with SQL Server 2019).

This example will show you how upgrading to Database Compatibility Level 150 could improve performance of queries which leverage scalar UDFs. More information about this feature is available here.

Step 1: Setup WideWorldImportersDW database

You could choose to use a container to evaluate this feature. Create an instance of SQL Server 2019 using a Docker image and restore the WideWorldImportersDW database backup

You will need the WideWorldImportersDW database for this exercise. If you don't have this sample database, then you download the sample database here.

Restore the copied WideWorldImportersDW database backup into the container and restore the backup.

Docker Commands

docker pull mcr.microsoft.com/mssql/server:2019-latest

docker run -e "ACCEPT_EULA=Y" -e "SA_PASSWORD=`<A Strong Password`>" -p 1445:1433 --name sql2019demo -d mcr.microsoft.com/mssql/server:2019-latest

docker cp ".\Downloads\WideWorldImportersDW-Full.bak" sql2019demo:/var/opt/mssql/data

Note: For Linux installations the default path to use is /var/opt/mssql

In [7]:

USE [master]
GO
IF EXISTS (SELECT [database_id] FROM sys.databases WHERE [name] = 'WideWorldImportersDW')
ALTER DATABASE [WideWorldImportersDW] SET SINGLE_USER WITH ROLLBACK IMMEDIATE
GO

DECLARE @datafilepath VARCHAR(8000) = CAST(SERVERPROPERTY('InstanceDefaultDataPath') AS VARCHAR(4000)) + 'WideWorldImportersDW.mdf'
DECLARE @logfilepath VARCHAR(8000) = CAST(SERVERPROPERTY('InstanceDefaultLogPath') AS VARCHAR(4000)) + 'WideWorldImportersDW.ldf'
DECLARE @inmemfilepath VARCHAR(8000) = CAST(SERVERPROPERTY('InstanceDefaultDataPath') AS VARCHAR(4000)) + 'WideWorldImportersDW_InMemory_Data_1'
DECLARE @secondaryfilepath VARCHAR(8000) = CAST(SERVERPROPERTY('InstanceDefaultDataPath') AS VARCHAR(4000))+ 'WideWorldImportersDW_2.ndf'

-- Change @backupfile file path as needed
DECLARE @backupfile VARCHAR(8000) = 'E:\SampleDBs\WideWorldImportersDW-Full.bak'
RESTORE DATABASE WideWorldImportersDW
FROM DISK = @backupfile 
WITH MOVE 'WWI_Primary' TO @datafilepath,
    MOVE 'WWI_UserData' TO @secondaryfilepath,
    MOVE 'WWIDW_InMemory_Data_1' TO @inmemfilepath,
    MOVE 'WWI_Log' TO @logfilepath, NOUNLOAD, REPLACE, STATS = 10
GO

USE [master]
GO
ALTER DATABASE [WideWorldImportersDW] MODIFY FILE ( NAME = N'WWI_Log', SIZE = 4GB )
GO

Step 2: Enlarge the WideWorldImportersDW database

In [3]:

USE WideWorldImportersDW;
GO

/*
Assumes a fresh restore of WideWorldImportersDW
*/

IF OBJECT_ID('Fact.OrderHistory') IS NULL 
BEGIN
    SELECT [Order Key], [City Key], [Customer Key], [Stock Item Key], [Order Date Key], [Picked Date Key], [Salesperson Key], [Picker Key], [WWI Order ID], [WWI Backorder ID], Description, Package, Quantity, [Unit Price], [Tax Rate], [Total Excluding Tax], [Tax Amount], [Total Including Tax], [Lineage Key]
    INTO Fact.OrderHistory
    FROM Fact.[Order];
END;

ALTER TABLE Fact.OrderHistory
ADD CONSTRAINT PK_Fact_OrderHistory PRIMARY KEY NONCLUSTERED ([Order Key] ASC, [Order Date Key] ASC) WITH (DATA_COMPRESSION = PAGE);
GO

CREATE INDEX IX_Stock_Item_Key
ON Fact.OrderHistory ([Stock Item Key])
INCLUDE(Quantity)
WITH (DATA_COMPRESSION = PAGE);
GO

