SAMPLE DAX Function (Statistical)

Returns a sample subset from a given table expression.

Syntax

SAMPLE ( <Size>, <Table>, <OrderBy> [, [<Order>] [, <OrderBy> [, [<Order>] [, … ] ] ] ] )
Parameter Attributes Description
Size

Number of rows in the sample to be returned.

Table
Iterator

A table expression from which the sample is generated.

OrderBy
Row Context
Repeatable

A scalar expression evaluated for each row of the table.

Order Optional
Repeatable

The order to be applied. 0/FALSE/DESC – descending; 1/TRUE/ASC – ascending.

Return values

Table An entire table or a table with one or more columns.

A table consisting of a sample of Size rows of table or an empty table if Size is 0 (zero) or less.

Remarks

A table consisting of a sample of N rows of table or an empty table if Size is 0 (zero) or less.

One OrderBy argument is required. The returned sample will be stable and deterministic, returning the first row, the last row, and evenly distributed rows between them.

If Size is 0 (zero) or less then SAMPLE returns an empty table.

In order to avoid duplicate values in the sample, the table provided as the second argument should be grouped by the column used for sorting.

Examples

--  SAMPLE returns a given number of rows from a table expression.
--
--  The rows are evenly chosen following the order provided
--  in the third and fourth arguments
DEFINE
    TABLE SampleData = { 2, 4, 4, 4, 5, 5, 7, 9 }
EVALUATE
SAMPLE ( 3, SampleData, [Value], ASC )

EVALUATE
SAMPLE ( 3, SampleData, [Value], DESC )

-- Because SampleData has 8 elements, the elements considered are in position 1, 5, 8
-- The second query returns 5 instead of 4 because the sort order is descending
-- SAMPLE is deterministic when used over the same table with the same argument
Value
2
5
9
Value
9
4
2
--  SAMPLE returns a given number of rows from a table expression.
--  SAMPLE can be used with string columns.
EVALUATE 
    VALUES ( 'Product'[Color] )
ORDER BY [Color] ASC

EVALUATE 
    SAMPLE ( 5, VALUES ( 'Product'[Color] ), 'Product'[Color], ASC )
ORDER BY [Color] ASC

Color
Azure
Black
Blue
Brown
Gold
Green
Grey
Orange
Pink
Purple
Red
Silver
Silver Grey
Transparent
White
Yellow
Color
Azure
Gold
Pink
Silver
Yellow
--  SAMPLE returns a given number of rows from a table expression.
--  SAMPLE can be used with tables.
--  The sort order can be defined by one or more columns.
EVALUATE 
    SAMPLE ( 5, 'Product', 'Product'[Color], ASC, 'Product'[Brand], ASC )
ORDER BY 'Product'[Color] ASC, 'Product'[Brand] ASC

EVALUATE 
    SAMPLE ( 5, 'Product', 'Product'[Brand], ASC, 'Product'[Color], ASC )
ORDER BY 'Product'[Brand] ASC, 'Product'[Color] ASC

-- The results are different because the sort order is by Color and then Brand 
-- in the first query, and by Brand and Color in the second query
ProductKey Product Code Product Name Manufacturer Brand Subcategory Category Color List Price
1030 0401087 A. Datum Slim Digital Camera M180 Azure A. Datum Corporation A. Datum Digital Cameras Cameras and camcorders Azure 148.00
2224 0806035 Adventure Works Chandelier M8150 Blue Adventure Works Adventure Works Lamps Home Appliances Blue 268.50
1598 0602028 SV DVD External DVD Burner M200 Grey Southridge Video Southridge Video Movie DVD Music, Movies and Audio Books Grey 57.88
1739 0702033 MGS RalliSport Challenge E115 Tailspin Toys Tailspin Toys Download Games Games and Toys Silver 28.00
108 0106043 WWI Stereo Bluetooth Headphones New Generation M370 Yellow Wide World Importers Wide World Importers Bluetooth Headphones Audio Yellow 132.99
ProductKey Product Code Product Name Manufacturer Brand Subcategory Category Color List Price
1037 0401094 A. Datum Advanced Digital Camera M300 Azure A. Datum Corporation A. Datum Digital Cameras Cameras and camcorders Azure 188.50
821 0308079 Contoso USB 2.0 Dock Station docking station M800 Grey Contoso, Ltd Contoso Computers Accessories Computers Grey 29.90
1169 0405026 Fabrikam Home and Vacation Moviemaker 1/2” 3mm M300 White Fabrikam, Inc. Fabrikam Camcorders Cameras and camcorders White 566.00
936 0308194 SV 4GB Laptop Memory M65 Black Southridge Video Southridge Video Computers Accessories Computers Black 79.00
108 0106043 WWI Stereo Bluetooth Headphones New Generation M370 Yellow Wide World Importers Wide World Importers Bluetooth Headphones Audio Yellow 132.99

Last update: Apr 2, 2021   » Contribute   » Show contributors

Contributors: Alberto Ferrari, Marco Russo

Microsoft documentation: https://docs.microsoft.com/en-us/dax/sample-function-dax

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Context Transition

This function performs a Context Transition if called in a Row Context. Click to read more.

Row Context

This expression is executed in a Row Context. Click to read more.

Iterator

Not recommended

The use of this function is not recommended. See Remarks and Related functions for alternatives.

Not recommended

The use of this parameter is not recommended.

Deprecated

This function is deprecated. Jump to the Alternatives section to see the function to use.

Deprecated

This parameter is deprecated and its use is not recommended.

DirectQuery compatibility

Limitations are placed on DAX expressions allowed in measures and calculated columns.
The state below shows the DirectQuery compatibility of the DAX function.

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