estimate_data_size()

Learn how to use the estimate_data_size() function to return an estimated data size in bytes of the selected columns of the tabular expression.

Returns an estimated data size in bytes of the selected columns of the tabular expression.

Syntax

estimate_data_size(columns)

Parameters

NameTypeRequiredDescription
columnsstring✔️One or more comma-separated column references in the source tabular expression to use for data size estimation. To include all columns, use the wildcard (*) character.

Returns

The estimated data size in bytes of the referenced columns. Estimation is based on data types and actual values. For example, the data size for the string '{"a":"bcd"}' is smaller than the dynamic value dynamic({"a":"bcd"}) because the latter’s internal representation is more complex than that of a string.

Example

The following example calculates the total data size using estimate_data_size().

range x from 1 to 10 step 1                    // x (long) is 8 
| extend Text = '1234567890'                   // Text length is 10  
| summarize Total=sum(estimate_data_size(*))   // (8+10)x10 = 180

Output

Total
180

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