CREATE INDEX IX_OrderHistory_Quantity
ON Fact.OrderHistory ([Quantity])
INCLUDE([Order Key])
WITH (DATA_COMPRESSION = PAGE);
GO

CREATE INDEX IX_OrderHistory_CustomerKey
ON Fact.OrderHistory([Customer Key])
INCLUDE ([Total Including Tax])
WITH (DATA_COMPRESSION = PAGE);
GO

IF (SELECT COUNT(*) FROM [Fact].[OrderHistory]) < 3702592
BEGIN
	DECLARE @i smallint
	SET @i = 0
	WHILE @i < 4
	BEGIN
		INSERT INTO [Fact].[OrderHistory] ([City Key], [Customer Key], [Stock Item Key], [Order Date Key], [Picked Date Key], [Salesperson Key], [Picker Key], [WWI Order ID], [WWI Backorder ID], Description, Package, Quantity, [Unit Price], [Tax Rate], [Total Excluding Tax], [Tax Amount], [Total Including Tax], [Lineage Key])
		SELECT [City Key], [Customer Key], [Stock Item Key], [Order Date Key], [Picked Date Key], [Salesperson Key], [Picker Key], [WWI Order ID], [WWI Backorder ID], Description, Package, Quantity, [Unit Price], [Tax Rate], [Total Excluding Tax], [Tax Amount], [Total Including Tax], [Lineage Key]
		FROM [Fact].[OrderHistory];

		SET @i = @i +1
	END;
END
GO

IF OBJECT_ID('Fact.OrderHistoryExtended') IS NULL 
BEGIN
    SELECT [Order Key], [City Key], [Customer Key], [Stock Item Key], [Order Date Key], [Picked Date Key], [Salesperson Key], [Picker Key], [WWI Order ID], [WWI Backorder ID], Description, Package, Quantity, [Unit Price], [Tax Rate], [Total Excluding Tax], [Tax Amount], [Total Including Tax], [Lineage Key]
    INTO Fact.OrderHistoryExtended
    FROM Fact.[OrderHistory];
END;

ALTER TABLE Fact.OrderHistoryExtended
ADD CONSTRAINT PK_Fact_OrderHistoryExtended PRIMARY KEY NONCLUSTERED ([Order Key] ASC, [Order Date Key] ASC)
WITH (DATA_COMPRESSION = PAGE);
GO

CREATE INDEX IX_Stock_Item_Key
ON Fact.OrderHistoryExtended ([Stock Item Key])
INCLUDE (Quantity);
GO

IF (SELECT COUNT(*) FROM [Fact].[OrderHistory]) < 29620736
BEGIN
	DECLARE @i smallint
	SET @i = 0
	WHILE @i < 3
	BEGIN
		INSERT Fact.OrderHistoryExtended([City Key], [Customer Key], [Stock Item Key], [Order Date Key], [Picked Date Key], [Salesperson Key], [Picker Key], [WWI Order ID], [WWI Backorder ID], Description, Package, Quantity, [Unit Price], [Tax Rate], [Total Excluding Tax], [Tax Amount], [Total Including Tax], [Lineage Key])
		SELECT [City Key], [Customer Key], [Stock Item Key], [Order Date Key], [Picked Date Key], [Salesperson Key], [Picker Key], [WWI Order ID], [WWI Backorder ID], Description, Package, Quantity, [Unit Price], [Tax Rate], [Total Excluding Tax], [Tax Amount], [Total Including Tax], [Lineage Key]
		FROM Fact.OrderHistoryExtended;

		SET @i = @i +1
	END;
END
GO

UPDATE Fact.OrderHistoryExtended
SET [WWI Order ID] = [Order Key];
GO

-- Repeat the following until log shrinks. These demos don't require much log space.
CHECKPOINT
GO
DBCC SHRINKFILE (N'WWI_Log' , 0, TRUNCATEONLY)
GO
SELECT * FROM sys.dm_db_log_space_usage
GO

