estimate_data_size()

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Applies to: ✅ Azure Data Explorer ✅ Azure Monitor ✅ Microsoft Sentinel

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

Syntax

estimate_data_size(columns)

Learn more about syntax conventions.

Parameters

Name Type Required Description
columns string ✔️ 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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