Step 3: Create a T-SQL Scalar UDF

In [4]:

USE [WideWorldImportersDW];
GO

CREATE OR ALTER FUNCTION dbo.ufn_customer_category(@CustomerKey INT) 
RETURNS CHAR(10) AS
BEGIN
    DECLARE @total_amount DECIMAL(18,2);
    DECLARE @category CHAR(10);

    SELECT @total_amount = 
    SUM([Total Including Tax]) 
    FROM [Fact].[OrderHistory]
    WHERE [Customer Key] = @CustomerKey;

    IF @total_amount < 500000
    SET @category = 'REGULAR';
    ELSE IF @total_amount < 1000000
    SET @category = 'GOLD';
    ELSE 
    SET @category = 'PLATINUM';

    RETURN @category;
END
GO

Commands completed successfully.

Total execution time: 00:00:00.027

Step 4: Finding if your T-SQL UDFs is inlineable

In the result set, scroll to the left and notice the value of the is_inlineable column. The value 1 shows that the UDF has inlineable constructs, meaning imperative statements that can be expressed in relational expressions. For example, an IF <expression> ELSE statement can be expressed as an inline SELECT CASE WHEN <expression> THE 1 ELSE 0 END AS <column> statement, or a SET @var = <expression> can be inlined as SELECT <expression> AS var.

The relational expressions for imperative statements handled by the Scalar UDF Inlining feature can be found in the “Froid: Optimization of Imperative Programs in a Relational Database” paper by Microsoft’s Gray Systems Lab in Madison Wisconsin.

In [5]:

USE [WideWorldImportersDW];
GO
SELECT * FROM sys.sql_modules
WHERE object_id = OBJECT_ID('ufn_customer_category')
GO

Out [5]:

Commands completed successfully.

(1 row affected)

Total execution time: 00:00:00.043

object_id	definition	uses_ansi_nulls	uses_quoted_identifier	is_schema_bound	uses_database_collation	is_recompiled	null_on_null_input	execute_as_principal_id	uses_native_compilation	inline_type	is_inlineable
1954106002	CREATE FUNCTION dbo.ufn_customer_category(@CustomerKey INT) RETURNS CHAR(10) AS BEGIN DECLARE @total_amount DECIMAL(18,2); DECLARE @category CHAR(10); SELECT @total_amount = SUM([Total Including Tax]) FROM [Fact].[OrderHistory] WHERE [Customer Key] = @CustomerKey; IF @total_amount < 500000 SET @category = 'REGULAR'; ELSE IF @total_amount < 1000000 SET @category = 'GOLD'; ELSE SET @category = 'PLATINUM'; RETURN @category; END	1	1	0	0	0	0	NULL	0	1	1

Step 5: Execute the query without Scalar UDF Inlining

Even when the database compatibility level is set to the defauult (150), this can be done by using the USE HINT DISABLE_TSQL_SCALAR_UDF_INLINING query hint to disable the feature.

In [3]:

USE [WideWorldImportersDW];
GO
ALTER DATABASE [WideWorldImportersDW] SET COMPATIBILITY_LEVEL = 150;
GO
ALTER DATABASE SCOPED CONFIGURATION CLEAR PROCEDURE_CACHE;
GO

SELECT TOP 100 [Customer Key], [Customer],
       dbo.ufn_customer_category([Customer Key]) AS [Discount Price]
FROM [Dimension].[Customer]
ORDER BY [Customer Key]
OPTION (RECOMPILE,USE HINT('DISABLE_TSQL_SCALAR_UDF_INLINING'));
GO

Out [3]:

Commands completed successfully.

(100 rows affected)

Total execution time: 00:00:09.630

Customer Key	Customer	Discount Price
0	Unknown	PLATINUM
1	Tailspin Toys (Head Office)	PLATINUM
2	Tailspin Toys (Sylvanite, MT)	PLATINUM
3	Tailspin Toys (Peeples Valley, AZ)	PLATINUM
4	Tailspin Toys (Medicine Lodge, KS)	PLATINUM
5	Tailspin Toys (Gasport, NY)	PLATINUM
6	Tailspin Toys (Jessie, ND)	PLATINUM
7	Tailspin Toys (Frankewing, TN)	PLATINUM
8	Tailspin Toys (Bow Mar, CO)	PLATINUM
9	Tailspin Toys (Netcong, NJ)	PLATINUM
10	Tailspin Toys (Wimbledon, ND)	PLATINUM
11	Tailspin Toys (Devault, PA)	PLATINUM
12	Tailspin Toys (Biscay, MN)	PLATINUM
13	Tailspin Toys (Stonefort, IL)	PLATINUM
14	Tailspin Toys (Long Meadow, MD)	PLATINUM
15	Tailspin Toys (Batson, TX)	PLATINUM
16	Tailspin Toys (Coney Island, MO)	PLATINUM
17	Tailspin Toys (East Fultonham, OH)	PLATINUM
18	Tailspin Toys (Goffstown, NH)	PLATINUM
19	Tailspin Toys (Lemeta, AK)	PLATINUM
20	Tailspin Toys (College Place, WA)	PLATINUM
21	Tailspin Toys (Tresckow, PA)	PLATINUM
22	Tailspin Toys (Ward Ridge, FL)	PLATINUM
23	Tailspin Toys (Ikatan, AK)	PLATINUM
24	Tailspin Toys (Dundarrach, NC)	PLATINUM
25	Tailspin Toys (Avenal, CA)	PLATINUM
26	Tailspin Toys (Hedrick, IA)	PLATINUM
27	Tailspin Toys (Bowlus, MN)	PLATINUM
28	Tailspin Toys (North Ridge, NY)	PLATINUM
29	Tailspin Toys (Eulaton, AL)	PLATINUM
30	Tailspin Toys (Koontzville, WA)	PLATINUM
31	Tailspin Toys (Lake Stevens, WA)	PLATINUM
32	Tailspin Toys (Maypearl, TX)	PLATINUM
33	Tailspin Toys (Boyden Arbor, SC)	PLATINUM
34	Tailspin Toys (Dallardsville, TX)	PLATINUM
35	Tailspin Toys (Slanesville, WV)	PLATINUM
36	Tailspin Toys (Ekron, KY)	PLATINUM
37	Tailspin Toys (Kerby, OR)	PLATINUM
38	Tailspin Toys (Airport Drive, MO)	PLATINUM
39	Tailspin Toys (Diablock, KY)	PLATINUM
40	Tailspin Toys (Impact, TX)	PLATINUM
41	Tailspin Toys (Olivette, MO)	PLATINUM
42	Tailspin Toys (Arietta, NY)	PLATINUM
43	Tailspin Toys (Upper Preston, WA)	PLATINUM
44	Tailspin Toys (Amanda Park, WA)	PLATINUM
45	Tailspin Toys (Severna Park, MD)	PLATINUM
46	Tailspin Toys (Jemison, AL)	PLATINUM
47	Tailspin Toys (Lake Hughes, CA)	PLATINUM
48	Tailspin Toys (Trentwood, WA)	PLATINUM
49	Tailspin Toys (Muir, MI)	PLATINUM
50	Tailspin Toys (Hambleton, WV)	PLATINUM
51	Tailspin Toys (Imlaystown, NJ)	PLATINUM
52	Tailspin Toys (Idria, CA)	PLATINUM
53	Tailspin Toys (Nanafalia, AL)	PLATINUM
54	Tailspin Toys (Railroad, PA)	PLATINUM
55	Tailspin Toys (Gum Branch, GA)	PLATINUM
56	Tailspin Toys (Royal City, WA)	PLATINUM
57	Tailspin Toys (Lakemore, OH)	PLATINUM
58	Tailspin Toys (Mappsburg, VA)	PLATINUM
59	Tailspin Toys (Edgartown, MA)	PLATINUM
60	Tailspin Toys (East Dailey, WV)	PLATINUM
61	Tailspin Toys (Fairfield Glade, TN)	PLATINUM
62	Tailspin Toys (Great Neck Estates, NY)	PLATINUM
63	Tailspin Toys (Stallion Springs, CA)	PLATINUM
64	Tailspin Toys (Hodgdon, ME)	PLATINUM
65	Tailspin Toys (North Cowden, TX)	PLATINUM
66	Tailspin Toys (Madaket, MA)	PLATINUM
67	Tailspin Toys (Sentinel Butte, ND)	PLATINUM
68	Tailspin Toys (Gardere, LA)	PLATINUM
69	Tailspin Toys (Lytle Creek, CA)	PLATINUM
70	Tailspin Toys (New Baden, IL)	PLATINUM
71	Tailspin Toys (Good Hart, MI)	PLATINUM
72	Tailspin Toys (Cortaro, AZ)	PLATINUM
73	Tailspin Toys (Cokato, MN)	PLATINUM
74	Tailspin Toys (Indios, PR)	PLATINUM
75	Tailspin Toys (Windsor Locks, CT)	PLATINUM
76	Tailspin Toys (Yewed, OK)	PLATINUM
77	Tailspin Toys (Hahira, GA)	PLATINUM
78	Tailspin Toys (Sekiu, WA)	PLATINUM
79	Tailspin Toys (Page City, KS)	PLATINUM
80	Tailspin Toys (Valdese, NC)	PLATINUM
81	Tailspin Toys (Big Moose, NY)	PLATINUM
82	Tailspin Toys (La Cueva, NM)	PLATINUM
83	Tailspin Toys (Absecon, NJ)	PLATINUM
84	Tailspin Toys (Aceitunas, PR)	PLATINUM
85	Tailspin Toys (Andrix, CO)	PLATINUM
86	Tailspin Toys (New Lexington, OH)	PLATINUM
87	Tailspin Toys (Sauquoit, NY)	PLATINUM
88	Tailspin Toys (Dracut, MA)	PLATINUM
89	Tailspin Toys (Victory Gardens, NJ)	PLATINUM
90	Tailspin Toys (Tolna, ND)	PLATINUM
91	Tailspin Toys (Alstead, NH)	PLATINUM
92	Tailspin Toys (Sans Souci, SC)	PLATINUM
93	Tailspin Toys (Clewiston, FL)	PLATINUM
94	Tailspin Toys (Cheyenne Wells, CO)	PLATINUM
95	Tailspin Toys (Lavon, TX)	PLATINUM
96	Tailspin Toys (South La Paloma, TX)	PLATINUM
97	Tailspin Toys (Manchester Center, VT)	PLATINUM
98	Tailspin Toys (El Centro, CA)	PLATINUM
99	Tailspin Toys (Guin, AL)	PLATINUM

Observe the query execution plan (or actual plan).

Notice the simplicity of the plan and estimated cost percentage for each operator. There is no cost estimated for the Compute Scalar because these are not realistically costed.

The iterative invocation nature of the UDF is also obfuscated from the plan:

Possibly complex logic that may be inside the UDF is not surfaced to the plan.
The time spent in a scalar UDF invocation is also not surfaced in the Compute Scalar. As seen in the QueryTimeStats property of the SELECT, the UDF was responsible for the bulk of the elasped and CPU time in this query's execution, and at first glance that CPU cost is not identifiable in the plan.

Also note that the plan was executed serially. Scalar UDFs are parallelism inhibitors.

Step 4: Execute the query by removing any hint restriction

Run the same query from Step 3, but now without any hint, allowing SQL Server to operate as default.

In [5]:

USE [WideWorldImportersDW];
GO
ALTER DATABASE [WideWorldImportersDW] SET COMPATIBILITY_LEVEL = 150;
GO
ALTER DATABASE SCOPED CONFIGURATION CLEAR PROCEDURE_CACHE;
GO

SELECT TOP 100 [Customer Key], [Customer],
       dbo.ufn_customer_category([Customer Key]) AS [Discount Price]
FROM [Dimension].[Customer]
ORDER BY [Customer Key]
OPTION (RECOMPILE);
GO

Out [5]:

Commands completed successfully.

(100 rows affected)

Total execution time: 00:00:01.089

Customer Key	Customer	Discount Price
0	Unknown	PLATINUM
1	Tailspin Toys (Head Office)	PLATINUM
2	Tailspin Toys (Sylvanite, MT)	PLATINUM
3	Tailspin Toys (Peeples Valley, AZ)	PLATINUM
4	Tailspin Toys (Medicine Lodge, KS)	PLATINUM
5	Tailspin Toys (Gasport, NY)	PLATINUM
6	Tailspin Toys (Jessie, ND)	PLATINUM
7	Tailspin Toys (Frankewing, TN)	PLATINUM
8	Tailspin Toys (Bow Mar, CO)	PLATINUM
9	Tailspin Toys (Netcong, NJ)	PLATINUM
10	Tailspin Toys (Wimbledon, ND)	PLATINUM
11	Tailspin Toys (Devault, PA)	PLATINUM
12	Tailspin Toys (Biscay, MN)	PLATINUM
13	Tailspin Toys (Stonefort, IL)	PLATINUM
14	Tailspin Toys (Long Meadow, MD)	PLATINUM
15	Tailspin Toys (Batson, TX)	PLATINUM
16	Tailspin Toys (Coney Island, MO)	PLATINUM
17	Tailspin Toys (East Fultonham, OH)	PLATINUM
18	Tailspin Toys (Goffstown, NH)	PLATINUM
19	Tailspin Toys (Lemeta, AK)	PLATINUM
20	Tailspin Toys (College Place, WA)	PLATINUM
21	Tailspin Toys (Tresckow, PA)	PLATINUM
22	Tailspin Toys (Ward Ridge, FL)	PLATINUM
23	Tailspin Toys (Ikatan, AK)	PLATINUM
24	Tailspin Toys (Dundarrach, NC)	PLATINUM
25	Tailspin Toys (Avenal, CA)	PLATINUM
26	Tailspin Toys (Hedrick, IA)	PLATINUM
27	Tailspin Toys (Bowlus, MN)	PLATINUM
28	Tailspin Toys (North Ridge, NY)	PLATINUM
29	Tailspin Toys (Eulaton, AL)	PLATINUM
30	Tailspin Toys (Koontzville, WA)	PLATINUM
31	Tailspin Toys (Lake Stevens, WA)	PLATINUM
32	Tailspin Toys (Maypearl, TX)	PLATINUM
33	Tailspin Toys (Boyden Arbor, SC)	PLATINUM
34	Tailspin Toys (Dallardsville, TX)	PLATINUM
35	Tailspin Toys (Slanesville, WV)	PLATINUM
36	Tailspin Toys (Ekron, KY)	PLATINUM
37	Tailspin Toys (Kerby, OR)	PLATINUM
38	Tailspin Toys (Airport Drive, MO)	PLATINUM
39	Tailspin Toys (Diablock, KY)	PLATINUM
40	Tailspin Toys (Impact, TX)	PLATINUM
41	Tailspin Toys (Olivette, MO)	PLATINUM
42	Tailspin Toys (Arietta, NY)	PLATINUM
43	Tailspin Toys (Upper Preston, WA)	PLATINUM
44	Tailspin Toys (Amanda Park, WA)	PLATINUM
45	Tailspin Toys (Severna Park, MD)	PLATINUM
46	Tailspin Toys (Jemison, AL)	PLATINUM
47	Tailspin Toys (Lake Hughes, CA)	PLATINUM
48	Tailspin Toys (Trentwood, WA)	PLATINUM
49	Tailspin Toys (Muir, MI)	PLATINUM
50	Tailspin Toys (Hambleton, WV)	PLATINUM
51	Tailspin Toys (Imlaystown, NJ)	PLATINUM
52	Tailspin Toys (Idria, CA)	PLATINUM
53	Tailspin Toys (Nanafalia, AL)	PLATINUM
54	Tailspin Toys (Railroad, PA)	PLATINUM
55	Tailspin Toys (Gum Branch, GA)	PLATINUM
56	Tailspin Toys (Royal City, WA)	PLATINUM
57	Tailspin Toys (Lakemore, OH)	PLATINUM
58	Tailspin Toys (Mappsburg, VA)	PLATINUM
59	Tailspin Toys (Edgartown, MA)	PLATINUM
60	Tailspin Toys (East Dailey, WV)	PLATINUM
61	Tailspin Toys (Fairfield Glade, TN)	PLATINUM
62	Tailspin Toys (Great Neck Estates, NY)	PLATINUM
63	Tailspin Toys (Stallion Springs, CA)	PLATINUM
64	Tailspin Toys (Hodgdon, ME)	PLATINUM
65	Tailspin Toys (North Cowden, TX)	PLATINUM
66	Tailspin Toys (Madaket, MA)	PLATINUM
67	Tailspin Toys (Sentinel Butte, ND)	PLATINUM
68	Tailspin Toys (Gardere, LA)	PLATINUM
69	Tailspin Toys (Lytle Creek, CA)	PLATINUM
70	Tailspin Toys (New Baden, IL)	PLATINUM
71	Tailspin Toys (Good Hart, MI)	PLATINUM
72	Tailspin Toys (Cortaro, AZ)	PLATINUM
73	Tailspin Toys (Cokato, MN)	PLATINUM
74	Tailspin Toys (Indios, PR)	PLATINUM
75	Tailspin Toys (Windsor Locks, CT)	PLATINUM
76	Tailspin Toys (Yewed, OK)	PLATINUM
77	Tailspin Toys (Hahira, GA)	PLATINUM
78	Tailspin Toys (Sekiu, WA)	PLATINUM
79	Tailspin Toys (Page City, KS)	PLATINUM
80	Tailspin Toys (Valdese, NC)	PLATINUM
81	Tailspin Toys (Big Moose, NY)	PLATINUM
82	Tailspin Toys (La Cueva, NM)	PLATINUM
83	Tailspin Toys (Absecon, NJ)	PLATINUM
84	Tailspin Toys (Aceitunas, PR)	PLATINUM
85	Tailspin Toys (Andrix, CO)	PLATINUM
86	Tailspin Toys (New Lexington, OH)	PLATINUM
87	Tailspin Toys (Sauquoit, NY)	PLATINUM
88	Tailspin Toys (Dracut, MA)	PLATINUM
89	Tailspin Toys (Victory Gardens, NJ)	PLATINUM
90	Tailspin Toys (Tolna, ND)	PLATINUM
91	Tailspin Toys (Alstead, NH)	PLATINUM
92	Tailspin Toys (Sans Souci, SC)	PLATINUM
93	Tailspin Toys (Clewiston, FL)	PLATINUM
94	Tailspin Toys (Cheyenne Wells, CO)	PLATINUM
95	Tailspin Toys (Lavon, TX)	PLATINUM
96	Tailspin Toys (South La Paloma, TX)	PLATINUM
97	Tailspin Toys (Manchester Center, VT)	PLATINUM
98	Tailspin Toys (El Centro, CA)	PLATINUM
99	Tailspin Toys (Guin, AL)	PLATINUM

Observe the query execution plan (or actual plan). Notice the plan now inlines the UDF logic, and SQL Server was able to optimize the plan adequately. As you can see from the execution times, the query with Batch Mode for Rowstore finished much faster! From ~9s to ~1s.

Notice the QueryTimeStats property of the SELECT:

The query elapsed and CPU time are identical, which means there is no hidden cost and that is immediately apparent when looking at the plan (for example in the TOP operator. Remember the operator time is cumulative up the plan tree in row mode execution).
There is no UDF-related execution statistic s, because the UDF was not executed. Instead, its logic was automatically inlined.

93 KiB Raw Blame History

Scalar UDF Inlining

Step 1: Setup WideWorldImportersDW database

Docker Commands

Step 2: Enlarge the WideWorldImportersDW database

Step 3: Create a T-SQL Scalar UDF

Step 4: Finding if your T-SQL UDFs is inlineable

Step 5: Execute the query without Scalar UDF Inlining

Step 4: Execute the query by removing any hint restriction

93 KiB

Raw Blame History